CN111496200B

CN111496200B - Horizontal continuous casting method of copper alloy

Info

Publication number: CN111496200B
Application number: CN202010334809.3A
Authority: CN
Inventors: 王宏涛; 方攸同; 刘嘉斌; 方晓阳; 张进东; 王立天; 孟亮
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-11-05
Anticipated expiration: 2040-04-24
Also published as: CN111496200A; JP2022023782A; JP7262129B2

Abstract

The invention discloses a horizontal continuous casting method of copper alloy, which horizontally continuously casts a copper alloy melt in a holding furnace below the side of the holding furnace: at least one multi-path water-cooled crystallizer is arranged below the side of the heat preservation furnace, 3 groups of independent cooling units are sequentially arranged on the multi-path water-cooled crystallizer along the primary blank leading-out direction, and the 1 st group of cooling units is closest to the heat preservation furnace; the temperature of the water inlet of each group of cooling units is lower than 20 ℃, and the temperature gradients of 3 groups of cooling units are controlled; the outer walls of the water cooling jackets of the 1 st group and the 2 nd group of cooling units of the multi-path water-cooled crystallizer are provided with electromagnetic induction coils to realize electromagnetic stirring, and the outlet of the multi-path water-cooled crystallizer is provided with a water curtain spray cooling device to cool the initial blank, so that the as-cast initial blank with alloy elements in a supersaturated solid solution state is obtained. The invention not only can save the high-temperature solid solution link with the largest energy consumption in the traditional high-strength high-conductivity copper alloy preparation process, but also can effectively refine crystal grains and ensure the high strength of the alloy.

Description

Horizontal continuous casting method of copper alloy

The technical field is as follows:

the invention relates to the technical field of nonferrous metal processing, in particular to a horizontal continuous casting method of copper alloy.

Background art:

as a representative conductor material, copper alloys are widely used in the field of electrical engineering. With the development of the 5G information age, higher performance requirements are put on the key copper alloy conductor used. In the case of large-scale integrated circuits, as the degree of circuit integration increases, the power density continues to increase, which requires that the copper alloy as the lead frame of the integrated circuit not only has high strength, but also has high electrical and thermal conductivity, so as to ensure that the thermal effect is as low as possible and the heat is rapidly conducted away. Meanwhile, in order to meet the requirements of semiconductor processes, the lead frame copper alloy must have excellent dimensional accuracy, i.e., the copper alloy must have various characteristics of high strength, high conductivity and high accuracy. Taking the connector of 4G/5G mobile phone as an example, the most common is the copper alloy connector used for the charging interface of the mobile phone. The high-conductivity high-strength high-conductivity high-voltage connector not only needs to have high conductivity to reduce contact resistance and large-current charging heat effect as much as possible, but also needs to have high strength to meet the requirement of continuous miniaturization of size, and also needs to have stress relaxation resistance to keep set plugging force, namely needs to have various characteristics of high strength, high conductivity and stress relaxation resistance.

The development of various high-strength and high-conductivity copper alloys and high-efficiency and high-quality preparation technologies thereof is an important development direction of common concern in the field of copper alloys. At present, material component design around high-strength and high-conductivity copper alloy mainly focuses on binary copper alloy such as copper silver, copper magnesium, copper tin, copper chromium, copper zirconium, copper iron, copper beryllium, copper titanium, copper cadmium and the like; and ternary alloys such as copper iron phosphorus, copper nickel silicon, copper chromium zirconium, and the like; and multi-element complex alloy which is further microalloyed on the basis of the alloy. There are also various methods for preparing high-strength and high-conductivity copper alloys.

Chinese patent application No. 201410530014.4 discloses a copper-silver alloy and its preparation technology. Weighing and calculating the copper and the copper-silver intermediate alloy according to the mass ratio of 80-99 percent of copper (Cu) and 20-1 percent of silver (Ag), mixing and adding the copper and the copper-silver intermediate alloy into a crucible of a vacuum smelting furnace, vacuumizing to 5 multiplied by 10^-1Pa above, starting to heat up, stopping vacuumizing and charging N into the vacuum furnace after the temperature rises to 600-800 DEG C₂Or inert gases to 5X 10₃Pa; and then continuously heating to 1150-1250 ℃, after the copper and the copper-silver intermediate alloy are completely dissolved, starting to fill inert gas into the copper-silver alloy liquid and stir for 20-30 minutes, and cooling the alloy melt to obtain the copper-silver alloy blank.

Chinese patent (application No. 201811196401.3) discloses a copper-magnesium alloy and its preparation technology. Cathode copper and metal magnesium with the copper content of more than or equal to 99.99 percent are directly added into the power frequency induction furnace, and the mass percentage of the magnesium is 0.16 to 0.19 percent. And adding a refining agent into the molten copper, covering the surface of the molten copper with crystalline flake graphite, and finally casting by adopting an upward continuous casting method to obtain the casting rod for the copper-magnesium alloy stranded wire.

Chinese patent application No. 201710931646.5 discloses a copper-tin alloy and its preparation technology. The copper-tin alloy comprises metal tin, metal copper and other impurities, and the weight ratio of each component is as follows: 0.195-0.435% of metal tin, 99.755-99.515% of metal copper and 0.05% of other impurities. Firstly, adding cathode copper as a raw material into an upward-drawing furnace for melting, then adding metallic tin into copper liquid, stirring by a graphite rod to enable alloy components to be uniform, and then starting to draw a blank rod upwards; and then sending the upper lead rod of the alloy containing tin led out from the upper lead rod into a continuous extruder to manufacture an extrusion rod with the diameter of 20mm, then connecting the end part of the extrusion rod with the tail part of the extrusion rod of a pay-off rack of a drawing machine by adopting flash butt welding, marking the continuous part, cutting a finished product of the copper-tin alloy contact wire manufactured by the extrusion rod at the continuous part, and continuously drawing to manufacture the finished product of the copper-tin alloy contact wire.

Chinese patent application No. 201910720284.4 discloses a copper-chromium alloy and its preparation technology. The weight content of the alloy chromium is 5 wt% -50 wt%, and copper metal and chromium metal are matched; under the protection of inert gas, smelting the prepared copper-chromium material powder or block by vacuum non-consumable arc; turning over the copper-chromium alloy block body smelted by the vacuum non-consumable electric arc, and repeatedly smelting for a plurality of times until the alloy sample is completely melted; and continuously melting the completely melted copper-chromium alloy under the protection of inert atmosphere, rapidly quenching the arc after melting, opening a vacuum valve, and carrying out suction casting on the melted copper-chromium alloy liquid into a casting mold by using the acting force of negative pressure to realize rapid cooling solidification to obtain a copper-chromium alloy ingot.

Chinese patent application No. 201610325699.8 discloses a copper-zirconium alloy and its preparation technology. The alloy zirconium accounts for 0.14-0.22%, the zirconium and copper are more than or equal to 99.97%, and the impurity content is less than or equal to 0.03%. The alloy is prepared by the following steps: putting 0.1-0.25% of zirconium and 99.7-99.9% of copper together for casting to obtain a copper-zirconium alloy ingot; sawing off a riser of the copper-zirconium alloy ingot and turning off outer-layer oxide skin to obtain a pure ingot blank; forging the ingot blank to form a copper-zirconium alloy bar blank; carrying out solution heat treatment to obtain a solid-dissolved bar blank; performing secondary forging to obtain a secondary forged bar blank; and carrying out aging heat treatment on the secondary forged bar blank to obtain an alloy blank.

The patent application No. 201810341974.4 discloses a copper-iron alloy and its preparation technology. The alloy comprises 4-20% of Fe, 0.001-1.0% of RE and the balance of Cu, wherein RE is a rare earth element. RE is Ce and La, the content of Ce is 0.008-0.012 wt.%, and the content of La is 0.05-0.06 wt.%. The copper-iron alloy material is prepared by an electroslag remelting method, wherein a copper-iron alloy ingot smelted by a vacuum induction furnace is used as a consumable electrode, and CaF is used₂NaF slag system as slag.

The patent application No. 201380056659.2 discloses a copper-beryllium alloy and a preparation technology thereof. The Cu-Be alloy is a Cu-Be alloy containing Co, wherein the content of Co is 0.005-0.12%, and the content of Be is 1.60-1.95%. The method for producing the Cu-Be alloy comprises the following steps: (1) a melt casting step, (2) a homogenization treatment step, (3) a preprocessing step, (4) a solution treatment step, (5) a cold working step, and (6) an age hardening treatment step.

Chinese patent (application No. 201811313033.6) discloses a copper-titanium alloy and a preparation technology thereof. The alloy comprises the following components in percentage by weight: 2-2.4%, Cr: 0.1 to 0.3%, Ni: 0.1-0.3%, Co: 0.05-0.1% and the balance of Cu. The method for regulating the structure of the alloy comprises the following steps: (1) smelting; (2) milling a surface; (3) hot rolling; (4) and (5) solid solution aging treatment.

Chinese patent application No. 2018111964013 discloses a copper-cadmium alloy and its preparation technology. The cadmium content in the alloy is 31% -70%, the alloy is smelted in a reducing atmosphere, charcoal or cullet is added for covering, a furnace is preheated, cadmium ingots are added, the temperature is raised for melting, when the temperature reaches 400-750 ℃, electrolytic copper subjected to acid cleaning is added, the temperature is continuously raised to 400-750 ℃ after stirring, the electrolytic copper subjected to acid cleaning is added, and the casting is carried out after the steps are repeated and the alloy is kept still for 5-10 minutes.

Chinese patent application No. 201510733708.2 discloses a copper-iron-phosphorus alloy and its preparation technology. The alloy formula is Fe2.1% -2.6%; 0.015 to 0.15 percent of P; 0.05 to 0.20 percent of Zn; pb is less than or equal to 0.03 percent; ni0.01-0.1%; 0.01 to 0.1 percent of Sn; the balance of Cu. The production method comprises the following steps: mixing the raw materials according to a formula ratio, heating, casting, hot rolling, cold rolling, heat treatment, cleaning, stretch bending and straightening, and heat treatment.

Chinese patent application No. 201710531296.3 discloses a copper-nickel-silicon alloy and its preparation technology. The Ni content and the Si content in the alloy are both 0-2%. The preparation technology comprises the following steps: the method comprises the following steps of taking a copper source, a nickel source and a silicon source as raw materials, sequentially carrying out melting, continuous casting, cooling and blank drawing to obtain a copper-nickel-silicon alloy plate blank, and sequentially carrying out rolling, aging treatment, cooling and cold finish rolling on the copper-nickel-silicon alloy plate blank to obtain a copper-nickel-silicon alloy strip.

Chinese patent (application No. 200710053838.7) discloses a copper beryllium silver alloy and a preparation technology thereof. The copper alloy material consists of CU, BE and AG elements and has a continuous fiber structure; the alloy material comprises, by weight, 0.06-0.12 WT% of BE, 0.08-0.15 WT% of AG and the balance of CU. The preparation process of the alloy material includes smelting at 1180-1200 deg.c, drawing with continuous directional solidification and heat treatment at 700-750 deg.c.

Chinese patent (application No. 201910720284.4) discloses a copper-chromium-zirconium alloy and a preparation technology thereof. The alloy material comprises, by weight, 100% of chromium, 0.2% to 0.35% of zirconium, 0.02% to 0.025% of lanthanum and 79.6% to 84.5% of copper. The preparation method comprises the following specific steps: weighing chromium, zirconium, lanthanum and copper as raw materials; smelting copper in a vacuum smelting furnace; after the copper is melted down, chromium is added through a feed inlet to cover the surface of the copper liquid for smelting; after the chromium is melted down, adding zirconium and lanthanum through the feed inlet again for smelting; obtaining a mixed solution after the zirconium and the lanthanum are melted down, smelting the mixed solution, stirring and cooling the mixed solution after the mixed solution is melted down again for casting, and cooling and discharging the mixed solution to obtain an ingot; and carrying out solid solution aging treatment and twice deformation aging treatment on the cast ingot to obtain the copper-chromium-zirconium alloy conducting rod.

Chinese patent (application No. 201310633208.2) discloses a copper-chromium multi-element complex alloy and a preparation technology thereof. The alloy consists of the following components in percentage by weight: 7.5 to 8.5 weight percent of Cr, 0.2 to 0.4 weight percent of Al, 0.3 to 0.5 weight percent of Sn, 0.04 to 0.06 weight percent of Co, 0.05 to 0.10 weight percent of Sr and the balance of copper. The preparation method comprises the steps of high-temperature smelting, cooling and the like.

Chinese patent (application No. 201410474358.8) discloses a copper-titanium complex alloy and a preparation technology thereof. The copper-titanium alloy material comprises the following components: 3.9 to 7.8 weight percent of Ti, 1.2 to 1.8 weight percent of Cr, 0.4 to 0.9 weight percent of Ca, 0.3 to 0.8 weight percent of Ni, 0.2 to 0.5 weight percent of V, 0.7 to 1.2 weight percent of Zn and the balance of Cu. The preparation method comprises the steps of vacuum step-by-step smelting, cooling and the like.

Chinese patent (application No. 201510976079.6) discloses a high-strength high-conductivity copper-chromium-zirconium alloy and a preparation method thereof, wherein the alloy comprises the following chemical compositions: cr: 0.01 to 1.5 wt%, Zr: 0.01-0.5 wt%, Ti: 0.001 to 0.5 wt%, Mn: 0.01-0.5 wt%, Ca: 0.0001-0.07 wt%, and the balance of copper and inevitable impurities. The preparation process comprises the following steps: batching → fusion casting → sawing → homogenizing annealing → hot rolling → primary solution treatment → surface milling → primary cold rolling → secondary solution treatment → secondary cold rolling → primary aging treatment → tertiary cold rolling → secondary aging treatment → pulling and straightening.

Chinese patent (application No. 201711414445.4) discloses a preparation method of a copper-chromium-zirconium alloy strip for a lead frame, wherein the copper-chromium-zirconium alloy strip comprises, by weight, 1.0% -1.5% of chromium, 0.1-0.15% of zirconium, 0.01-0.015% of silver, 0.01-0.015% of cobalt, 0.1-0.15% of beryllium, 0.1-0.15% of titanium, 0.1-0.15% of tin, 0.1-0.15% of magnesium, 0.1-0.15% of niobium, 0.1-0.15% of indium, and the balance of copper. The preparation method of the alloy comprises the following steps: the method comprises the following steps of upward continuous casting, continuous extrusion, first rolling, first solid solution, second rolling, first aging, second solid solution, third rolling, second aging, fourth rolling, third aging and finishing.

Chinese patent (application No. 201710012956.7) discloses a method for producing precipitation strengthening type high-strength copper-chromium alloy by continuous casting and continuous extrusion, which adopts a horizontal continuous casting method to form a copper alloy rod, directly produces a blank by continuous extrusion after on-line heating and solid solution, and then obtains a product with the performance and the size meeting the requirements after cold rolling and aging treatment and finishing. The invention adopts the continuous extrusion process to produce the high-performance copper-chromium-zirconium alloy material, simplifies the production process to a certain extent, removes the working procedures of surface milling, hot rolling cogging, primary rolling and the like, reduces intermediate rolling passes, reduces the equipment investment of enterprises, reduces the energy consumption, and improves the production efficiency and the product yield.

Similar related data are not listed, and it is known from the published data that the research on the composition design of high-strength and high-conductivity copper alloys is extensive at present, and various alloy compositions are proposed. There are various methods for preparing high-strength and high-conductivity copper alloy, and some of them have already been industrially produced. However, these methods are basically the traditional three-stage processing method of copper alloy, i.e. smelting ingot casting, hot working and cold working, and proper heat treatment process, wherein the hot working includes hot extrusion, hot rolling, hot forging, solid solution, etc., and the cold working includes cold rolling, cold drawing, etc. The preparation methods of the high-strength and high-conductivity copper alloy have the problems of multiple working procedures, high energy consumption, low yield, high production cost and equipment investment and to-be-improved copper alloy performance.

Therefore, the key innovation direction of the high-performance copper alloy processing industry is short flow, continuity, energy conservation, low investment, low cost and guarantee of high strength and high conductivity of the copper alloy.

Currently, the preparation technology of high-strength and high-conductivity copper alloy mainly comprises technical methods such as 'up-drawing continuous casting-solid solution-continuous extrusion-cold rolling', 'vacuum casting-hot rolling cogging-cold rolling-solid solution-finish rolling-heat treatment', 'horizontal continuous casting-online solid solution-continuous extrusion-cold rolling-aging' and the like. In the preparation of a cast slab, horizontal continuous casting is recognized as a high, fine, and sharp continuous casting technique that provides a high-quality cast slab. However, in the existing copper alloy preparation methods introducing the horizontal continuous casting process, a casting blank with alloy elements all in a supersaturated solid solution state cannot be obtained in the horizontal continuous casting process, so that the alloy elements in the casting blank are in the supersaturated solid solution state by further high-temperature solid solution treatment on the casting blank, and the energy saving aspect still needs to be improved. The existing continuous extrusion process also generally has the problem of advanced desolventizing and decomposing of supersaturated solid solution, so that the strength and the conductivity of the copper alloy are influenced. If it is desired to have the material in a solid solution state before aging, it is most straightforward to perform a high temperature solid solution heat treatment before aging, however, this approach is not only energy intensive, but also results in a complete loss of the prior cold-hardening effect.

Therefore, in the high-performance copper alloy processing industry, how to make alloy elements in a horizontal continuous casting blank in a supersaturated solid solution state so as to avoid a subsequent high-temperature solid solution link and how to avoid desolventizing decomposition of the copper alloy solid solution state in a continuous extrusion process and ensure high-strength and high-conductivity performance of the copper alloy is a technical problem to be solved urgently.

The invention content is as follows:

the invention aims to solve the first technical problem of providing a horizontal continuous casting method of copper alloy, which can enable alloy elements in an as-cast primary blank to be in a supersaturated solid solution state, not only can save the high-temperature solid solution link with the largest energy consumption in the traditional high-strength high-conductivity copper alloy preparation process, reduce the energy consumption, but also can effectively refine crystal grains and ensure the high strength of the alloy.

The second technical problem to be solved by the invention is to provide the application of the horizontal continuous casting method of the copper alloy in preparing the copper alloy, which can shorten the process, reduce the energy consumption and the cost, improve the product forming rate and ensure the high strength of the copper alloy.

In order to achieve the purpose, the invention adopts the following technical scheme:

on the first hand, in order to realize that the alloy elements in the horizontal continuous casting primary billet are in a supersaturated solid solution state, the invention increases the cooling strength in the horizontal continuous casting process to ensure that the primary billet has a high cooling solidification rate, and particularly, the following 3-point technology is adopted to ensure the high cooling strength of the horizontal continuous casting: (1) a multi-path water-cooled crystallizer is used, 3 groups of independent cooling units are arranged along the primary blank leading-out direction of the crystallizer, multi-path water inlet and multi-path water outlet are realized, a reverse cooling mode is adopted, namely, water inlet is carried out at the cold end, water outlet is carried out at the hot end, and a proper rapid cooling effect is ensured through certain technical parameter design; (2) considering that the rapid cooling may cause the viscosity of the metal melt to increase rapidly to cause casting defects such as billet breakage, holes and the like, an electromagnetic stirring device is arranged for electromagnetic stirring to reduce the viscosity, and the continuous horizontal continuous casting is ensured; (3) and (3) strongly cooling the initial blank at the outlet of the crystallizer to avoid the desolventizing of the solid solution part.

The invention specifically provides a horizontal continuous casting method of copper alloy, which is characterized in that a copper alloy melt in a heat preservation furnace is horizontally continuously cast below the side of the heat preservation furnace to obtain an as-cast initial blank with alloy elements in a supersaturated solid solution state: at least one multi-path water-cooled crystallizer is arranged below the side of the heat preservation furnace, 3 groups of independent cooling units are sequentially arranged on the multi-path water-cooled crystallizer along the leading-out direction of the primary blank, multi-path water inlet and multi-path water outlet are realized, a reverse cooling mode (namely cold end water inlet and hot end water outlet) is adopted, and the 1 st group of cooling units is closest to the heat preservation furnace; the temperature of the water inlet of each group of cooling units is lower than 20 ℃, and the temperature gradient of 3 groups of cooling units is controlled by the following method: the water flow V3 and the sectional area S of the blank of the 3 rd group cooling unit are required to satisfy 0.5L/(min mm. mm)²)<V3/S<2L/(min·mm²) The water flow rate V2 of the cooling unit of the 2 nd group and the water flow rate V1 of the cooling unit of the 1 st group are determined according to the principle of V1: V2: V3: 1.5:1.2: 1; arranging electromagnetic induction coils on the outer walls of the water cooling jackets of the 1 st group and the 2 nd group of cooling units of the multi-path water-cooled crystallizer to realize electromagnetic stirring, wherein the electromagnetic stirring mode is rotary stirring, and the current frequency is set to be 2-500 Hz; controlling the sectional area S of the primary blank to be 50-2000 mm²The extraction speed v and the sectional area of the initial blank need to meet the requirement that S/v is less than or equal to 0.5mm & min and less than or equal to 20mm & min; the method is characterized in that a water curtain spraying cooling device is arranged in the range of 1000mm outwards from the outlet of the multi-path water-cooled crystallizer to cool a primary blank, atomizing nozzles are adopted by the spraying device, the interval between the nozzles is 10-20 mm, the number of the nozzles is set according to the size of the blank, the distance between the nozzles and the surface of the blank is 10-50 mm, and the water pressure is 0.5-0.8 MPa, so that the cast-state primary blank with alloy elements in a supersaturated solid solution state is obtained.

In order to realize high-efficiency production, a set of horizontal continuous casting system can be matched with a plurality of crystallizers, for example, 2-4 crystallizers are matched to realize continuous extraction of 2-4 primary blanks, the arrangement modes of the crystallizers are arranged in a straight line at intervals of 200-400 mm, and each set of crystallizer is provided with an independent water cooling and electromagnetic device.

According to the invention, the alloy elements in the primary blank are in a supersaturated solid solution state through horizontal continuous casting, namely, the alloy elements are ensured to exist in a copper matrix in a solid solution atom form, namely, a supersaturated copper solid solution is formed, so that a high-temperature solid solution link with the largest energy consumption in the traditional process can be saved, and the primary blank obtained by horizontal continuous casting has the possibility of directly carrying out subsequent continuous extrusion.

In a second aspect, the invention provides the use of the horizontal continuous casting method for the production of copper alloys.

Preferably, the application comprises the following steps:

(a) obtaining an as-cast primary blank of the copper alloy by the horizontal continuous casting method, wherein alloy elements in the obtained as-cast primary blank are in a supersaturated solid solution state;

(b) and (b) directly carrying out continuous extrusion, cold working and aging annealing on the cast-state primary blank obtained in the step (a) after skinning to obtain a copper alloy, and keeping alloy elements of the blank in a supersaturated solid solution state in the continuous extrusion process.

The present invention is particularly preferred to maintain the alloying elements in the billet in a supersaturated solid solution state during the subsequent continuous extrusion process. Thus, the cast structure is fully crushed and the crystal grains are refined through continuous extrusion, a large amount of dislocation generated by cold machining is superposed, so that the alloy has high crystal defects, the alloy is ensured to have high strength characteristic, then aging annealing is assisted, and the dislocation core is used as a rapid channel for atomic diffusion to disperse and separate out alloy elements in a second-phase nano particle mode, so that the copper matrix is purified to restore the high conductivity of the alloy, the dislocation line is pinned to generate a dispersion hardening effect, the cold machining deformation energy is released, and the stress cracking is avoided. Most importantly, the design of the horizontal continuous casting and continuous extrusion process ensures that the supersaturated solid solution state of the copper alloy is kept from the casting stage until the precipitation is controlled during the aging annealing treatment; due to the uniform solid solution state property, the material can be ensured to deform uniformly in the intermediate processing stage, and the yield of the product is improved; meanwhile, the precipitation power accumulated in the solid solution state is uniformly released in a uniform temperature field in the aging annealing treatment stage, so that the precipitation power is strong, the precipitation behavior is controllable, and uniform precipitation tissues are generated, thereby ensuring the consistency of performance.

In order to ensure that alloy elements in the blank keep a supersaturated solid solution state in the continuous extrusion process, the invention designs the following 3 technical means for combined use:

1) the die and the casting blank are preheated at high temperature, so that desolvation and decomposition of the supersaturated solid solution are avoided;

2) continuous extrusion with large extrusion ratio: the continuous extrusion parameters with large extrusion ratio are adopted, so that on one hand, a sufficiently high deformation temperature is ensured to prevent solid solution from desolventizing, and on the other hand, the casting blank is subjected to severe plastic deformation in a die cavity to fully crush an as-cast structure to form a recrystallized structure;

3) and (3) rapid cooling: through high-strength cooling, the blank is rapidly cooled from high temperature to room temperature, and desolventizing decomposition of the supersaturated solid solution is avoided.

The technical means can be combined to realize double purposes: the first cast structure is subjected to severe plastic deformation, so that the uniformity and the strength of the structure are improved; and secondly, the premature desolventizing decomposition of the supersaturated solid solution is avoided. However, the high temperature and high extrusion ratio continuous extrusion leads to a die cavity working temperature and working pressure which are significantly higher than those of the conventional continuous extrusion, which easily causes the blank car and the die to burst. Therefore, the extruder power must be increased and a superalloy die must be used.

Therefore, the preferred process conditions for continuous extrusion in the present invention are:

(1.1) the extrusion die employs a forged high temperature nickel-based alloy comprising 0.05 wt.% C, 15 wt.% Cr, 6 wt.% Mo, 5 wt.% W, 2 wt.% Ti, 5.5 wt.% Al, and the balance Ni; the alloy is smelted through a vacuum smelting and electroslag remelting process, and is formed through hot forging and heat treatment after homogenization treatment;

(1.2) preheating an extrusion die to 500-600 ℃ before the extrusion is started, preheating the as-cast copper alloy primary blank to 700-750 ℃, then extruding the copper alloy primary blank into a die cavity, controlling the rotating speed of an extrusion wheel to be 3-8 rpm, the extrusion ratio to be 3-8 and the extrusion gap to be 0.6-2mm, so that on one hand, a sufficiently high deformation temperature is ensured to prevent solid solution desolventizing, on the other hand, the copper alloy primary blank is softened, the deformation resistance is reduced, and the metal plastic flow capacity is increased;

(1.3) spraying high-strength cooling water at the outlet of the extrusion die, spraying by using an atomizing nozzle instead of conventional small holes by using a spraying device, wherein the interval between the nozzles is 10-20 mm, the number of the nozzles is set according to the size of the blank, the distance between the nozzles and the surface of the blank is 10-50 mm, and the water pressure is 0.5-0.8 MPa, so that the blank is rapidly cooled to room temperature from high temperature, and desolventizing decomposition of supersaturated solid solution is avoided.

In the invention, the preparation of the forged high-temperature nickel-based alloy can refer to the prior art, and is particularly recommended to be prepared according to the following steps: smelting an alloy ingot by adopting a vacuum smelting and electroslag remelting process, carrying out homogenization treatment on the alloy ingot at 1250 ℃ for 1-4 h, and carrying out isothermal forging forming at 1000-1050 ℃, wherein the deformation amount is 80-90%; then, the temperature is kept at 800 ℃ for 8-16 hours, and the tempering is carried out for 1-2 hours at 300-400 ℃ after quenching water cooling. The forged high-temperature nickel-based alloy has very good high-temperature mechanical property, can be used as a continuous extrusion die, and particularly can be used as a plug component with the most severe service requirement.

In the present invention, cold rolling, cold drawing, or the like may be used as the cold working. In order to ensure the deformation amount of cold working, the pass deformation amount of the cold working is further preferably 5-10%, and the accumulated deformation amount is 50-99%, so that obvious plastic deformation is generated in the blank, and a large amount of dislocation tangles are formed.

In the invention, in order to ensure sufficient annealing, the annealing temperature is required to be 300-600 ℃, and the heat preservation time is 0.5-100 h. The annealing temperature and the holding time are particularly preferably selected according to the following principle: taking cold-processed blank samples, and respectively preserving heat at 300, 350, 400, 450, 500, 550 and 600 ℃ for 0.1, 0.5, 1, 2, 4, 8, 16, 24, 48 and 99.6 h; and testing the Vickers hardness (unit HV) and the conductivity (unit% IACS) of the sample, calculating the product of the hardness value and the conductivity value, taking the test temperature of the sample with the maximum product as the annealing temperature of the product, and taking the test time of the sample with the maximum product plus 0.4h as the annealing holding time of the product.

The preparation method of the copper alloy mainly comprises 4 core steps of horizontal continuous casting, continuous extrusion, cold processing and aging annealing, and is flexibly matched according to designed products: preparing materials, peeling, sampling, rolling, uncoiling, slitting, packaging and the like. A typical preparation scheme is as follows: according to the material proportioning of the designed product, smelting in a horizontal continuous casting furnace, preserving heat and horizontally casting an initial blank; peeling the primary blank; and (3) feeding the blank into a continuous extruder for extrusion, extruding the blank into a preset shape, then carrying out cold machining to a preset size, then carrying out aging annealing, and finally slitting, packaging and leaving the factory.

The invention particularly preferably applies the following steps:

(1) melting the ingredients: batching according to copper alloy components, putting the copper alloy components into a melting furnace for full melting, sampling, detecting and analyzing the oxygen content and the alloy element content, supplementing materials according to the analysis result, fully deoxidizing, and then guiding the melt into a holding furnace through a guide groove in the melting furnace;

(2) horizontal continuous casting: carrying out horizontal continuous casting below the side of the heat preservation furnace, installing at least one multi-path water-cooled crystallizer below the side of the heat preservation furnace, sequentially arranging 3 groups of independent cooling units along the leading-out direction of the primary blank for realizing multi-path water inlet and multi-path water outlet, and adopting a reverse cooling mode, namely, water inlet at a cold end and water outlet at a hot end, wherein the 1 st group of cooling units is closest to the heat preservation furnace; the temperature of the water inlet of each group of cooling units is lower than 20 ℃ (if the actual water temperature in summer exceeds 20 ℃, a preposed cooling device needs to be configured), and the temperature gradients of the three groups of cooling units are controlled by the following modes: the water flow V3 of the cooling unit in the 3 rd group and the sectional area S of the initial blank are 0.5L/(min mm)²)<V3/S<2L/(min·mm²) The water flow rate V2 of the cooling unit in the 2 nd group and the water flow rate V1 of the cooling unit in the 1 st group are determined according to the principle that V1: V2: V3 is 1.5:1.2:1, so that the cooling capacities of the three groups of cooling units with different strengths are matched to form a reasonable temperature gradient; water cooling of cooling units in groups 1 and 2 of the crystallizerAn electromagnetic induction coil is arranged on the outer wall of the sleeve to realize electromagnetic stirring, the electromagnetic stirring mode is rotary stirring, and the current frequency is set to be 2-500 Hz; the sectional area S of the primary blank is 50-2000 mm²The extraction speed v and the sectional area of the initial blank are determined according to the principle that S/v is more than or equal to 0.5mm & min and less than or equal to 20mm & min; a water curtain spray cooling device is arranged in the range of 1000mm outwards from the outlet of the crystallizer to cool the primary blank, and the spray device adopts an atomizing nozzle instead of a conventional small hole for spraying; the interval of the nozzles is 10-20 mm, the number of the nozzles is set according to the size of the blank, the distance between the nozzles and the surface of the blank is 10-50 mm, and the water pressure is 0.5-0.8 MPa;

(3) continuous extrusion: peeling an as-cast primary blank obtained by horizontal continuous casting, and then directly carrying out continuous extrusion, preheating an extrusion die to 500-600 ℃, rapidly preheating the as-cast primary blank subjected to peeling to 700-750 ℃ through an online induction device, then feeding the as-cast primary blank into a die cavity of the extrusion die for extrusion, controlling the rotating speed of an extrusion wheel to be 3-8 rpm, the extrusion ratio to be 3-8, and the extrusion gap to be 0.6-2 mm; the blank is rapidly cooled from high temperature to room temperature by adopting high-strength cooling water spraying at the outlet of the extrusion die, the spraying device adopts atomizing nozzles, the interval of the nozzles is 10-20 mm, the number of the nozzles is set according to the size of the blank, the distance between the nozzles and the surface of the blank is 10-50 mm, and the water pressure is 0.5-0.8 MPa; the extrusion die is made of a forged high-temperature nickel-based alloy, comprises 0.05 wt.% of C, 15 wt.% of Cr, 6 wt.% of Mo, 5 wt.% of W, 2 wt.% of Ti, 5.5 wt.% of Al and the balance of Ni, is smelted by a vacuum smelting and electroslag remelting process, and is formed by hot forging and heat treatment after homogenization treatment;

(4) cold processing: cold working is carried out on the continuously extruded blank according to the product requirement, the pass deformation of the cold working is 5-10%, and the accumulated deformation is 50-99%;

(5) aging annealing treatment: coiling the cold-processed blank, placing the blank in a bell-type heating furnace, carrying out aging annealing treatment, placing the blank in an inner liner, hoisting the inner liner to cover the inner liner after a furnace body to be heated reaches a preset temperature, quickly heating the blank, hoisting the furnace body away by a crane after the preset heat preservation time is reached, quickly cooling the blank, and introducing reducing atmosphere to avoid oxidation in the whole heat treatment process; the aging annealing temperature and time of the product are determined by the following principles: taking a plurality of groups of cold-processed blank samples, and respectively annealing at 300, 350, 400, 450, 500, 550 and 600 ℃ for 0.1, 0.5, 1, 2, 4, 8, 16, 24, 48 and 99.6 h; testing the Vickers hardness (unit HV) and the conductivity (unit% IACS) of the sample, calculating the product of the hardness value and the conductivity value, taking the test temperature of the sample with the maximum product as the annealing temperature of the product, and taking the test time of the sample with the maximum product plus 0.4h as the annealing heat preservation time of the product;

(6) and (5) inspecting, packaging and leaving factory.

The preparation method of the copper alloy is mainly aimed at high-strength and high-conductivity copper alloys, and is particularly suitable for precipitation strengthening type high-strength and high-conductivity copper alloys, such as Cu-X binary alloys, Cu-X-Y ternary alloys, multi-element alloys and other high-copper alloys listed in the background technology.

By adopting the technical scheme, the invention can achieve the following technical effects:

(1) the horizontal continuous casting of the invention ensures that the alloy elements in the primary blank are in a supersaturated solid solution state, so that the invention breaks through the traditional copper processing three-stage process, saves the high-temperature solid solution link with great energy consumption, greatly shortens the process flow, can effectively refine crystal grains, improves the uniformity of the structure and ensures the high strength of the alloy.

(2) The preparation of the copper alloy realizes the continuous operation of casting, extruding and cold processing, shortens the process flow, obviously improves the production takt and increases the production capacity.

(3) The continuous extrusion of the invention can keep the supersaturated solid solution state of the copper alloy, and the high-density dislocation entanglement is generated on the solid solution state copper matrix by utilizing the severe deformation of the continuous extrusion and the large deformation of cold processing, thereby ensuring that the alloy has the characteristic of high strength; and then, by utilizing the characteristic of a dislocation core rapid diffusion channel, the alloy elements are promoted to be fully dispersed and separated out in the subsequent aging annealing treatment, the copper matrix is purified, and the high conductivity characteristic of the copper alloy is ensured.

(4) The core idea of the preparation of the copper alloy is to keep the supersaturated solid solution state of the copper alloy from the beginning of the casting stage until the controllable precipitation is carried out during the aging annealing treatment. Due to the uniform solid solution state property, the material can be ensured to deform uniformly in the intermediate processing stage, and the yield of the product is improved. Meanwhile, the precipitation power accumulated in the solid solution state is uniformly released in a uniform temperature field in the aging annealing treatment stage, so that the precipitation power is strong, the precipitation behavior is controllable, and uniform precipitation tissues are generated, thereby ensuring the consistency of performance.

Description of the drawings:

FIG. 1: a TEM photograph of the copper alloy product of example 1 shows a large amount of fine Ag precipitates inside the Cu-0.5 wt.% Ag alloy product obtained by the method of the present invention.

FIG. 2: metallographic pictures of cross sections of as-cast primary ingots obtained by horizontal continuous casting of examples 1-1 show as-cast equiaxed grain structures of Cu-0.5 wt.% Ag alloys obtained by the method of the present invention.

FIG. 3: the XRD patterns of the as-cast primary blank of example 1-1 and the aged product of example 1 show the supersaturated solid solution structure of the as-cast primary blank and the precipitated structure characteristics of the aged Ag second phase.

FIG. 4: TEM micrograph of the copper alloy product of example 4, showing a large amount of fine Cr, Zr precipitates inside the Cu-0.7 wt.% Cr-0.15 wt.% Zr alloy product obtained by the method of the present invention.

FIG. 5: example 1 metallographic pictures of the cooled billet after continuous extrusion showing a recrystallized structure.

FIG. 6: example 1 TEM photographs of the continuously extruded cooled billet show that no nano precipitated phase is generated inside the extruded state, indicating that the supersaturated solid solution characteristics are still maintained.

FIG. 7: examples 1-7 photographs of a horizontal continuous casting multiple break of a billet illustrate that an unreasonable continuous casting process results in a break of the billet.

FIG. 8: TEM photographs of horizontally cast billets of examples 1-8 show premature precipitation of Ag phases due to insufficient cooling.

FIG. 9: the actual picture of extrusion die failure of example 9 illustrates the necessity to use die steel with excellent mechanical properties at high temperatures.

FIG. 10: TEM photographs of the continuously extrusion-cooled billet of example 11 show that the supersaturated solid solution is previously desolventized to precipitate an inhomogeneous coarse Ag phase due to insufficient cooling after extrusion.

FIG. 11: example 22 TEM photographs of the continuously extruded cooled billet were taken and it was observed that Ag precipitate phase had appeared in the structure, indicating that the solid solution had been partially desolventized.

FIG. 12: the horizontally continuously cast as-drawn primary billets of examples 1-15.

FIG. 13: low magnification metallographic structure pictures of the horizontally continuously cast-out primary ingots of examples 1 to 15.

FIG. 14: high power metallographic structure pictures of the horizontally continuously cast-out primary ingots of examples 1-15, no significant precipitated phase was found inside the grains.

FIG. 15: the XRD patterns of the horizontal continuous casting-derived primary ingots of examples 1 to 15 have only diffraction peaks of copper, and no diffraction peaks of the second phase. The diffraction peak is shifted from the standard copper diffraction peak, which shows that the chromium zirconium element is dissolved in the copper crystal lattice.

FIG. 16: metallographic structure photographs of the continuously extruded billet of example 25 showed an equiaxed structure.

FIG. 17: example 25 TEM photographs of the continuously extruded cooled billet show that no nano precipitated phase is generated inside the extruded state, indicating that the supersaturated solid solution characteristics are still maintained.

FIG. 18: TEM texture photograph of the cold rolled blank of example 25, showing high density dislocation entanglement.

FIG. 19: TEM micrograph of aged sample of example 25 shows high density precipitated phase.

FIG. 20: high resolution TEM histograms of the aged samples of example 25 show images of the lattice fringes of the nanophase precipitates.

FIG. 21: examples 1-16 metallography of horizontally continuously cast primary billets.

FIG. 22: examples 1-21 metallography of horizontally continuously cast primary billets, the arrows indicating the primary chromium phase, indicate that primary dendrites have formed.

FIG. 23: the horizontal continuous casting blank breaking objects of the examples 1 to 22 show that the extraction speed and the cooling strength must be reasonably matched, otherwise, the high-efficiency and high-quality casting of the copper-chromium-zirconium primary blank cannot be realized.

FIG. 24: example 36 TEM tissue photographs of samples after continuous extrusion showing coarse chromium precipitates.

FIG. 25: the structural design drawing of the extrusion die for continuous extrusion in embodiment 25 of the present invention is a bilaterally symmetric structure, the included angle between the AB line and the AD line is 105 °, the included angle between the CD line and the DA line is also 105 °, and the length of the BC right-side semicircle diameter is the length of the BC line segment.

FIG. 26: in the structural design drawing of the extrusion die for continuous extrusion in the embodiment 1 of the invention, the ratio d/a of the diameter d of the circular cavity to the side length a of the die is less than 0.5.

The specific implementation mode is as follows:

the technical solution of the present invention is further illustrated by the following specific examples, but the scope of the present invention is not limited thereto:

example 0: preparation example of forged high temperature nickel-based alloy:

an alloy ingot is smelted by adopting a vacuum smelting and electroslag remelting process, and comprises the following components: 0.05 wt.% C, 15 wt.% Cr, 6 wt.% Mo, 5 wt.% W, 2 wt.% Ti, 5.5 wt.% Al, and the balance Ni. The alloy ingot was subjected to homogenization treatment at 1250 ℃ for 1 hour, and then subjected to isothermal forging at 1000 ℃ to be formed, with a strain amount of 80%. Then, the alloy is kept at 800 ℃ for 16 hours, quenched and cooled, and then tempered at 350 ℃ for 1 hour, and the tensile property of the alloy at room temperature to 800 ℃ is tested, and the result is shown in a table 1:

TABLE 1 high temperature mechanical Properties of the alloys

Temperature/. degree.C	Tensile strength/MPa	Yield strength/MPa	Elongation percentage/％
				At room temperature	1200	1100	8
500	1220	1120	9
				800	1280	1150	9

Example 1-1:

the first step is as follows: melting the ingredients: proportioning Cu-0.5 wt.% Ag according to alloy components, putting the mixture into a melting furnace for full melting, sampling, detecting and analyzing the oxygen content and the alloy element content, supplementing materials according to the analysis result, fully deoxidizing to be within 10ppm, and guiding the melt into a holding furnace through a guide groove in the melting furnace.

The second step is that: horizontal continuous casting: the method comprises the following steps of carrying out horizontal continuous casting below the side of a heat preservation furnace, horizontally arranging 2 crystallizers with the interval of 400mm below the side of the heat preservation furnace, arranging 3 groups of independent cooling units along the primary blank leading-out direction of the crystallizers, and enabling the 1 st group of cooling units to be closest to the heat preservation furnace. The temperature of the water inlet is lower than 20 ℃ by adopting a reverse cooling mode. The water flow V3 of the 3 rd group of cooling units is 2000L/min, the water flow V2 of the 2 nd group of cooling units is 2400L/min, the water flow V1 of the 1 st group of cooling units is 3000L/min, electromagnetic induction coils are arranged on the outer walls of water cooling jackets of the 1 st and 2 nd group of cooling units of the crystallizer to realize electromagnetic stirring, the electromagnetic stirring mode is rotary stirring, and the current frequency is 500 Hz. The sectional area of the primary blank is 2000mm²The drawing speed was 100 mm/min. Water is carried out within the range of 1000mm from the outlet of the crystallizerAnd (3) curtain spraying, wherein 90 atomizing nozzles are arranged, the interval between the atomizing nozzles is 10mm, the distance between the nozzles and the surface of the blank is 10mm, and the water pressure is 0.8 MPa.

The fine equiaxed grain structure of the as-cast condition can be seen from fig. 2, and the absence of the second phase (Ag) detected by XRD of the as-cast condition primary blank can be seen from fig. 3, demonstrating the supersaturated solid solution structure characteristic of the as-cast condition primary blank.

Examples 1 to 2:

the second step is that: horizontal continuous casting: 4 crystallizers are used at intervals of 200mm, the water flow V3 of the cooling unit in the 3 rd group is 100L/min, the water flow V2 of the cooling unit in the 2 nd group is 120L/min, the water flow V1 of the cooling unit in the 1 st group is 150L/min, the electromagnetic stirring frequency is 2Hz, the sectional area of the bloom is 50mm²The leading-out speed is 100mm/min, 30 atomizing nozzles are arranged, the nozzle interval is 20mm, the distance between the nozzles and the surface of the blank is 50mm, and the water pressure is 0.5 MPa.

The remaining steps and parameters were the same as in example 1-1.

Similar to example 1-1, the XRD pattern of the as-cast primary ingot showed a supersaturated solid solution structure.

Examples 1 to 3:

the first step is as follows: melting the ingredients: the alloy composition was Cu-0.7 wt.% Cr-0.15 wt.% Zr.

The remaining steps and parameters were the same as in example 1-1.

Wherein the XRD pattern of the as-cast primary ingot shows that it has a supersaturated solid solution structure.

Examples 1 to 4:

The second step is that: horizontal continuous casting: 3 crystallizers are used at intervals of 300mm, the water flow V3 of the cooling unit in the 3 rd group is 200L/min, the water flow V2 of the cooling unit in the 2 nd group is 240L/min, the water flow V1 of the cooling unit in the 1 st group is 300L/min, the electromagnetic stirring frequency is 50Hz, the sectional area of the bloom is 200mm²The drawing speed was 50 mm/min.

The remaining steps and parameters were the same as in example 1-1.

Examples 1 to 5:

the first step is as follows: melting the ingredients: the alloy composition is Cu-3 wt.% Ni-1 wt.% Si.

The remaining steps and parameters were the same as in example 1-1.

The XRD pattern of its as-cast primary ingot showed a supersaturated solid solution structure.

Examples 1 to 6:

the first step is as follows: melting the ingredients: the alloy composition is Cu-2 wt.% Fe-0.1 wt.% P.

The remaining steps and parameters were the same as in example 1.

From the results of examples 1-1 to 1-6, it is understood that the horizontal continuous casting method of the present invention has good applicability to common Cu-X binary alloys (e.g., Cu-Ag) and Cu-X-Y ternary alloys (e.g., Cu-Fe-P, Cu-Cr-Zr, Cu-Ni-Si).

Examples 1 to 7:

the second step is that: horizontal continuous casting: 4 crystallizers are used at intervals of 200mm, the water flow V3 of the cooling unit in the 3 rd group is 100L/min, the water flow V2 of the cooling unit in the 2 nd group is 120L/min, the water flow V1 of the cooling unit in the 1 st group is 150L/min, the electromagnetic stirring frequency is 2Hz, the sectional area of the bloom is 50mm²The leading-out speed is 200mm/min, 30 atomizing nozzles are arranged, the interval between the atomizing nozzles is 10mm, the distance between the nozzles and the surface of the blank is 10mm, and the water pressure is 0.8 MPa.

The remaining steps and parameters were the same as in example 1-1.

By comparing examples 1-1 and 1-7, it is understood that if the initial billet with a smaller cross section is cooled by spraying at a higher extraction speed, the cooling effect is enhanced and the solid solution is more sufficient, but the solidification is too fast to cause the phenomenon of billet breakage (fig. 7), thereby greatly damaging the production continuity.

Examples 1 to 8:

the second step is that: horizontal continuous casting: the electromagnetic stirring frequency is 2Hz, the extraction speed is 50mm/min, and the water pressure is 0.2 MPa.

The remaining steps and parameters were the same as in example 1-1.

By comparing examples 1-1 and 1-8, it can be seen that if the extraction speed is low, the electromagnetic stirring frequency is low, and the cooling water pressure is low, the stirring of the copper alloy melt is insufficient, fine isometric crystals cannot be formed, a part of Ag atoms are precipitated from the supersaturated solid solution in advance, and evolve into a coarse primary phase (fig. 8), thereby weakening the alloy strength, and simultaneously causing the subsequent precipitation to be insufficient, and damaging the alloy conductivity. Therefore, the technological parameters such as the extraction sectional area, the extraction speed, the cooling water pressure, the electromagnetic stirring frequency and the like must be reasonably matched.

Examples 1 to 9:

the second step is that: the water flow V3 of the cooling unit of group 3 is 4000L/min, the water flow V3 of the cooling unit of group 2 is 4800L/min, and the water flow V1 of the cooling unit of group 1 is 6000L/min.

The remaining steps and parameters were the same as in example 1.

Examples 1 to 10:

the second step is that: the water flow V3 of the cooling unit of group 3 is 1000L/min, the water flow V3 of the cooling unit of group 2 is 1200L/min, and the water flow V1 of the cooling unit of group 1 is 1500L/min.

The remaining steps and parameters were the same as in example 1.

Examples 1 to 11:

the second step is that: the water flow V3 of the cooling unit of group 3 is 6000L/min, the water flow V3 of the cooling unit of group 2 is 7200L/min, and the water flow V1 of the cooling unit of group 1 is 12000L/min.

The remaining steps and parameters were the same as in example 1.

Examples 1 to 12:

the second step is that: the water flow V3 of the 3 rd group of cooling units is 500L/min, the water flow V3 of the 2 nd group of cooling units is 600L/min, and the water flow V1 of the 1 st group of cooling units is 1000L/min.

The remaining steps and parameters were the same as in example 1.

As can be seen from comparative analysis of examples 1-1,1-9,1-10,1-11 and 1-12, the supersaturated solid solution structure can be obtained when the water flow rates of the 3 sets of cooling units of the crystallizer are within the range determined by the technical principles disclosed herein. When the water flow is too high (as in examples 1-11), the metal is directly solidified on the inner wall of the crystallizer due to too strong cooling, so that the metal is stuck and can not be normally extracted. When the water flow is too low (as in examples 1-12), the initial blank cannot be guaranteed to be in a solid solution state due to insufficient cooling, and part of Ag is precipitated in advance, so that the strength and the conductivity are low.

Examples 1 to 13:

the second step is that: the water flow V3 of the group 3 cooling unit is 2000L/min, the water flow V3 of the group 2 cooling unit is 2000L/min, and the water flow V1 of the group 1 cooling unit is 2000L/min.

The remaining steps and parameters were the same as in example 1-1.

As can be seen from comparative analysis of examples 1 and 1 to 13, when the water flow rates of the 3 sets of cooling units of the crystallizer are not set according to the ratio disclosed in the present invention, a reasonable cooling gradient cannot be formed in the 3 sets of cooling units, which results in severe wear of the inner wall of the crystallizer and a reduction of the service life by 50%.

Examples 1 to 14:

the second step is that: the primary blank spraying adopts the conventional small hole spraying, 90 nozzles are arranged, the nozzle interval is 30mm, the distance between the nozzle and the blank surface is 60mm, and the water pressure is 0.3 MPa.

The remaining steps and parameters were the same as in example 1-1.

As can be seen from comparative analysis of examples 1-1 and 1-14, if a strong cooling method is not employed when the initial billet is continuously drawn, for example, the conventional small-hole spraying used in examples 1-14 and the water pressure, hole pitch, etc. are not reasonable, partial desolvation of the solid solution is easily caused, the strength is low, and the precipitation kinetics is weak.

Examples 1 to 15:

the first step is as follows: and (4) melting the ingredients. Proportioning according to the alloy components of Cu-0.5 wt.% Cr-0.1 wt.% Zr, pouring into a melting furnace for melting by weight, sampling, detecting and analyzing the oxygen content and the alloy element content, supplementing materials according to the analysis result, fully deoxidizing to be within 10ppm, and introducing the melt into a holding furnace through a guide groove in the melting furnace.

The second step is that: and (4) horizontally continuously casting. Carrying out horizontal continuous casting below the side of the heat preservation furnace, horizontally arranging and installing 4 crystallizers with the interval of 200mm below the side of the heat preservation furnace, and arranging the crystallizers below the side of the heat preservation furnace3 groups of independent cooling units are arranged along the primary blank leading-out direction, and the 1 st group of cooling units is closest to the holding furnace. The temperature of the water inlet is lower than 20 ℃ by adopting a reverse cooling mode. The water flow V3 of the cooling unit of the 3 rd group is 50L/min, the water flow V2 of the cooling unit of the 2 nd group is 60L/min, the water flow V1 of the cooling unit of the 1 st group is 75L/min, electromagnetic induction coils are arranged on the outer walls of water cooling jackets of the cooling units of the 1 st and the 2 nd groups of the crystallizer to realize electromagnetic stirring, the electromagnetic stirring mode is rotary stirring, and the current frequency is 2 Hz. The sectional area of the primary blank is 50mm²The drawing speed was 100 mm/min. And (3) carrying out water curtain spraying within the range of 1000mm outwards from the outlet of the crystallizer, and arranging 30 atomizing nozzles, wherein the interval between the atomizing nozzles is 20mm, the distance between the nozzles and the surface of the blank is 50mm, and the water pressure is 0.5 MPa.

Fig. 12 shows a primary bar obtained by the horizontal continuous casting of this example. The metallographic structure pictures of fig. 13 and 14 show no distinct precipitated phases inside the grains. The XRD pattern of fig. 15 has only diffraction peaks of copper, and no diffraction peaks of the second phase are observed. The diffraction peak is shifted from the standard copper diffraction peak, which shows that the chromium zirconium element of the obtained primary blank is dissolved in the copper crystal lattice in a solid way.

Examples 1 to 16:

the first step is as follows: and (4) melting the ingredients. The alloy composition was Cu-1 wt.% Cr-0.15 wt.% Zr.

The remaining steps and parameters were the same as in examples 1-15.

Similar to examples 1-15, the XRD patterns of the as-cast primary ingots showed a supersaturated solid solution structure.

Examples 1 to 17:

the first step is as follows: and (4) melting the ingredients. The alloy composition was Cu-0.5 wt.% Cr-0.1 wt.% Zr-0.05 wt.% Si.

The remaining steps and parameters were the same as in examples 1-15.

Examples 1 to 18:

the first step is as follows: and (4) melting the ingredients. The alloy composition was Cu-0.5 wt.% Cr-0.1 wt.% Zr-0.03 wt.% Mg.

The remaining steps and parameters were the same as in examples 1-15.

The results of comparative analysis of examples 1-15 to 1-18 show that the horizontal continuous casting method of the present invention has good applicability to typical ternary copper-chromium-zirconium alloys and alloys that are further microalloyed on the basis of copper-chromium-zirconium.

Examples 1 to 19:

the second step is that: and (4) horizontally continuously casting. 2 crystallizers are used at intervals of 400mm, the water flow V3 of the cooling unit in the 3 rd group is 500L/min, the water flow V2 of the cooling unit in the 2 nd group is 600L/min, the water flow V1 of the cooling unit in the 1 st group is 750L/min, the electromagnetic stirring frequency is 500Hz, the sectional area of the primary billet is 1000mm²The leading-out speed is 100mm/min, 90 atomizing nozzles are arranged, the nozzle interval is 10mm, the distance between the nozzles and the surface of the blank is 10mm, and the water pressure is 0.8 MPa.

The remaining steps and parameters were the same as in examples 1-15.

The XRD pattern of the as-cast primary ingot showed a supersaturated solid solution structure.

Examples 1 to 20:

the first step is as follows: 3 crystallizers are used at intervals of 300mm, the water flow V3 of the cooling unit in the 3 rd group is 100L/min, the water flow V2 of the cooling unit in the 2 nd group is 120L/min, the water flow V1 of the cooling unit in the 1 st group is 150L/min, the electromagnetic stirring frequency is 50Hz, the sectional area of the bloom is 200mm²The extraction speed is 50mm/min,

the remaining steps and parameters were the same as in examples 1-15.

Examples 1 to 21:

the second step is that: and (4) horizontally continuously casting. The electromagnetic stirring frequency is 1Hz, the extraction speed is 2mm/min, and the water pressure is 0.2 MPa.

The remaining steps and parameters were the same as in examples 1-15.

By comparing examples 1-15 and 1-21, it is known that if the electromagnetic stirring frequency is low and the cooling water pressure is low, the melt of the copper chromium zirconium plate strip cannot be stirred sufficiently, fine isometric crystals cannot be formed, a part of Ag atoms are precipitated from a supersaturated solid solution in advance, and develop into a coarse primary phase (fig. 22), so that the alloy strength is weakened, and meanwhile, the subsequent precipitation is insufficient, and the alloy conductivity is damaged.

Examples 1 to 22:

the second step is that: and (4) horizontally continuously casting. The extraction speed is 400mm/min, and the water pressure is 1.0 MPa.

The remaining steps and parameters were the same as in examples 1-15.

Comparing examples 1 to 15 and 1 to 22, it is understood that if the initial billet with a smaller cross section is cooled by strong spray at a high extraction speed, the cooling effect is enhanced and the solid solution is more sufficient, but the solidification is too fast to cause the phenomenon of billet breakage (fig. 23), and the continuity of production is greatly impaired.

As can be seen from comparison of examples 1 to 15, 1 to 21 and 1 to 22, the high-efficiency and high-quality copper-chromium-zirconium primary blank can be obtained by reasonably matching the process parameters such as the extraction sectional area, the extraction speed, the cooling water pressure, the electromagnetic stirring frequency and the like.

Example 1:

The second step is that: horizontal continuous casting: the method comprises the following steps of carrying out horizontal continuous casting below the side of a heat preservation furnace, horizontally arranging 2 crystallizers with the interval of 400mm below the side of the heat preservation furnace, arranging 3 groups of independent cooling units along the primary blank leading-out direction of the crystallizers, and enabling the 1 st group of cooling units to be closest to the heat preservation furnace. The temperature of the water inlet is lower than 20 ℃ by adopting a reverse cooling mode. The water flow V3 of the 3 rd group of cooling units is 2000L/min, the water flow V2 of the 2 nd group of cooling units is 2400L/min, the water flow V1 of the 1 st group of cooling units is 3000L/min, electromagnetic induction coils are arranged on the outer walls of water cooling jackets of the 1 st and 2 nd group of cooling units of the crystallizer to realize electromagnetic stirring, the electromagnetic stirring mode is rotary stirring, and the current frequency is 500 Hz. The sectional area of the primary blank is 2000mm²The drawing speed was 100 mm/min. At the outlet of the crystallizerAnd (3) carrying out water curtain spraying within the range of 1000mm outwards, and arranging 90 atomizing nozzles, wherein the interval between the atomizing nozzles is 10mm, the distance between the nozzles and the surface of the blank is 10mm, and the water pressure is 0.8 MPa.

The third step: continuous extrusion: the extrusion die, which was a wrought superalloy prepared in example 0, was preheated to 500 deg.C, as shown in FIG. 26. The surface oxidation defect layer of the horizontal continuous casting primary blank is removed by a peeling machine, and then the horizontal continuous casting primary blank is quickly preheated to 700 ℃ by an online induction device and then enters a die cavity for extrusion. The rotating speed of the extrusion wheel is 3rpm, the extrusion ratio is 3, and the extrusion gap is controlled to be 0.6 mm. And (3) spraying high-strength cooling water to the blank at the outlet of the extrusion die, and arranging 100 atomizing nozzles, wherein the interval between the atomizing nozzles is 10mm, the distance between the nozzles and the surface of the blank is 10mm, and the water pressure is 0.8 MPa.

The fourth step: cold drawing: and (3) performing cold drawing on the extruded blank according to the product requirement, wherein the pass deformation of the cold drawing is 5%, and the accumulated deformation is 50%.

The fifth step: aging heat treatment: and coiling the cold-processed blank, placing the coiled blank in a bell-type heating furnace, and carrying out aging heat treatment. The blank is placed in the lining, the lining is covered by hoisting after the furnace body reaches a preset temperature, the blank is heated rapidly, and the furnace body is hoisted away by a crane after the designed heat preservation time is reached, so that the blank is cooled rapidly. Reducing atmosphere is introduced in the whole heat treatment process to avoid oxidation. The aging temperature and time of the product are determined by the following principles: taking a plurality of groups of blank samples, and respectively annealing at 300, 350, 400, 450, 500, 550 and 600 ℃ for 0.1, 0.5, 1, 2, 4, 8, 16, 24, 48 and 99.6 hours; the Vickers hardness (unit HV) and the conductivity (unit% IACS) of a sample are tested, the product of the hardness value and the conductivity value is calculated, the test temperature of the sample with the largest product is taken as the annealing temperature of the product, the test time of the sample with the largest product is taken, 0.4h is additionally added to the test time of the sample with the largest product to be taken as the heat preservation time of the product, and the result shows that the sample has the largest product value when being annealed and heat preserved for 1h at 400 ℃, the product heat preservation time is taken as 400 ℃, and the product heat preservation time is taken as 1.4 h.

And a sixth step: the vickers hardness of the obtained product was measured by a vickers hardness tester, and the conductivity of the product was measured by an eddy current conductivity meter, and the results are shown in table 2.

It can be seen from fig. 1 and 4 that nano precipitated phases and high-density dislocations are generated in a dispersed manner in the copper alloy of the present embodiment, the fine isometric crystal structure of the as-cast state can be seen from fig. 2, the XRD of the as-cast state primary blank can be seen from fig. 3 without detecting the second phase (Ag), and the XRD of the aged product can detect the obvious diffraction peak of the second phase, which proves the characteristics of the supersaturated solid solution structure of the as-cast state primary blank and the precipitated phase strengthening structure of the aged product. It can be seen from FIGS. 5 and 6 that the recrystallized structure obtained in the squeezed state and the interior of the grains have no second phase, indicating that the supersaturated solid solution characteristics are still maintained.

Example 2:

The third step: continuous extrusion: the rotating speed of the extrusion wheel is 8rpm, the extrusion ratio is 8, and the extrusion gap is 2 mm. 25 atomizing nozzles are arranged, the interval between the atomizing nozzles is 20mm, the distance between the nozzles and the surface of the blank is 50mm, and the water pressure is 0.5 MPa.

The fourth step: cold processing: the pass deformation was 10%, and the cumulative deformation was 99%.

The remaining steps and parameters were the same as in example 1.

Similar to example 1, the XRD pattern of the as-cast primary billet shows that it has a supersaturated solid solution structure, and TEM photographs of the billet after extrusion cooling show that no nano-precipitated phase is generated inside the extruded billet, indicating that the supersaturated solid solution characteristics are still maintained.

Example 3:

The third step: continuous extrusion: preheating an extrusion die to 600 ℃, and quickly preheating an initial blank to 700 ℃.

The remaining steps and parameters were the same as in example 1.

Wherein, the XRD pattern of the as-cast primary billet shows that the billet has a supersaturated solid solution structure, and the TEM picture of the billet after extrusion cooling shows that no nano precipitated phase is generated in the extruded state, which indicates that the supersaturated solid solution characteristics are still maintained.

Example 4:

The third step: continuous extrusion: the rotating speed of the extrusion wheel is 8rpm, the extrusion ratio is 8, and the extrusion gap is 2 mm. Preheating an extrusion die to 600 ℃, and quickly preheating an initial blank to 700 ℃.

The remaining steps and parameters were the same as in example 1.

The XRD pattern of the as-cast primary blank shows that the blank has a supersaturated solid solution structure, and a TEM picture of the blank after extrusion cooling shows that no nano precipitated phase is generated in the extruded interior, which indicates that the supersaturated solid solution characteristics are still maintained. It can be seen from fig. 4 that the copper alloy produced in this example generates dispersed nano precipitated phases and high density dislocations therein.

Example 5:

The third step: continuous extrusion: preheating an extrusion die to 600 ℃, and quickly preheating an initial blank to 750 ℃.

The remaining steps and parameters were the same as in example 1.

The XRD pattern of the as-cast primary billet shows that the billet has a supersaturated solid solution structure, and a TEM picture of the billet after extrusion cooling shows that no nano precipitated phase is generated in the extruded inner part, which indicates that the supersaturated solid solution characteristics are still maintained.

Example 6:

The third step: continuous extrusion: preheating an extrusion die to 550 ℃, and quickly preheating a primary blank to 700 ℃.

The remaining steps and parameters were the same as in example 1.

The results of examples 1 to 6 show that the method has good applicability to common Cu-X binary alloys (such as Cu-Ag) and Cu-X-Y ternary alloys (such as Cu-Fe-P, Cu-Cr-Zr and Cu-Ni-Si). The prepared copper alloy has a fine and uniform nano precipitated phase structure and high-strength and high-conductivity characteristics, the comprehensive performance of the copper alloy is close to or better than that of products obtained by other technologies, and the copper alloy has high yield and productivity and is very suitable for industrial large-scale manufacturing.

Example 7:

The third step: continuous extrusion: the rotating speed of the extrusion wheel is 8rpm, the extrusion ratio is 8, and the extrusion gap is 2 mm. The interval of the atomizing nozzles is 20mm, the distance between the nozzles and the surface of the blank is 50mm, and the water pressure is 0.5 MPa.

The remaining steps and parameters were the same as in example 1.

Comparing examples 1 and 7, it is known that if the initial billet with a small cross-sectional area is cooled by a strong spray at a high extraction rate, the cooling effect is enhanced, the solid solution is more sufficient, but the solidification is too fast, and the billet breaking phenomenon (fig. 7) occurs, and the production continuity is greatly impaired.

Example 8:

The remaining steps and parameters were the same as in example 1.

Comparing examples 1 and 8, it is understood that if the drawing rate is low, the electromagnetic stirring frequency is low, and the cooling water pressure is low, the copper alloy melt is insufficiently stirred, and fine equiaxed crystals cannot be formed, and a part of Ag atoms are precipitated from the supersaturated solid solution in advance, and develop into a coarse primary phase (fig. 8). Weakening the strength of the alloy and simultaneously causing insufficient subsequent precipitation and damaging the conductivity of the alloy. Therefore, the technological parameters such as the extraction sectional area, the extraction speed, the cooling water pressure, the electromagnetic stirring frequency and the like must be reasonably matched.

Example 9:

the third step: the material of the die used for continuous extrusion is Cr12MoV die steel.

The remaining steps and parameters were the same as in example 1.

As can be seen from comparing examples 1 and 9, if the extrusion die uses a general die steel, the die life is very short, the die needs to be frequently replaced, the production rhythm is seriously damaged, the productivity is reduced, and the waste is increased. Figure 9 shows a typical die steel bulkhead component being scrapped.

Example 10:

the third step: the induction preheating temperature of the continuous extrusion primary blank is 500 ℃.

The remaining steps and parameters were the same as in example 1.

Example 11:

the third step: the interval of the spraying water-cooling atomizing nozzles at the continuous extrusion outlet is 30mm, 20 nozzles are arranged, the distance between the nozzles and the surface of the blank is 80mm, and the water pressure is 0.2 MPa.

The remaining steps and parameters were the same as in example 1.

It is understood from comparative examples 1, 10 and 11 that the lower preheating temperature of the preform or the insufficient cooling effect of the extrusion outlet preform in the continuous extrusion process resulted in a decrease in the overall strength and conductivity of the product due to the early desolvation decomposition of the supersaturated solid solution, resulting in a coarse and uneven precipitated phase (fig. 10).

Example 12:

the third step: the continuous extrusion die was preheated to 425 ℃.

The remaining steps and parameters were the same as in example 1.

It can be seen from comparison of examples 1 and 12 that insufficient preheating of the die in the continuous extrusion process results in less than 120HV & 95% IACS for the product properties produced during the initial stages of extrusion. The reason for this is that the temperature of the cavity is low at the initial stage of extrusion, and the supersaturated solid solution is desolventized and decomposed in advance. And the extrusion stress is too large, resulting in a reduction in the life of the die.

Example 13:

the third step: the continuous extrusion ratio was 1.

The remaining steps and parameters were the same as in example 1.

It can be seen from comparing examples 1 and 13 that if the extrusion ratio is too low in the continuous extrusion process, the deformation of the material is insufficient, and the material cannot be effectively reinforced, so that the strength of the product is low. And the extrusion temperature is slightly lower, the supersaturated solid solution is partially desolventized and decomposed in advance, and the conductivity is slightly damaged.

Example 14:

the third step: the continuous extrusion ratio was 9.

The remaining steps and parameters were the same as in example 1.

It can be seen from comparing examples 1 and 14 that if the extrusion ratio in the continuous extrusion process is too high, the product strength can be further improved, but the occurrence of the stuffiness and the die breakage is repeated several times, and the life and productivity of the equipment are seriously deteriorated.

Example 15:

the fourth step: the cumulative cold work deformation was 30%.

The remaining steps and parameters were the same as in example 1.

It is understood from comparative examples 1 and 15 that when the cumulative cold working strain is small, the effect of work hardening on the copper alloy is weak, the dislocation density is not high, and the precipitation kinetics is weak. Not only the hardness is low, but also the conductivity is low.

Example 16:

the fifth step: aging heat treatment: the sample is annealed and kept at 400 ℃ for 1 h.

The remaining steps and parameters were the same as in example 1.

It can be seen from comparison of examples 1 and 16 that if the aging annealing holding time is selected without adding 0.4h required by the present invention, the alloy elements cannot be sufficiently aged and precipitated, and the electrical conductivity is low. The additional 0.4h is a rule which is made by carefully considering the difference between the temperature-rise and temperature-average characteristics during charging of the large furnace and the small sample.

Example 17:

The remaining steps and parameters were the same as in example 1.

Example 18:

The remaining steps and parameters were the same as in example 1.

Example 19:

The remaining steps and parameters were the same as in example 1.

Example 20:

The remaining steps and parameters were the same as in example 1.

It can be seen from comparative analyses of examples 1,17,18,19 and 20 that good high-strength and high-conductivity copper alloys can be obtained when the water flow rates of the 3 sets of cooling units of the crystallizer are within the range determined by the technical principles disclosed in the present invention. When the water flow is too high (as in example 19), the metal is directly solidified on the inner wall of the crystallizer due to too strong cooling, so that the metal is blocked and can not be normally extracted. When the water flow is too low (as in example 20), the initial blank cannot be guaranteed to be in a solid solution state due to insufficient cooling, and part of Ag is precipitated in advance, so that the strength and the conductivity are low.

Example 21:

The remaining steps and parameters were the same as in example 1.

It can be seen from comparative analysis of examples 1 and 21 that when the water flow rates of the 3 sets of cooling units of the crystallizer are not set according to the proportion disclosed in the present invention, a reasonable cooling gradient cannot be formed in the 3 sets of cooling units, which results in severe wear of the inner wall of the crystallizer and a reduction of the service life by 50%.

Example 22:

the third step: the continuous extrusion outlet was water cooled with a water bath immersion rather than an atomized spray.

The remaining steps and parameters were the same as in example 1.

As can be seen from comparative analysis of examples 1 and 22, if a strong cooling method is not employed after the continuous extrusion, for example, the conventional water bath used in example 22 is immersed for cooling, it is easy to cause partial desolvation of the solid solution, and the strength is low and the precipitation kinetics is weak. As shown in FIG. 11, the TEM observation of the samples of example 22 after continuous extrusion cooling shows that Ag precipitate phases have appeared in the structure, indicating that the solid solution has been partially desolventized.

Example 23:

The remaining steps and parameters were the same as in example 1.

It is understood from comparative analysis of examples 1 and 23 that, if a strong cooling method is not employed when the initial billet is continuously drawn out, for example, the conventional small hole spray used in example 23, and the water pressure, hole pitch, etc. are not reasonable, partial desolvation of the solid solution is likely to occur, the strength is low, and the precipitation kinetics is weak.

Example 24:

the second step is that: high-temperature solid solution is carried out after conventional horizontal continuous casting. The temperature of the holding furnace is controlled at 1250 ℃, the crystallizer adopts a conventional copper inner wall steel sleeve water-cooling crystallizer which only comprises a water cooling unit, the flow rate of the used cooling water is selected from conventional parameters of 50L/min, the traction speed is 10mm/s, and the copper alloy rod is obtained by casting. Carrying out solution treatment on a copper alloy rod produced by horizontal continuous casting, wherein the solution treatment temperature is 900 ℃, the heating mode selects on-line induction heating, the treatment time is 40min, quenching adopts conventional small-hole spraying, 90 nozzles are arranged, the interval between the nozzles is 30mm, the distance between the nozzles and the surface of a blank is 60mm, and the water pressure is 0.3 MPa.

The remaining steps and parameters were the same as in example 1.

As can be seen from comparison of examples 1 and 24, the horizontal continuous casting of the present invention has significantly improved hardness and conductivity compared to the conventional horizontal continuous casting and high temperature solution technology, and does not require a high temperature solution step with extremely high energy consumption.

TABLE 2 summary of product Performance, yield, and Capacity for the examples

Statistics of the productivity of a set of horizontal continuous casting and continuous extrusion production line

Example 25:

The second step is that: and (4) horizontally continuously casting. The method comprises the following steps of carrying out horizontal continuous casting below the side of a heat preservation furnace, horizontally arranging 4 crystallizers with the interval of 200mm below the side of the heat preservation furnace, arranging 3 groups of independent cooling units along the primary blank leading-out direction of the crystallizers, and enabling the 1 st group of cooling units to be closest to the heat preservation furnace. The temperature of the water inlet is lower than 20 ℃ by adopting a reverse cooling mode. The water flow V3 of the cooling unit of the 3 rd group is 50L/min, the water flow V2 of the cooling unit of the 2 nd group is 60L/min, the water flow V1 of the cooling unit of the 1 st group is 75L/min, electromagnetic induction coils are arranged on the outer walls of water cooling jackets of the cooling units of the 1 st and the 2 nd groups of the crystallizer to realize electromagnetic stirring, the electromagnetic stirring mode is rotary stirring, and the current frequency is 2 Hz. The sectional area of the primary blank is 50mm²The drawing speed was 100 mm/min. And (3) carrying out water curtain spraying within the range of 1000mm outwards from the outlet of the crystallizer, and arranging 30 atomizing nozzles, wherein the interval between the atomizing nozzles is 20mm, the distance between the nozzles and the surface of the blank is 50mm, and the water pressure is 0.5 MPa.

The third step: and (4) continuously extruding. The extrusion die, which was made of the forged high temperature nickel-based alloy prepared in example 0, was preheated to 500 c, and the die structure design is shown in fig. 25. The surface oxidation defect layer of the horizontal continuous casting primary blank is removed by a peeling machine, and then the horizontal continuous casting primary blank is quickly preheated to 800 ℃ by an online induction device and then enters a die cavity for extrusion. The rotating speed of the extrusion wheel is 8rpm, the extrusion ratio is 8, and the extrusion gap is controlled at 2 mm. And (3) spraying high-strength cooling water to the blank at the outlet of the plate-type die, and arranging 20 atomizing nozzles, wherein the interval between the atomizing nozzles is 20mm, the distance between the nozzles and the surface of the blank is 50mm, and the water pressure is 0.5 MPa.

The fourth step: and (5) cold rolling. And (3) cold rolling the extruded blank according to the product requirements, wherein the pass deformation of the cold rolling is 5%, and the accumulated deformation is 99%.

The fifth step: and (4) aging heat treatment. And coiling the cold-rolled blank, placing the coiled blank in a bell-type heating furnace, and carrying out aging heat treatment. The blank is placed in the lining, the lining is covered by hoisting after the furnace body reaches a preset temperature, the blank is heated rapidly, and the furnace body is hoisted away by a crane after the designed heat preservation time is reached, so that the blank is cooled rapidly. Reducing atmosphere is introduced in the whole heat treatment process to avoid oxidation. The aging temperature and time of the product are determined by the following principles: taking a plurality of groups of blank samples, and respectively annealing at 300, 350, 400, 450, 500, 550 and 600 ℃ for 0.1, 0.5, 1, 2, 4, 8, 16, 24, 48 and 99.6 hours; the Vickers hardness (unit HV) and the conductivity (unit% IACS) of a sample are tested, the product of the hardness value and the conductivity value is calculated, the test temperature of the sample with the largest product is taken as the annealing temperature of the product, the test time of the sample with the largest product is taken, 0.4h is additionally added to the test time of the sample with the largest product to be taken as the heat preservation time of the product, and the result shows that the sample has the largest product value when being annealed and heat preserved for 1h at 500 ℃, the product heat preservation time is taken as 500 ℃, and the product heat preservation time is taken as 1.4 h.

And a sixth step: the Vickers hardness of the obtained product was measured using a Vickers hardness tester, and the conductivity of the product was measured using an eddy current conductivity meter, and the results are shown in Table 3.

Fig. 12 shows a primary bar obtained by the horizontal continuous casting of this example. The metallographic structure pictures of fig. 13 and 14 show no distinct precipitated phases inside the grains. The XRD pattern of fig. 15 has only diffraction peaks of copper, and no diffraction peaks of the second phase are observed. The diffraction peak is shifted from the standard copper diffraction peak, which shows that the chromium zirconium element of the obtained primary blank is dissolved in the copper crystal lattice in a solid way. Fig. 16 shows the equiaxed texture of the sample after continuous extrusion. The TEM photograph of the billet after extrusion cooling of fig. 17 shows that no nano precipitated phase is generated inside the extruded state, indicating that the supersaturated solid solution characteristics are still maintained. Fig. 18 shows the presence of high density dislocation tangles inside the cold rolled samples. FIG. 19 shows the appearance of a high density precipitate phase inside the aged samples. Fig. 20 shows a lattice fringe image of the nanophase precipitates using high resolution TEM.

Example 26:

The remaining steps and parameters were the same as in example 25.

Similar to example 25, the XRD pattern of the as-cast primary billet showed a supersaturated solid solution structure, and TEM photographs of the billet after extrusion cooling showed no nano-precipitates within the as-extruded billet, indicating that the supersaturated solid solution characteristics were maintained.

Example 27:

The remaining steps and parameters were the same as in example 25.

Example 28:

The remaining steps and parameters were the same as in example 25.

The results of the comparative analysis of the examples 25-28 show that the method has good applicability to typical copper-chromium-zirconium ternary alloys and alloys obtained by further microalloying on the basis of copper, chromium and zirconium. The prepared copper chromium zirconium plate strip has a fine and uniform nano precipitated phase structure and high-strength and high-conductivity characteristics, the comprehensive performance of the copper chromium zirconium plate strip is close to or better than that of products obtained by other technologies, and the copper chromium zirconium plate strip has high yield and is very suitable for industrial large-scale manufacturing.

Example 29:

The third step: and (4) continuously extruding. The rotating speed of the extrusion wheel is 3rpm, the extrusion ratio is 3, and the extrusion gap is 0.6 mm. 50 atomizing nozzles are arranged, the interval between the atomizing nozzles is 10mm, the distance between the nozzles and the surface of the blank is 10mm, and the water pressure is 0.8 MPa.

The remaining steps and parameters were the same as in example 25.

Example 30:

the third step: and (4) continuously extruding. The rotating speed of the extrusion wheel is 8rpm, the extrusion ratio is 8, and the extrusion gap is 2 mm. Preheating an extrusion die to 600 ℃, and quickly preheating an initial blank to 700 ℃.

The remaining steps and parameters were the same as in example 25.

Example 31:

the third step: and (4) continuously extruding. Preheating the extrusion die to 550 ℃ and quickly preheating the primary blank to 750 ℃.

The remaining steps and parameters were the same as in example 25.

Example 32:

the fourth step: the cumulative cold rolling deformation was 50%.

The remaining steps and parameters were the same as in example 25.

Example 33:

The remaining steps and parameters were the same as in example 25.

By comparing examples 25 and 33, it is understood that when the electromagnetic stirring frequency is low and the cooling water pressure is low, the melt of the copper chromium zirconium plate strip is insufficiently stirred, so that fine equiaxed crystals cannot be formed, and a part of Ag atoms are precipitated from the supersaturated solid solution in advance to develop into a coarse primary phase (FIG. 22). Weakening the strength of the alloy and simultaneously causing insufficient subsequent precipitation and damaging the conductivity of the alloy.

Example 34:

The remaining steps and parameters were the same as in example 25.

Comparing examples 25 and 34, it is found that the cooling effect is enhanced and the solid solution is more sufficient when the initial billet with a small cross-sectional area is cooled by a strong spray in combination with a high drawing speed, but the solidification is too fast to cause a billet breaking phenomenon (fig. 23), and the production continuity is greatly impaired.

It can be seen from comparison of examples 25, 33 and 34 that the copper-chromium-zirconium primary blank with high efficiency and high quality can be obtained by reasonably matching the process parameters such as the extraction cross-sectional area, the extraction speed, the cooling water pressure, the electromagnetic stirring frequency and the like.

Example 35:

the third step: the induction preheating temperature of the continuous extrusion primary blank is 600 ℃.

The remaining steps and parameters were the same as in example 25.

Example 36:

the third step: the interval of the spraying water-cooling atomizing nozzles at the continuous extrusion outlet is 30mm, the distance between the nozzles and the surface of the blank is 80mm, and the water pressure is 0.2 MPa.

The remaining steps and parameters were the same as in example 25.

It is understood from comparative examples 25, 35 and 36 that the lower preheating temperature of the preform or insufficient cooling effect of the extrusion outlet preform in the continuous extrusion process resulted in a decrease in the combination of strength and conductivity of the product due to the early desolvation decomposition of the supersaturated solid solution to produce a coarse and uneven precipitated phase (FIG. 24).

Example 37:

the third step: the continuous extrusion die was preheated to 450 ℃.

The remaining steps and parameters were the same as in example 25.

It can be seen from comparative examples 25 and 37 that insufficient preheating of the die in the continuous extrusion process results in a product performance of less than 200HV & 84% IACS at the initial stage of extrusion. The reason for this is that the supersaturated solid solution is desolventized and decomposed in advance due to the low temperature of the cavity at the initial stage of extrusion. And the extrusion stress is too large, resulting in a reduction in the life of the die.

Example 38:

the third step: the continuous extrusion ratio was 2.

The remaining steps and parameters were the same as in example 25.

It can be seen from the comparison of examples 25 and 38 that if the extrusion ratio is too low in the continuous extrusion process, the deformation of the material is insufficient, and the material cannot be effectively reinforced, so that the strength of the product is low. And the extrusion temperature is slightly lower, the supersaturated solid solution is partially desolventized and decomposed in advance, and the conductivity is slightly damaged.

Example 39:

the third step: the continuous extrusion ratio was 10.

The remaining steps and parameters were the same as in example 25.

It can be seen from comparison of examples 25 and 39 that if the extrusion ratio in the continuous extrusion process is too high, the product strength can be further improved, but the occurrence of the stuffiness and the die cracking several times seriously deteriorates the equipment life and the productivity.

Example 40:

the fourth step: the cumulative cold rolling deformation was 40%.

The remaining steps and parameters were the same as in example 25.

It is understood from comparative examples 25 and 40 that when the cumulative cold rolling strain is small, the work hardening effect on the copper chromium zirconium plate strip is weak, the dislocation density is not high, and the precipitation kinetics is weak. Not only the hardness is low, but also the conductivity is low.

Example 41:

the fifth step: aging heat treatment: the sample is annealed and kept at 500 ℃ for 1 h.

The remaining steps and parameters were the same as in example 25.

It is understood from comparative examples 25 and 41 that if the aging annealing holding time is selected without adding 0.4h required by the present invention, the alloy elements are not yet sufficiently aged and precipitated, and the electric conductivity is low. The additional 0.4h is a rule which is made by carefully considering the difference between the temperature-rise and temperature-average characteristics during charging of the large furnace and the small sample.

Example 42:

the second step is that: high-temperature solid solution is carried out after conventional horizontal continuous casting. The temperature of the holding furnace is controlled at 1250 ℃, the crystallizer adopts a conventional copper inner wall steel sleeve water-cooling crystallizer which only comprises one cooling unit, the flow rate of the used cooling water is selected from conventional parameters of 50L/min, the traction speed is 10mm/s, and the copper alloy rod is obtained by casting. Carrying out solution treatment on a copper alloy rod produced by horizontal continuous casting, wherein the solution treatment temperature is 900 ℃, the heating mode selects on-line induction heating, the treatment time is 40min, quenching adopts conventional small-hole spraying, 90 nozzles are arranged, the interval between the nozzles is 30mm, the distance between the nozzles and the surface of a blank is 60mm, and the water pressure is 0.3 MPa.

The remaining steps and parameters were the same as in example 25.

As can be seen from comparison of examples 25 and 42, the horizontal continuous casting according to the present invention has significantly improved hardness and conductivity compared to the conventional horizontal continuous casting plus high-temperature solution, and does not require a high-temperature solution step with extremely high energy consumption.

TABLE 3 summary of product Properties and yield in the examples

Claims

1. A horizontal continuous casting method of copper alloy is to horizontally continuously cast a copper alloy melt in a holding furnace below the side of the holding furnace, and is characterized in that: at least one multi-path water-cooling crystallizer is arranged below the side of the heat preservation furnace, 3 groups of independent cooling units are sequentially arranged on the multi-path water-cooling crystallizer along the leading-out direction of the primary blank, multi-path water inlet and multi-path water outlet are realized, a reverse cooling mode is adopted, and the cooling unit of the 1 st group is closest to the heat preservation furnace; the temperature of the water inlet of each group of cooling units is lower than 20 ℃, and the temperature gradient of 3 groups of cooling units is controlled by the following method: the water flow V3 and the sectional area S of the initial blank of the 3 rd group cooling unit are satisfied

The water flow rate of the group 2 cooling unit V2 and the water flow rate of the group 1 cooling unit V1 are determined according to the principle of V1: V2: V3=1.5:1.2: 1; arranging electromagnetic induction coils on the outer walls of the water cooling jackets of the 1 st group and the 2 nd group of cooling units of the multi-path water-cooled crystallizer to realize electromagnetic stirring, wherein the electromagnetic stirring mode is rotary stirring, and the current frequency is set to be 2-500 Hz; controlling the sectional area S of the primary blank to be 50-2000 mm²The drawing speed v and the sectional area of the blank are satisfied

(ii) a The method is characterized in that a water curtain spraying cooling device is arranged in the range of 1000mm outwards from the outlet of the multi-path water-cooled crystallizer to cool a primary blank, atomizing nozzles are adopted by the spraying device, the interval between the nozzles is 10-20 mm, the number of the nozzles is set according to the size of the blank, the distance between the nozzles and the surface of the blank is 10-50 mm, and the water pressure is 0.5-0.8 MPa, so that the cast-state primary blank with alloy elements in a supersaturated solid solution state is obtained.

2. The horizontal continuous casting method of a copper alloy according to claim 1, wherein: one set of horizontal continuous casting system collocation 2~4 multichannel water-cooled crystallizer realize 2~4 continuous extraction of initial blank, and the mode of arranging of multichannel water-cooled crystallizer is arranged for being a word at this moment, and the interval is 200~400mm, and independent water-cooling and electromagnetic means are all disposed to every set of multichannel water-cooled crystallizer.

3. The horizontal continuous casting method of a copper alloy according to claim 1, wherein the horizontal continuous casting method of a copper alloy is performed according to the steps of:

(2) horizontal continuous casting: carrying out horizontal continuous casting below the side of the heat preservation furnace, installing at least one multi-path water-cooled crystallizer below the side of the heat preservation furnace, sequentially arranging 3 groups of independent cooling units along the leading-out direction of the primary blank for realizing multi-path water inlet and multi-path water outlet, and adopting a reverse cooling mode, namely, water inlet at a cold end and water outlet at a hot end, wherein the 1 st group of cooling units is closest to the heat preservation furnace; the temperature of the water inlet of each group of cooling units is lower than 20 ℃, and the temperature gradients of the three groups of cooling units are controlled by the following modes: water flow V3 of group 3 cooling unit and sectional area S of the blank

The water flow rate V2 of the 2 nd group cooling unit and the water flow rate V1 of the 1 st group cooling unit are determined according to the principle of V1: V2: V3=1.5:1.2:1, so that the cooling capacities of the three groups of cooling units with different strengths are matched to form a reasonable temperature gradient; arranging electromagnetic induction coils on the outer walls of water cooling jackets of a 1 st group and a 2 nd group of cooling units of the crystallizer to realize electromagnetic stirring, wherein the electromagnetic stirring mode is rotary stirring, and the current frequency is set to be 2-500 Hz; the sectional area S of the primary blank is 50-2000 mm²The drawing speed v and the sectional area of the blank are in accordance with

Determining the principle of (1); a water curtain spray cooling device is arranged in the range of 1000mm outwards from the outlet of the crystallizer to cool the primary blank, and the spray device adopts an atomizing nozzle instead of a conventional small hole for spraying; the interval of the nozzles is 10-20 mm, the number of the nozzles is set according to the size of the blank, the distance between the nozzles and the surface of the blank is 10-50 mm, and the water pressure is 0.5-0.8 MPa.