CN111593207A - Preparation method of low-cost fine-grain CuCr contact material - Google Patents
Preparation method of low-cost fine-grain CuCr contact material Download PDFInfo
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- CN111593207A CN111593207A CN202010304752.2A CN202010304752A CN111593207A CN 111593207 A CN111593207 A CN 111593207A CN 202010304752 A CN202010304752 A CN 202010304752A CN 111593207 A CN111593207 A CN 111593207A
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- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/16—Remelting metals
- C22B9/18—Electroslag remelting
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- C—CHEMISTRY; METALLURGY
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- H—ELECTRICITY
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- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
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Abstract
The invention discloses a preparation method of a low-cost fine-grain CuCr contact material, which comprises the following steps: (1) cleaning and drying, (2) electrode pressing, (3) charging, (4) electroslag remelting, (5) heat treatment, and (6) machining, the method takes material scraps generated in the production process as raw materials to prepare the electrode, reduces the use cost of the raw materials, simultaneously adopts an electroslag remelting process to remove impurities, and as the end of a consumable electrode is gradually melted, molten metal is gathered into liquid drops, passes through a slag pool, falls into a water-cooled crystallizer, and is rapidly solidified under the action of water cooling, so that Cr particles are refined.
Description
Technical Field
The invention relates to the technical field of contact materials, in particular to a preparation method of a low-cost fine-grain CuCr contact material.
Background
The electric contact material of the vacuum arc extinguish chamber directly plays the functions of breaking and connecting circuits and bearing normal working current or overload current within a certain time, is used as a core component in the arc extinguish chamber, plays an important role in the contact, and is a core material of a vacuum circuit breaker and a vacuum arc extinguish chamber of a medium-high voltage grade transmission and distribution switch. The CuCr contact is the best material used by the currently accepted vacuum circuit breaker, plays a role in closing, bearing and opening current under normal loop conditions in the service process and can close, bear and open current under abnormal loop conditions in a specified time, but in the practical application process, the situation that the requirements cannot be met due to breakdown, fusion welding and the like still exists, although the problem on one aspect can be solved by adopting different preparation processes, the performance of the arc extinguish chamber on the other aspect is often sacrificed, through dozens of years of research and development, experts at home and abroad generally consider that the refinement of Cr particles is beneficial to improving the comprehensive performance of the arc extinguish chamber, and the CuCr contact is an important way for optimizing the vacuum arc extinguish chamber, but has the disadvantage of high manufacturing cost.
In summary, the following defects mainly exist in the current technology:
1. by adopting the vacuum induction melting process, although the raw material cost is lower, Cr particles are thick, and due to low cooling efficiency, enrichment phenomenon exists in the structure, which is unfavorable for the service of the contact;
2. the contact prepared by adopting the powder metallurgy process has the defects of large Cr particles, low tissue density and high raw material cost although the contact is low in cost and uniform in tissue;
3. by adopting the vacuum consumable process, although Cr particles with refined structures can be obtained, the service performance of the contact can be optimized, the requirement on raw materials is higher, so that the manufacturing cost is greatly improved, and due to the process limitation, the current vacuum consumable process has the problem of lower qualification rate for the preparation of the contact with the Cr content of less than 30 percent;
4. although the electroslag remelting process is adopted in the method for preparing the CuCr alloy contact material by self-propagating casting-electroslag remelting of the CN 101067170A at present, the raw materials are CuO, Cr2O3 and Al, and the phenomenon of insufficient aluminothermic reduction may exist when the Al addition amount is insufficient compared with the Al addition amount of the invention.
Disclosure of Invention
Aiming at the problems, the invention provides a preparation method of a low-cost fine-grain CuCr contact material.
The technical scheme of the invention is as follows:
a preparation method of a low-cost fine-grain CuCr contact material comprises the following steps:
(1) cleaning and drying
Soaking and cleaning CuCr leftover bits by adopting cleaning equipment to remove oil stains and impurities on the surface, and then drying to remove water on the surface;
(2) electrode pressing
Mixing CuCr chips with different Cr contents to 1-50% according to the requirement, putting the mixture into a die for pressing, wherein the pressure is 100-300Mpa, and the pressure maintaining time is 2-15min, so that the density is more than 80%, and obtaining the electrode rod;
(3) charging furnace
Putting the prepared electrode bar into an electroslag furnace, connecting the electrode bar with a false electrode of a cathode, and ensuring that the electrode bar and the false electrode are coaxial and vertical; the crystallizer adopts a water-cooling copper mold, the gasket and the electrode are made of the same material, and the thickness is more than 3 mm; the temperature of slag added into the crystallizer before arc striking is not lower than 130 ℃, the arc striking is not easy to happen due to the low temperature, or the arc striking is unstable due to the quick heat dissipation;
(4) electroslag remelting
After the charging is finished, the vacuum system is started, and when the vacuum is pumped to 3 × 10-1A pa grade, switching on a power supply, remelting, leading metal molten drops at the end part of the electrode to fall off under the action of gravity, penetrating through a slag pool and entering a metal molten pool, and leading molten metal to be rapidly solidified under the forced cooling action of a water-cooled crystallizer to form a fine chromium phase, namely a remelting CuCr block;
(5) thermal treatment
Annealing process is adopted to eliminate the ingot casting stress;
(6) machining
And (5) machining according to the drawing requirements.
Further, in the above scheme, in the step (2), two CuCr chips with 5% Cr content and 30% Cr content are mixed for electrode pressing, and the mixture ratio is adjusted to 25% of total Cr content. The CuCr chips with 25% Cr content can also be used as they are.
The raw materials are the leftover bits of CuCr1-CuCr50, such as turning bits and saw dust obtained in the normal processing process of a CuCr product, and the currently required conventional CuCr products mainly comprise CuCr1, CuCr2, CuCr10, CuCr25, CuCr30, CuCr35, CuCr40, CuCr45 and CuCr50, so the leftover bits of CuCr1-CuCr50 can be prepared according to the requirements to smelt the products with the specifications.
Further, in the scheme, CaF is adopted as the electroslag in the electroslag furnace in the step (3)2、Al2O3MgO or CaO, the electroslag generates heat to melt the electrode bar, and has the function of filtering impurities, and the slag must be dried at 800 ℃ under 500-800 ℃ before use, and the baking time is not less than 4 hours, preferably 4-7 hours, so as to remove volatile matters such as water vapor and the like.
Further, in the above scheme, the remelting operation in step (4) is specifically as follows: when a power supply is switched on, the initial voltage is controlled to be 20-85V, the current is controlled to be 1000-5000A, the voltage and the current are controlled in the range of the interval mainly for controlling the melting speed, the melting speed is a main factor influencing the shape of a molten pool and the crystallization speed, when the melting speed is too slow, the cold shut phenomenon is easily caused, simultaneously, impurities are increased, when the melting speed is too fast, crystal grains are easily caused to grow, and meanwhile, the components are easily segregated; when the lower end of the electrode rod glows red heat, argon is filled into the furnace to-0.09 to-0.6 Mpa, then the power is further increased, and the temperature is controlled between 1300 ℃ and 2000 ℃. In principle, the temperature is controlled to be 200 ℃ higher than the melting point of the alloy to be smelted, and the voltage and the current are adjusted according to the temperature.
As a further improvement, in the scheme, the remelting is carried out for 4 times in the step (4).
The electroslag remelting is a method for smelting by using resistance heat generated when current passes through slag as a heat source, the electroslag smelting is essentially an arc-free consumable smelting method, the basic principle of the electroslag remelting process is that liquid slag is injected into a copper water-cooling crystallizer, one end of a consumable electrode is inserted into the slag, current from a short net enters the slag through the consumable electrode, the generated resistance heat heats the slag to high temperature, the end part of the consumable electrode is heated and gradually melted to form metal molten drops, the metal molten drops fall off from the end of the electrode under the action of gravity, and the metal molten drops pass through a slag pool to enter the metal molten pool, and the liquid metal gradually forms ingots under the cooling action of the water-cooling crystallizer.
The vacuum consumable process is independently adopted, so that the Cr particles with refined structures can be obtained, the service performance of the contact can be optimized, the requirement on raw materials is high, the manufacturing cost is greatly improved, and the problem of low qualification rate of the conventional vacuum consumable process for preparing the contact with the Cr content of less than 30 percent is solved due to the process limitation;
however, researches show that better effects can be obtained by combining the electroslag remelting process and the vacuum consumable process, the material performance is greatly improved due to the first electroslag remelting process, the requirements of the contact on raw materials are met by carrying out the vacuum consumable process smelting subsequently, and the preparation qualification rate of the contact with the Cr content of less than 30 percent is also greatly improved. After the electrode bar is subjected to electroslag remelting and 4 times of remelting treatment of a vacuum consumable process, the content of oxygen and nitrogen can be further reduced, the density is further improved, the hardness is further increased, the conductivity is better, and the breaking performance of the contact is improved.
Furthermore, the last 3 remelting times of the 4 remelting times are specifically: putting the first-remelting CuCr block serving as a secondary electrode into a vacuum consumable arc furnace for secondary smelting to obtain a secondary remelting CuCr block, and remelting the secondary remelting CuCr block according to the first remelting operation to obtain a third remelting CuCr block; and then the third-time remelting CuCr block is placed into a vacuum consumable arc furnace to be treated according to the second smelting operation, and the electrode bar after 4 times remelting treatment is obtained.
Further, the specific process parameters of the 2 nd smelting and the 4 th smelting are as follows: the crystallizer adopts a water-cooled copper mold, the specification of the crystallizer is phi 500-phi 600mm, the vacuum degree before melting is less than or equal to 3Pa, the gas leakage rate is less than or equal to 1.5Pa/min, the melting voltage is 45-60V, the melting current is 10-15 KA, the arc stabilizing current adopts direct current of 15-20A, and the cooling time after melting is 0.5-2 h.
Further, in the scheme, the heat treatment temperature in the step (5) is controlled to be between 600 ℃ and 900 ℃, and the heat preservation time is 2-4 h. The effect of removing stress can not be achieved below 600 ℃, the material conductivity is lower, the hardness is higher, the material hardness is lower and higher than 900 ℃, the energy consumption is large, and the risk of local melting exists.
Further, in the above scheme, the cleaning agent used in the cleaning process in the step (1) is a hydrocarbon cleaning agent. Such as Exxsol D and Isopar hydrocarbon cleaners.
Compared with the existing preparation method, the invention has the following beneficial effects:
the invention takes the scraps produced in the production process as raw materials to prepare the electrode, reduces the use cost of the raw materials, simultaneously adopts the electroslag remelting process to remove impurities, and as the end of the consumable electrode is gradually melted, molten metal is gathered into liquid drops, passes through the slag bath, falls into the water-cooled crystallizer, is subjected to water cooling action, and is rapidly solidified.
The electroslag remelting is carried out under a vacuum condition, so that the prepared CuCr1-CuCr50 alloy has the characteristic of low gas content, an as-cast structure is obtained by an electroslag remelting process, and the prepared CuCr contact material has high density, so that the breaking performance of the contact is improved.
Drawings
FIG. 1 is a gold phase diagram of CuCr25 contact material prepared in example 2 of the present invention.
Fig. 2 is a gold phase diagram of the CuCr30 contact material prepared in example 6 of the present invention.
Fig. 3 is a gold phase diagram of the CuCr40 contact material prepared in example 7 of the present invention.
Detailed Description
The present invention is described in further detail below with reference to the drawings and the specific embodiments, which should not be construed as limiting the scope of the present invention, and the present invention may be modified and modified by the skilled engineer in the art.
Example 1
Preparation of CuCr10 contact material
The method comprises the following steps:
(1) cleaning and drying
Soaking and cleaning CuCr leftover bits by using cleaning equipment, wherein the used cleaning agent is an Exxsol D hydrocarbon cleaning agent, removing oil stains and impurities on the surface, and then drying to remove surface moisture;
(2) electrode pressing
Mixing two CuCr chips with 5% of Cr content and 30% of Cr content until the total Cr content is 10%, loading into a die for pressing, wherein the pressure is 100Mpa, and the pressure maintaining time is 2min, so that the density is more than 80%, and obtaining the electrode rod;
(3) charging furnace
Putting the prepared electrode bar into an electroslag furnace, connecting the electrode bar with a false electrode of a cathode, and ensuring that the electrode bar and the false electrode are coaxial and vertical; the crystallizer adopts a water-cooling copper mold, the gasket and the electrode are made of the same material, and the thickness is more than 3 mm; CaF is adopted as electroslag2Before use, the slag must be dried at 500 ℃, the baking time is 4 hours, and the temperature of the slag added into the crystallizer before arc striking is 130 ℃;
(4) electroslag remelting
After the charging is finished, the vacuum system is started, and when the vacuum is pumped to 3 × 10-1pa, switching on a power supply, filling argon into the furnace to-0.09 Mpa when the lower end of the electrode rod glows in red heat, and then further increasing the power, wherein the temperature is controlled at 1300 ℃. The molten metal drops at the end part of the electrode fall off under the action of gravity and pass through the slag pool to enter a metal molten pool, and the molten metal is rapidly solidified under the forced cooling action of the water-cooled crystallizer to form a fine chromium phase, namely a remelting CuCr block;
the remelting method comprises the following specific operations: when the power supply is switched on, the preliminary voltage is controlled at 20V, and the current is controlled at 1000.
(5) Thermal treatment
Annealing process is adopted to eliminate the ingot casting stress; the heat treatment temperature is controlled at 600 ℃, and the heat preservation time is 2 h.
(6) Machining
And (5) machining according to the drawing requirements.
Example 2
Preparation of CuCr25 contact material
The method comprises the following steps:
(1) cleaning and drying
Soaking and cleaning CuCr leftover bits by adopting cleaning equipment, removing oil stains and impurities on the surface by using an Isopar hydrocarbon cleaning agent, and then drying to remove surface moisture;
(2) electrode pressing
Directly selecting CuCr scraps with 25 percent of Cr content, putting the CuCr scraps into a die for pressing, wherein the pressure is 150Mpa, and the pressure maintaining time is 2min, so that the density is more than 80 percent, and obtaining the electrode rod;
(3) charging furnace
Putting the prepared electrode bar into an electroslag furnace, connecting the electrode bar with a false electrode of a cathode, and ensuring that the electrode bar and the false electrode are coaxial and vertical; the crystallizer adopts a water-cooling copper mold, the gasket and the electrode are made of the same material, and the thickness is more than 3 mm; the electroslag adopts Al2O3Before use, the slag must be dried at 500 ℃, the baking time is 4 hours, and the temperature of the slag added into the crystallizer before arc striking is 130 ℃;
(4) electroslag remelting
After the charging is finished, the vacuum system is started, and when the vacuum is pumped to 3 × 10-1pa, switching on a power supply, filling argon into the furnace to-0.09 Mpa when the lower end of the electrode rod glows in red heat, and then further increasing the power, wherein the temperature is controlled at 1300 ℃. The molten metal drops at the end part of the electrode fall off under the action of gravity and pass through the slag pool to enter a metal molten pool, and the molten metal is rapidly solidified under the forced cooling action of the water-cooled crystallizer to form a fine chromium phase, namely a remelting CuCr block;
the remelting method comprises the following specific operations: when the power supply is switched on, the preliminary voltage is controlled at 35V, and the current is controlled at 1600V.
(5) Thermal treatment
Annealing process is adopted to eliminate the ingot casting stress; the heat treatment temperature is controlled at 600 ℃, and the heat preservation time is 2 h.
(6) Machining
And (5) machining according to the drawing requirements.
Example 3
Preparation of CuCr40 contact material
The method comprises the following steps:
(1) cleaning and drying
Soaking and cleaning CuCr leftover bits by adopting cleaning equipment, removing oil stains and impurities on the surface by using an Isopar hydrocarbon cleaning agent, and then drying to remove surface moisture;
(2) electrode pressing
Mixing two CuCr chips with 5% of Cr content and 50% of Cr content until the total Cr content is 40%, loading into a die for pressing, wherein the pressure is 200Mpa, and the pressure maintaining time is 8min, so that the density is more than 80%, and obtaining the electrode rod;
(3) charging furnace
Putting the prepared electrode bar into an electroslag furnace, connecting the electrode bar with a false electrode of a cathode, and ensuring that the electrode bar and the false electrode are coaxial and vertical; the crystallizer adopts a water-cooling copper mold, the gasket and the electrode are made of the same material, and the thickness is more than 3 mm; the electroslag adopts MgO, slag must be dried under the condition of 600 ℃ before use, the baking time is 5 hours, and the temperature of the slag added into a crystallizer before arc striking is 350 ℃;
(4) electroslag remelting
After the charging is finished, the vacuum system is started, and when the vacuum is pumped to 3 × 10-1pa, switching on a power supply, filling argon into the furnace to-0.07 Mpa when the lower end of the electrode rod is hot and bright, and then further increasing the power and controlling the temperature at 1600 ℃. The molten metal drops at the end part of the electrode fall off under the action of gravity and pass through the slag pool to enter a metal molten pool, and the molten metal is rapidly solidified under the forced cooling action of the water-cooled crystallizer to form a fine chromium phase, namely a remelting CuCr block;
the remelting method comprises the following specific operations: when the power supply is switched on, the preliminary voltage is controlled at 58V, and the current is controlled at 3000A.
(5) Thermal treatment
Annealing process is adopted to eliminate the ingot casting stress; the heat treatment temperature is controlled at 700 ℃, and the heat preservation time is 3 h.
(6) Machining
And (5) machining according to the drawing requirements.
Example 4
Preparation of CuCr50 contact material
The method comprises the following steps:
(1) cleaning and drying
Soaking and cleaning CuCr leftover bits by using cleaning equipment, wherein the used cleaning agent is an Exxsol D hydrocarbon cleaning agent, removing oil stains and impurities on the surface, and then drying to remove surface moisture;
(2) electrode pressing
CuCr scraps with the Cr content of 50% are filled into a die to be pressed, the pressure is 300Mpa, the pressure maintaining time is 15min, the density is more than 80%, and an electrode bar is obtained;
(3) charging furnace
Putting the prepared electrode bar into an electroslag furnace, connecting the electrode bar with a false electrode of a cathode, and ensuring that the electrode bar and the false electrode are coaxial and vertical; the crystallizer adopts a water-cooling copper mold, the gasket and the electrode are made of the same material, and the thickness is more than 3 mm; the electroslag adopts CaO, slag must be dried under the condition of 800 ℃ before use, the baking time is 7 hours, and the temperature of the slag added into a crystallizer before arc striking is 500 ℃;
(4) electroslag remelting
After the charging is finished, the vacuum system is started, and when the vacuum is pumped to 3 × 10-1pa, switching on a power supply, filling argon into the furnace to 0.6Mpa when the lower end of the electrode rod is hot and bright, and then further increasing the power, wherein the temperature is controlled at 2000 ℃. The molten metal drops at the end part of the electrode fall off under the action of gravity and pass through the slag pool to enter a metal molten pool, and the molten metal is rapidly solidified under the forced cooling action of the water-cooled crystallizer to form a fine chromium phase, namely a remelting CuCr block;
the remelting method comprises the following specific operations: when the power supply is switched on, the initial voltage is controlled at 85V, and the current is controlled at 5000A.
(5) Thermal treatment
Annealing process is adopted to eliminate the ingot casting stress; the heat treatment temperature is controlled at 900 ℃, and the heat preservation time is 4 h.
(6) Machining
And (5) machining according to the drawing requirements.
Example 5
The difference from the example 2 is that the remelting is performed for 4 times in the step (4), wherein the remelting for the last 3 times is specifically: putting the first-remelting CuCr block serving as a secondary electrode into a vacuum consumable arc furnace for secondary smelting to obtain a secondary remelting CuCr block, and remelting the secondary remelting CuCr block according to the first remelting operation to obtain a third remelting CuCr block; and then the third-time remelting CuCr block is placed into a vacuum consumable arc furnace to be treated according to the second smelting operation, and the electrode bar after 4 times remelting treatment is obtained.
The specific process parameters of the 2 nd smelting and the 4 th smelting are as follows: the crystallizer adopts a water-cooling copper mold, the specification of the crystallizer is phi 500mm, the vacuum degree before melting is less than or equal to 3Pa, the gas leakage rate is less than or equal to 1.5Pa/min, the melting voltage is 45V, the melting current is 10KA, the arc stabilizing current adopts direct current 15A, and the cooling time after melting is 0.5 h.
Example 6
In contrast to example 3, it is pointed out that in step (4) a total of 4 remelting operations are carried out, wherein the last 3 remelting operations are specifically: putting the first-remelting CuCr block serving as a secondary electrode into a vacuum consumable arc furnace for secondary smelting to obtain a secondary remelting CuCr block, and remelting the secondary remelting CuCr block according to the first remelting operation to obtain a third remelting CuCr block; and then the third-time remelting CuCr block is placed into a vacuum consumable arc furnace to be treated according to the second smelting operation, and the electrode bar after 4 times remelting treatment is obtained.
The specific process parameters of the 2 nd smelting and the 4 th smelting are as follows: the crystallizer adopts a water-cooled copper mold, the specification of the crystallizer is phi 550mm, the vacuum degree before melting is less than or equal to 3Pa, the gas leakage rate is less than or equal to 1.5Pa/min, the melting voltage is 50V, the melting current is 12KA, the arc stabilizing current adopts direct current 18A, and the cooling time after melting is 1 h.
Example 7
The difference from the example 4 is that the remelting is carried out for 4 times in the step (4), wherein the remelting for the last 3 times is specifically: putting the first-remelting CuCr block serving as a secondary electrode into a vacuum consumable arc furnace for secondary smelting to obtain a secondary remelting CuCr block, and remelting the secondary remelting CuCr block according to the first remelting operation to obtain a third remelting CuCr block; and then the third-time remelting CuCr block is placed into a vacuum consumable arc furnace to be treated according to the second smelting operation, and the electrode bar after 4 times remelting treatment is obtained.
The specific process parameters of the 2 nd smelting and the 4 th smelting are as follows: the crystallizer adopts a water-cooled copper mold, the specification of the crystallizer is phi 600mm, the vacuum degree before melting is less than or equal to 3Pa, the gas leakage rate is less than or equal to 1.5Pa/min, the melting voltage is 60V, the melting current is 15KA, the arc stabilizing current adopts direct current 20A, and the cooling time after melting is 2 h.
The product performance parameters prepared in examples 1-7 above are shown in Table 1:
table 1: property parameters of the products prepared in examples 1 to 7
The data show that the CuCr contact material prepared by the invention has lower oxygen and nitrogen contents, high density, high hardness and good conductivity.
Moreover, as can be seen from comparison of the data of the embodiment 2 and the embodiment 2, and the data of the embodiment 3 and the embodiment 6, and the data of the embodiment 4 and the embodiment 7, after the electrode bar is subjected to the remelting treatment 4 times, the content of oxygen and nitrogen is further reduced, the compactness is further improved, the hardness is further increased, the electrical conductivity is better, and the breaking performance of the contact is improved.
Claims (9)
1. A preparation method of a low-cost fine-grain CuCr contact material is characterized by comprising the following steps:
(1) cleaning and drying
Soaking and cleaning CuCr leftover bits by adopting cleaning equipment to remove oil stains and impurities on the surface, and then drying to remove water on the surface;
(1) electrode pressing
Mixing CuCr chips with different Cr contents to 1-50% according to the requirement, putting the mixture into a die for pressing, wherein the pressure is 100-300Mpa, and the pressure maintaining time is 2-15min, so that the density is more than 80%, and obtaining the electrode rod;
(2) charging furnace
Putting the prepared electrode bar into an electroslag furnace, connecting the electrode bar with a false electrode of a cathode, and ensuring that the electrode bar and the false electrode are coaxial and vertical; the crystallizer adopts a water-cooling copper mold, the gasket and the electrode are made of the same material, and the thickness is more than 3 mm; the temperature of slag added into the crystallizer before starting arc is not lower than 130 ℃;
(3) electroslag remelting
After the charging is finished, the vacuum system is started, and when the vacuum is pumped to 3 × 10-1pa, power on, start vacuum system, when vacuum is 3 × 10-1pa, remelting, wherein metal droplets at the end part of the electrode fall off under the action of gravity, pass through the slag pool and enter the metal molten pool, and molten metal is rapidly solidified under the forced cooling action of the water-cooled crystallizer to form a fine chromium phase, namely a remelting CuCr block;
(4) thermal treatment
Annealing process is adopted to eliminate the ingot casting stress;
(5) machining
And (5) machining according to the drawing requirements.
2. The method of claim 1 wherein the step (2) of pressing the electrode is performed by mixing two CuCr chips with a Cr content of 5% and a Cr content of 30% to a total Cr content of 25%.
3. The method of claim 1, wherein the electroslag in the electroslag furnace in step (3) is CaF2、Al2O3MgO or CaO, the slag must be dried at the temperature of 500-800 ℃ before use, and the baking time is not less than 4 hours.
4. The method for preparing a low-cost fine-grained CuCr contact material according to claim 1, wherein the remelting in step (4) comprises the following specific operations: when the power supply is switched on, the initial voltage is controlled to be 20-85V, the current is controlled to be 1000-5000A, when the lower end of the electrode rod glows in red heat, argon is filled into the furnace to be-0.09 to-0.6 Mpa, then the power is further improved, and the temperature is controlled to be 1300-2000 ℃. .
5. The method of claim 4 wherein the remelting step (4) is repeated 4 times in total.
6. The method for preparing a low-cost fine-grained CuCr contact material according to claim 5, wherein the last 3 remelting times out of the 4 remelting times are specifically: putting the first-remelting CuCr block serving as a secondary electrode into a vacuum consumable arc furnace for secondary smelting to obtain a secondary remelting CuCr block, and remelting the secondary remelting CuCr block according to the first remelting operation to obtain a third remelting CuCr block; and then the third-time remelting CuCr block is placed into a vacuum consumable arc furnace to be treated according to the second smelting operation, and the electrode bar after 4 times remelting treatment is obtained.
7. The method for preparing the low-cost fine-grained CuCr contact material according to claim 6, wherein the specific process parameters of the 2 nd smelting and the 4 th smelting are as follows: the crystallizer adopts a water-cooled copper mold, the specification of the crystallizer is phi 500-phi 600mm, the vacuum degree before melting is less than or equal to 3Pa, the gas leakage rate is less than or equal to 1.5Pa/min, the melting voltage is 45-60V, the melting current is 10-15 KA, the arc stabilizing current adopts direct current of 15-20A, and the cooling time after melting is 0.5-2 h.
8. The method for preparing a low-cost fine-grained CuCr contact material as claimed in claim 1, wherein the heat treatment temperature in step (5) is controlled to be between 600 ℃ and 900 ℃, and the heat preservation time is 2-4 h.
9. The method for preparing a low-cost fine-grained CuCr contact material according to claim 1, wherein the cleaning agent used in the cleaning process in step (1) is a hydrocarbon cleaning agent.
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| CN116083739A (en) * | 2022-12-08 | 2023-05-09 | 陕西斯瑞新材料股份有限公司 | Preparation method of high-purity low-pressure environment-friendly copper-chromium contact |
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