CN1021302C - Technology for casting double-layer metallic material (steel body with copper liner) - Google Patents

Abstract

The present invention relates to a technology for casting a double-layer metallic material of a steel body with a copper liner, which belongs to a bimetallic processing technology. The mobile atmosphere in heating a base body and pouring is kept; an inert atmosphere or a reducing atmosphere is orderly changed into a reducing atmosphere or an inert atmosphere, and the surface to be adhered of the base body strictly conforms to the requirement of pouring; a moderate decarbonizing capability in the atmosphere is properly increased for a medium carbon or high carbon iron-carbon alloy basal body. The technology not only can obtain double-layer antifriction metallic material with reliable adhesion and stable quality, but also enlarge the range of material for the base body and increase new variety. The present invention has the advantages of reasonable technological design, easy satisfaction of technological condition, low cost and broad prospect of industrial implementation.

Description

Technology for casting double-layer metallic material (steel body with copper liner)

The invention belongs to the bimetallic processing technology, relate generally to the cast of becoming a useful person of matrix and anti-attrition layer material.

Known quiet cast is the method for becoming a useful person of steel body brass material, applicable to manufacturing of conventional steel body brass double-layer metal material, and technology is comparatively simple, be widely adopted, but in actual applications, the bond strength of double-level-metal, casting quality is all than difficult control, basic material there is certain requirement again, thereby brings influence to use.

The present invention seeks to propose to improve double-level-metal bond strength, the pouring technology of stabilized product quality.

The present invention seeks to realize like this, comprise the cleaning of giving successively to bimetallic matrix bond face place, the matrix heating, cast is treated in conjunction with lining material molten metal, the cooling of bonding back is until becoming a useful person, wherein, should keep suitable mobile atmosphere in the cast stage being heated to, promptly keep inert atmosphere or reducing atmosphere in the heating starting stage, its atmosphere and strength exceeds with the matrix oxidation that keeps from heat, should guarantee to be reducing atmosphere in the heating later stage, reduction intensity exceeds with the oxide on abundant reduction matrix bond surface, change inert atmosphere into before the cast to be performed, in inert atmosphere, pour into a mould.Like this, mobile atmosphere helps getting rid of matrix bond face place, in heating process, produce and be unfavorable for pouring into a mould the product of combination, keep normal atmosphere, it is oxidized that the atmosphere control of starting stage can prevent that the matrix bond face is in the heating process, reducing atmosphere subsequently then can fully reduce the existing oxidized surface in matrix bond face place, eliminates and hinders the oxide of bimetallic combination, and matrix bond place surface-active is strengthened.Thereby the bond strength between the increase double-level-metal makes constant product quality, and the object of the invention is achieved.

When the present invention is medium high carbon iron-carbon alloy material when matrix, in mobile atmosphere of heating later stage starting stage, add oxygen or the moisture content that certain content is arranged, the intensity of its content and atmosphere should be controlled at and make matrix treat that mating surface produces appropriate decarburization, its decarbonization degree requires to exceed with the normal carbon containing that combines of matrix to satisfy desire cast lining material metal, after this then be connected mutually, become a useful person until cast with the operation that reducing atmosphere is kept in heating the later stage.The formation of change initial stage heating atmosphere, adapted to and changed the back basic material, the combination of having satisfied double-layer metal material simultaneously requires, thereby enlarged suitable application area of the present invention, the concrete parameter of nature later stage reducing atmosphere will be distinguished with low carbon base body to some extent according to heating the oxide content decision that the rear surface exists early stage.

The present invention initially is controlled at 600-900 ℃ with the temperature spot that is connected of later stage heating.Therefore can select less expensive and the lower inert atmosphere of quality index for use before, to avoid the oxidation tendency in the heating process, after being connected temperature, then remove matrix and treat that the reduction condition of faying face oxide is content with very little, thereby make bond matrix or fusion face cleaning, non-oxidation is mingled with, can be in strict conformity with the cast requirement, and higher linking temperature also can satisfy the decarburization requirement of the medium high carbon matrix being treated the faying face place.

The present invention is by the ambiance at faying face place in the static cast heating process of control double-level-metal, hold the state of the preceding faying face of cast effectively, thereby fully satisfy the particular requirement of double-level-metal cast to the matrix bond face, improved the quality of becoming a useful person, propose to reduce the concrete approach of matrix surface phosphorus content, enlarged the selection range of matrix, increased the kind of double-layer metal material, improve its performance, enlarged the applicable situation of double-level-metal alloy; The condition of this process implementing satisfies easily, and technological parameter is easy to control, stable technical process, and the also economical rationality of required cost has the industrial implementation prospect.

Accompanying drawing provides process chart, with simple and clear statement main contents of the present invention.

Fig. 1 is technology for casting double-layer metallic material (steel body with copper liner) figure;

Fig. 2 is medium high carbon iron-carbon alloy matrix double-layer metal material pouring technology figure.

First embodiment is the pouring technology of double-level-metal axle sleeve, and its matrix is a mild steel, and phosphorus content is less than 0.25%, and the brass alloy of cast is a lead bronze, and its composition is formed: Pb-19%, Sn-1.5%, Ni＜0.5%.

At first the steel body is tentatively cleared up, removed greasy dirt, steel cuttings or the steel end that the steel body adheres in alkali lye when machined, the washing flood is done then.Subsequently the steel body is put into heating furnace and heat, and the steel body is waited that the adhesive surface or the die cavity that inject copper alloy pass to gas, this gas should be nitrogen or other inert gas or other reducibility gas.Generally select for use nitrogen comparatively economical, can prevent that like this matrix is heated and produces oxidation, and residual volatile matters such as greasy dirt are taken away with gas.The gas flow that feeds should guarantee the interior malleation of institute's cavity that feeds.During heating, should make the temperature at each position of steel body even as far as possible, programming rate is fast as far as possible.When temperature reaches 800 ℃, change logical hydrogen or cracked ammonium hydrogen-nitrogen mixture gas.The oxide that main reduction adhesive surface has, the reducing gas dew point that is fed is not more than-30 ℃.After this continue to be warming up to 1100 ℃ of pouring temperatures, the reduction processing time before the pouring temperature is not less than 30 minutes.Change logical nitrogen protection before the cast, because of hydrogen and copper alloy have inspiratory phenomenon.After need treating the hydrogen emptying, melted copper alloy can be poured in the steel body.Sometimes according to material and adhesion strength requirement, also can after pouring copper alloy, be incubated 5-20 minute or the temperature that further raises to more than the copper alloy fusing point about 150 ℃, be incubated 5-20 minute, strengthen diffusion bonding.After copper alloy poured, the steel body just can take out from stove, cools off.Cooling can be carried out in air, or carries out water flowing by certain mode and cool off indirectly, and direct water-cooling should not adopt in order to avoid produce stress guide to copper alloy and crackle occur.

The copper alloy that adopts above-mentioned technology and this example to provide, casting is after test to foundry goods, and the adhesion strength of matrix and brass can reach 140N/mm ², bonding is firm, and steel body and brass adhesive surface do not have any oxide inclusions.

Second embodiment is high-pressure plunger pump double-level-metal cylinder body, its matrix is a medium carbon steel, manufacture process is as follows: when carrying out the double-level-metal cast on the steel body high to phosphorus content, need tentatively clear up the steel body equally, in alkali lye, clean remover processing back attached steel cuttings or steel end, washing oven dry then, subsequently the steel body being put into heating furnace heats, and pass to nitrogen or other inert gas or reducibility gas, and can be identical with example 1, still select comparatively economic nitrogen for use.Because the existence of carbon plays a part to hinder bonding, so the higher steel body of phosphorus content is carried out the carbonization treatment of bonding surface.When steel body heating-up temperature raises in this example, owing to select for use the gas of feeding to be without special purification processes, to contain a certain amount of oxygen and moisture content, steel body bonding surface is planted the effect that feeds gas therewith, the emaciated face of can making a list carbon, the power of this phenomenon can be by control temperature, duration, and the oxygen content or the moisture content amount that feed gas are controlled, general heating-up temperature height, longer duration, oxygen content gas or then decarburization phenomenon of water content height are strong; Otherwise then, it is selected can be by checking that the bond effect of casting the back test specimen is tested.This example when temperature reaches 850 °-900 ℃, is-10 ℃ to the gas dew point that feeds, decarburization temperature retention time 20-40 minute after finishing said process, promptly changes logical reducibility gas hydrogen, fully go back the oxide of raw steel body adhesive surface, this gas dew point is not more than-30 ℃.Reduction this moment and intensification can be carried out simultaneously, but must guarantee that the reduction processing time before the extremely cast is no less than 30 minutes.This routine pouring temperature is 1050 ℃, changes logical nitrogen protection before cast, treat the hydrogen emptying after, melted copper alloy solution is poured in the steel body, insulation fully fusion in 5 minutes in stove then can be taken out the steel body after the casting and be placed on the steel plate, water flowing is cooled off indirectly.

When the copper alloy composition is Pb-15%, Sn-8%, Zn-3%, Ni-1.5%, when Cu was surplus, the adhesion strength of casting back brass material and steel body reached 216N/mm ², be bonded to power and reach absolutely.

The 3rd embodiment,, should be higher than steel matrix far away so feed the decarburization of gas, but can not make a large amount of oxidations of top layer iron because the phosphorus content height also has the free carbon that exists with the graphite form in the first stage of heating for forming the double-layer metal material of cast iron matrix.Gas composition to feeding is the air that 90-96% nitrogen or inert gas add 3-8%, or 95-98% nitrogen or inert gas add the water vapour of 2-4%, the decarburization temperature of its initial heating should suitably be increased to 900-1000 ℃, decarburization temperature retention time 20-40 minute, after finishing said process, still reduce processing, guarantee the abundant reduction of oxide, when reaching cast temperature 950-1100 ℃ with hydrogen or cracked ammonium hydrogen-nitrogen mixture gas.Other technical process is the same.To the decarburization gas that feeds, also can directly select conversion coal gas for use, furnace gas takes place, water-gas etc.After stating technology on the implementation, the making of cast iron matrix bimetallic material is achieved, has further enlarged the selection range of matrix material.

Claims (3)

1, technology for casting double-layer metallic material (steel body with copper liner), be to comprise carrying out successively double-level-metal matrix bond face place is given cleaning, the matrix heating, cast is then desired in conjunction with molten metal, be cooled to the basic technology of becoming a useful person after the bonding, it is characterized in that the faying face place should keep suitable mobile atmosphere in the stage of cast being heated to, the heating starting stage should be inert atmosphere or reducing atmosphere, and atmosphere and strength exceeds with the further oxidation of the matrix that keeps from heat; Later stage should guarantee to be reducing atmosphere in heating, reduction intensity exceeds with the oxide at reduction faying face place, changes inert atmosphere into before to be cast, casts in inert atmosphere.

2, pouring technology described in claim 1, it is characterized in that when matrix is the iron-carbon alloy of senior middle school's carbon, the atmosphere in its initial heat-up stage later stage contains a certain amount of oxygen or moisture, its content and atmosphere and strength are except that satisfying matrix pouring intensification, also need make matrix bond surface produce appropriate decarburization, this decarbonization degree is so that matrix bond face place phosphorus content satisfies the requirement of brass material cast bonding exceeds; After this still need to be connected mutually, until end of a period with the operation of the reducing atmosphere of keeping the heating later stage.

3, technology as claimed in claim 1 or 2 is characterized in that the linking temperature that heats initial and later stage is controlled at 600-900 ℃.

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