CN105483324A - Casting state high-strength high-elongation steel casting material for car axle housing - Google Patents

Abstract

The invention discloses a casting state high-strength high-elongation steel casting material for a car axle housing. The casting state high-strength high-elongation steel casting material comprises, by weight, 95-98 parts of steel scrap (with the iron content being not smaller than 98%), 2-3 parts of Z18 pig iron, 0.8-0.9 part of silicon carbide, 0.02-0.03 part of niobium, 0.8-1 part of manganese, 0.05-0.06 part of aluminum nitride, 0.02-0.022 part of zirconium, 0.17-0.2 part of chromium, 0.8-0.86 part of calcium silicide, 0.5-0.6 part of slightly calcined dolomite, 0.3-0.32 part of calcined petroleum coke, 0.23-0.25 part of pure acrylic emulsion and not larger than 0.01 part of impurities. The casting state high-strength high-elongation steel casting material is reasonable in proportion; and after improved simple process treatment, a casting state material has the higher extension strength and high elongation, and is resistant to impact toughness, capable of meeting the mechanical performance requirements of transmission parts and impacted parts on a large-tonnage and large-traction-force heavy-duty car, and quiet suitable for manufacturing the heavy-duty car axle housing.

Description

A kind of automobile axle housing cast steel material of as cast condition high strength high extensibility

Technical field

The present invention relates to cast material technical field, particularly relate to a kind of automobile axle housing cast steel material of as cast condition high strength high extensibility.

Background technology

Automotive axle is one of vehicle key component, and it is the integral part of power train, is also the important component part of running gear.Automobile axle housing, as the main part of vehicle bridge, is ensure that automobile normally runs the key part with work-ing life, so all have higher requirements to its physical strength, rigidity and fatigue performance etc.Axle housing production cost accounts for 30 percent of driving axis basis.Particularly heavy-duty car is operationally because road and operating mode are severe, and axle housing subjects strong shock load, higher to the quality requirements of axle housing.Plate weldering axle housing, due to the restriction by self structure and weldprocedure, in use easily deforms, occurs the phenomenon such as leakage of oil and crackle, be difficult to the need of work meeting heavy-duty car.For this reason, in order to meet the needs that automobile bearing capacity increases, the especially demand of heavy-duty car, needs to research and develop a kind of cast steel material, meets the needs of automotive axle, can obtain certain economic and social benefit simultaneously.The intensity hardness of as cast condition cast steel is very low, impact is poor, cannot meet the service requirements of material, must carry out suitable thermal treatment, to guarantee the safety applications of high-strength toughness low alloy cast steel, utilizes thermal treatment process to excavate cast steel potential simultaneously, expands its range of application.

Summary of the invention

The object of the invention is exactly the defect in order to make up prior art, provides a kind of automobile axle housing cast steel material of as cast condition high strength high extensibility.

The present invention is achieved by the following technical solutions:

An automobile axle housing cast steel material for as cast condition high strength high extensibility, is made up of the raw material of following weight part: steel scrap (iron level is not less than 98%) 95-98, Z18 pig iron 2-3, silicon carbide 0.8-0.9, niobium 0.02-0.03, manganese 0.8-1, aluminium nitride 0.05-0.06, zirconium 0.02-0.022, chromium 0.17-0.2, calcium silicide 0.8-0.86, light dolomite 0.5-0.6, after-smithing petroleum coke 0.3-0.32, pure-acrylic emulsion 0.23-0.25, impurity≤0.01.

The automobile axle housing cast steel material of described a kind of as cast condition high strength high extensibility, is prepared from by following concrete steps:

(1) all instruments and mould are carried out heat treated under 250 DEG C of conditions, for subsequent use after taking out; Steel scrap, the Z18 pig iron, silicon carbide being carried out being broken into small-particle respectively, then puts into ball mill, passing under argon gas state ball milling 4 hours, obtaining composite powder; In vacuum induction furnace, drop into composite powder, heat up and be heated to complete melting, then hot rolling, makes steel billet after cooling;

(2) light dolomite is mixed with after-smithing petroleum coke, put into crusher and be ground into small-particle, then jointly send in ball mill with calcium silicide, add suitable quantity of water wet-milling 40 minutes, take out post-drying, obtain mixed powder; By pure-acrylic emulsion dilute with water 3 times, dispersed with stirring evenly rear and mixed powder sends into extruding pelletization in tablets press jointly; The particle obtained is sent into baking oven and toasts 40 minutes with the temperature of 100 DEG C, then send into 10 DEG C/min of ramp to 460 DEG C in sintering oven, sinter 1.5 hours, taking-up is cooled to room temperature, obtains mixing reductor;

(3) steel billet that step (1) obtains is put into medium-frequency induction furnace and be heated to molten state, be incubated and remove slag after 1 hour, until furnace charge molten clear after, add all the other remaining components and carry out melting, tap after temperature being raised to 1630-1660 DEG C, add the composite deoxidant that step (2) obtains and carry out final deoxidation, then remove the gred, after temperature reaches 1550 DEG C, mixing molten steel is poured in the sand mold of well in advance;

(4) foundry goods is through unpacking, heat-treating after sand removal, foundry goods is sent into be full of in the chamber type electric resistance furnace of nitrogen and is heated to 880 DEG C, be incubated 60 minutes, then foundry goods is taken out air cooling, to be cooledly to room temperature, continue to be fed into tempering in chamber type electric resistance furnace, be heated to 580 DEG C of insulations 90 minutes, taking-up air cooling is to room temperature and get final product.

Advantage of the present invention is: the present invention, by scientific and reasonable composition proportion, adopts steel scrap as main iron, by the method for mechanical alloying in advance, achieves the compound of iron, carbon, element silicon; The composite deoxidant with vesicular structure is made by suitable technique by adding the compositions such as calcium silicide in the preparation technology of cast steel, can fast and molten steel react, there is the effect of good deoxidation, desulfurization, carburetting, fluidity molten steel can be improved simultaneously, effective removal inclusion content in melting steel, improves Molten Steel Cleanliness; Again by reasonable thermal treatment process easily, obtain the cast steel material that a kind of intensity is high, plasticity good, low-temperature flexibility is good over-all properties is high.

Reasonable ratio of the present invention, after modified easy art breading, as cast condition material is made to have higher tensile strength, high elongation and toughness, the mechanical property requirements of large-tonnage, high tractive force heavy-duty car upper driving component and the component that are hit can be met, be applicable to very much manufacturing heavy-duty car axle housing, and cast steel material preparation technology of the present invention is simple, technique is convenient to industrialized production, is worthy to be popularized.

Embodiment

An automobile axle housing cast steel material for as cast condition high strength high extensibility, is made up of the raw material of following weight part (kilogram): steel scrap (iron level is not less than 98%) 95, the Z18 pig iron 2, silicon carbide 0.8, niobium 0.02, manganese 0.8, aluminium nitride 0.05, zirconium 0.02, chromium 0.17, calcium silicide 0.8, light dolomite 0.5, after-smithing petroleum coke 0.3, pure-acrylic emulsion 0.23, impurity≤0.01.

The automobile axle housing cast steel material of described a kind of as cast condition high strength high extensibility, is prepared from by following concrete steps:

(1) all instruments and mould are carried out heat treated under 250 DEG C of conditions, for subsequent use after taking out; Steel scrap, the Z18 pig iron, silicon carbide being carried out being broken into small-particle respectively, then puts into ball mill, passing under argon gas state ball milling 4 hours, obtaining composite powder; In vacuum induction furnace, drop into composite powder, heat up and be heated to complete melting, then hot rolling, makes steel billet after cooling;

(2) light dolomite is mixed with after-smithing petroleum coke, put into crusher and be ground into small-particle, then jointly send in ball mill with calcium silicide, add suitable quantity of water wet-milling 40 minutes, take out post-drying, obtain mixed powder; By pure-acrylic emulsion dilute with water 3 times, dispersed with stirring evenly rear and mixed powder sends into extruding pelletization in tablets press jointly; The particle obtained is sent into baking oven and toasts 40 minutes with the temperature of 100 DEG C, then send into 10 DEG C/min of ramp to 460 DEG C in sintering oven, sinter 1.5 hours, taking-up is cooled to room temperature, obtains mixing reductor;

(3) steel billet that step (1) obtains is put into medium-frequency induction furnace and be heated to molten state, be incubated and remove slag after 1 hour, until furnace charge molten clear after, add all the other remaining components and carry out melting, tap after temperature being raised to 1630 DEG C, add the composite deoxidant that step (2) obtains and carry out final deoxidation, then remove the gred, after temperature reaches 1550 DEG C, mixing molten steel is poured in the sand mold of well in advance;

(4) foundry goods is through unpacking, heat-treating after sand removal, foundry goods is sent into be full of in the chamber type electric resistance furnace of nitrogen and is heated to 880 DEG C, be incubated 60 minutes, then foundry goods is taken out air cooling, to be cooledly to room temperature, continue to be fed into tempering in chamber type electric resistance furnace, be heated to 580 DEG C of insulations 90 minutes, taking-up air cooling is to room temperature and get final product.

Product of the present invention carries out bench testing according to QC/T533-1999 " automobile drive axle Bench test methods " and QC/T534-1999 " automobile drive axle bench testing evaluation index ", its vertical curve fatigue life test cycle index is more than or equal to 800,000 times, vertical curve test of static strength ultimate load is more than or equal to 800KN, all meets automobile industry standard.

Claims (2)

1. the automobile axle housing cast steel material of an as cast condition high strength high extensibility, it is characterized in that, be made up of the raw material of following weight part: steel scrap (iron level is not less than 98%) 95-98, Z18 pig iron 2-3, silicon carbide 0.8-0.9, niobium 0.02-0.03, manganese 0.8-1, aluminium nitride 0.05-0.06, zirconium 0.02-0.022, chromium 0.17-0.2, calcium silicide 0.8-0.86, light dolomite 0.5-0.6, after-smithing petroleum coke 0.3-0.32, pure-acrylic emulsion 0.23-0.25, impurity≤0.01.

2. the automobile axle housing cast steel material of a kind of as cast condition high strength high extensibility according to claim 1, is characterized in that, be prepared from by following concrete steps:

(1) all instruments and mould are carried out heat treated under 250 DEG C of conditions, for subsequent use after taking out; Steel scrap, the Z18 pig iron, silicon carbide being carried out being broken into small-particle respectively, then puts into ball mill, passing under argon gas state ball milling 4 hours, obtaining composite powder; In vacuum induction furnace, drop into composite powder, heat up and be heated to complete melting, then hot rolling, makes steel billet after cooling;

(2) light dolomite is mixed with after-smithing petroleum coke, put into crusher and be ground into small-particle, then jointly send in ball mill with calcium silicide, add suitable quantity of water wet-milling 40 minutes, take out post-drying, obtain mixed powder; By pure-acrylic emulsion dilute with water 3 times, dispersed with stirring evenly rear and mixed powder sends into extruding pelletization in tablets press jointly; The particle obtained is sent into baking oven and toasts 40 minutes with the temperature of 100 DEG C, then send into 10 DEG C/min of ramp to 460 DEG C in sintering oven, sinter 1.5 hours, taking-up is cooled to room temperature, obtains mixing reductor;

(3) steel billet that step (1) obtains is put into medium-frequency induction furnace and be heated to molten state, be incubated and remove slag after 1 hour, until furnace charge molten clear after, add all the other remaining components and carry out melting, tap after temperature being raised to 1630-1660 DEG C, add the composite deoxidant that step (2) obtains and carry out final deoxidation, then remove the gred, after temperature reaches 1550 DEG C, mixing molten steel is poured in the sand mold of well in advance;

(4) foundry goods is through unpacking, heat-treating after sand removal, foundry goods is sent into be full of in the chamber type electric resistance furnace of nitrogen and is heated to 880 DEG C, be incubated 60 minutes, then foundry goods is taken out air cooling, to be cooledly to room temperature, continue to be fed into tempering in chamber type electric resistance furnace, be heated to 580 DEG C of insulations 90 minutes, taking-up air cooling is to room temperature and get final product.