CN105568119A - High-temperature-resistant excellent-performance cast steel material for automobile part - Google Patents

Abstract

The invention discloses a high-temperature-resistant excellent-performance cast steel material for an automobile part. The high-temperature-resistant excellent-performance cast steel material for the automobile part is prepared from, by weight, 95-98 parts of waste steel (the iron content of the waste steel is not smaller than 98%), 2-3 parts of Z18 pig iron, 0.4-0.45 part of crystal silicon, 0.6-0.7 part of nickel-aluminum intermediate compounds, 0.1-0.12 part of nitrogen, 1.8-2 parts of manganese, 0.7-0.8 part of chromium, 0.3-0.33 part of carbon, 0.8-0.86 part of calcium silicon, 0.4-0.45 part of quartz, 0.7-0.73 part of white clay, 0.3-0.4 part of silica solutions, 0.2-0.23 part of pregelatinized starch and 0-0.01 part of impurities. According to the high-temperature-resistant excellent-performance cast steel material for the automobile part, the component proportion is scientific and reasonable; the cast steel material which is excellent in high temperature resistance and erosive wear resistance can be prepared by adding a proper quantity of nickel-aluminum intermediate compounds in the smelting process; the automobile part, especially an exhaust pipe or a turbine housing, made of the material has higher temperature bearing capacity and durability.

Description

A kind of automobile component cast steel material of resistance to elevated temperatures excellence

Technical field

The present invention relates to cast material technical field, particularly relate to a kind of automobile component cast steel material of resistance to elevated temperatures excellence.

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 component cast steel material of resistance to elevated temperatures excellence.

The present invention is achieved by the following technical solutions:

An automobile component cast steel material for resistance to elevated temperatures excellence, 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 metal 0.4-0.45, nickel aluminium intermediate compound 0.6-0.7, nitrogen 0.1-0.12, manganese 1.8-2, chromium 0.7-0.8, carbon 0.3-0.33, calcium silicide 0.8-0.86, quartzy 0.4-0.45, white clay 0.7-0.73, silicon sol 0.3-0.4, pregelatinized Starch 0.2-0.23, impurity≤0.01.

The automobile component cast steel material of described a kind of resistance to elevated temperatures excellence, 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, carbon, silicon metal 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) mix with white clay, calcium silicide after quartz being broken into small-particle, put into ball mill ball milling 90 minutes, after taking-up, add the water of total amount 2 times amount, silicon sol, sonic oscillation leaves standstill after 40 minutes and filters, filter cake is dried under the condition of 100 DEG C, crosses 400 mesh sieves, obtain mixed powder; Pregelatinized Starch is added in the water of 3 times amount, after being heated to while stirring to dissolve completely and mixed powder jointly send in tablets press, stir extruding pelletization after 15 minutes, particle is sent into baking oven to send in sintering oven with 8 DEG C/min of ramp to 480 DEG C after dry 30 minutes with the temperature of 120 DEG C, sinter 90 minutes, 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.

Present component proportioning is scientific and reasonable, by adding appropriate nickel aluminium intermediate compound in fusion process, the cast steel material that high temperature resistant Erosive Properties is good can be made, material of the present invention is utilized to make automobile component, especially vapor pipe, turbine case etc., has and higher holds warm ability and endurance quality.

Embodiment

An automobile component cast steel material for resistance to elevated temperatures excellence, 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 metal 0.4, nickel aluminium intermediate compound 0.6, nitrogen 0.1, manganese 1.8, chromium 0.7, carbon 0.3, calcium silicide 0.8, quartz 0.4, white clay 0.7, silicon sol 0.3, pregelatinized Starch 0.2, impurity≤0.01.

The automobile component cast steel material of described a kind of resistance to elevated temperatures excellence, 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, carbon, silicon metal 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) mix with white clay, calcium silicide after quartz being broken into small-particle, put into ball mill ball milling 90 minutes, after taking-up, add the water of total amount 2 times amount, silicon sol, sonic oscillation leaves standstill after 40 minutes and filters, filter cake is dried under the condition of 100 DEG C, crosses 400 mesh sieves, obtain mixed powder; Pregelatinized Starch is added in the water of 3 times amount, after being heated to while stirring to dissolve completely and mixed powder jointly send in tablets press, stir extruding pelletization after 15 minutes, particle is sent into baking oven to send in sintering oven with 8 DEG C/min of ramp to 480 DEG C after dry 30 minutes with the temperature of 120 DEG C, sinter 90 minutes, 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 component cast steel material of a resistance to elevated temperatures excellence, 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 metal 0.4-0.45, nickel aluminium intermediate compound 0.6-0.7, nitrogen 0.1-0.12, manganese 1.8-2, chromium 0.7-0.8, carbon 0.3-0.33, calcium silicide 0.8-0.86, quartzy 0.4-0.45, white clay 0.7-0.73, silicon sol 0.3-0.4, pregelatinized Starch 0.2-0.23, impurity≤0.01.

2. the automobile component cast steel material of a kind of resistance to elevated temperatures excellence 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, carbon, silicon metal 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) mix with white clay, calcium silicide after quartz being broken into small-particle, put into ball mill ball milling 90 minutes, after taking-up, add the water of total amount 2 times amount, silicon sol, sonic oscillation leaves standstill after 40 minutes and filters, filter cake is dried under the condition of 100 DEG C, crosses 400 mesh sieves, obtain mixed powder; Pregelatinized Starch is added in the water of 3 times amount, after being heated to while stirring to dissolve completely and mixed powder jointly send in tablets press, stir extruding pelletization after 15 minutes, particle is sent into baking oven to send in sintering oven with 8 DEG C/min of ramp to 480 DEG C after dry 30 minutes with the temperature of 120 DEG C, sinter 90 minutes, 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.