CN105463297A - Cast steel axle housing for heavy truck - Google Patents

Abstract

The invention discloses a cast steel axle housing for a heavy truck. An axle housing material is prepared from, by weight, 95-98 parts of waste steel (the iron content is not smaller than 98%), 2-3 parts of Z18 pig iron, 0.22-0.25 part of carbon, 0.4-0.45 part of crystal silicon, 0.9-1.1 parts of manganese, 0.2-0.23 part of chromium, 0.1-0.12 part of molybdenum, 0.2-0.25 part of vanadium, 0.8-0.86 part of calcium silicide, 0.6-0.65 part of nano graphite powder, 0.2-0.25 part of polyvinyl alcohol, 0.4-0.43 part of bentonite and not larger than 0.01 part of impurities. The waste steel serves as a main iron base material, and meanwhile an appropriate number of other metal components are added in a matching manner; and a made cast steel material is high in mechanical performance, good in low-temperature impacting toughness, good in casting and machining process performance and particularly suitable for axle housings of heavy trucks for carrying cargoes and the like.

Description

A kind of cast-steel axle shell of heavy lorry

Technical field

The present invention relates to cast material technical field, particularly relate to a kind of cast-steel axle shell of heavy lorry.

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 cast-steel axle shell of heavy lorry.

The present invention is achieved by the following technical solutions:

A kind of cast-steel axle shell of heavy lorry, this axle housing material 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, carbon 0.22-0.25, silicon metal 0.4-0.45, manganese 0.9-1.1, chromium 0.2-0.23, molybdenum 0.1-0.12, vanadium 0.2-0.25, calcium silicide 0.8-0.86, Nano graphite powder 0.6-0.65, polyvinyl alcohol 0.2-0.25, wilkinite 0.4-0.43, impurity≤0.01.

Described a kind of cast-steel axle shell of heavy lorry, this axle housing material 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) calcium silicide is mixed with wilkinite, put into ball mill for dry grinding 40 minutes, mix with Nano graphite powder after crossing 200 mesh sieves, form mixed powder; Polyvinyl alcohol is added in the water of 3 times amount, be heated to 60 DEG C while stirring and form solution to dissolving completely; Mixed powder is sent in tablets press, adds polyvinyl alcohol solution, stirs extruding pelletization after 15 minutes, particle is sent into baking oven to send in sintering oven with 10 DEG C/min of ramp to 450 DEG C after dry 30 minutes with the temperature of 100 DEG C, sinter 2 hours, take out and be cooled to room temperature, obtain 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.

The present invention adopts steel scrap as main iron, and coordinate simultaneously and add other metal ingredients appropriate, the cast steel material mechanical property made is high, and low-temperature impact toughness is good, casting, process industrial art performance are good, is specially adapted to the heavy-duty car axle housings such as loading.

Embodiment

A kind of cast-steel axle shell of heavy lorry, this axle housing material 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, carbon 0.22, silicon metal 0.4, manganese 0.9, chromium 0.2, molybdenum 0.1, vanadium 0.2, calcium silicide 0.8, Nano graphite powder 0.6, polyvinyl alcohol 0.2, wilkinite 0.4, impurity≤0.01.

Described a kind of cast-steel axle shell of heavy lorry, this axle housing material 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) calcium silicide is mixed with wilkinite, put into ball mill for dry grinding 40 minutes, mix with Nano graphite powder after crossing 200 mesh sieves, form mixed powder; Polyvinyl alcohol is added in the water of 3 times amount, be heated to 60 DEG C while stirring and form solution to dissolving completely; Mixed powder is sent in tablets press, adds polyvinyl alcohol solution, stirs extruding pelletization after 15 minutes, particle is sent into baking oven to send in sintering oven with 10 DEG C/min of ramp to 450 DEG C after dry 30 minutes with the temperature of 100 DEG C, sinter 2 hours, take out and be cooled to room temperature, obtain 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. a cast-steel axle shell of heavy lorry, it is characterized in that, this axle housing material 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, carbon 0.22-0.25, silicon metal 0.4-0.45, manganese 0.9-1.1, chromium 0.2-0.23, molybdenum 0.1-0.12, vanadium 0.2-0.25, calcium silicide 0.8-0.86, Nano graphite powder 0.6-0.65, polyvinyl alcohol 0.2-0.25, wilkinite 0.4-0.43, impurity≤0.01.

2. a kind of cast-steel axle shell of heavy lorry according to claim 1, it is characterized in that, this axle housing material 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) calcium silicide is mixed with wilkinite, put into ball mill for dry grinding 40 minutes, mix with Nano graphite powder after crossing 200 mesh sieves, form mixed powder; Polyvinyl alcohol is added in the water of 3 times amount, be heated to 60 DEG C while stirring and form solution to dissolving completely; Mixed powder is sent in tablets press, adds polyvinyl alcohol solution, stirs extruding pelletization after 15 minutes, particle is sent into baking oven to send in sintering oven with 10 DEG C/min of ramp to 450 DEG C after dry 30 minutes with the temperature of 100 DEG C, sinter 2 hours, take out and be cooled to room temperature, obtain 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.