High-toughness hot-rolled 530 MPa-grade automobile cold stamping bridge shell steel plate and manufacturing method thereof

Abstract

The invention discloses a high-toughness hot-rolled 530 MPa-grade automobile cold stamping bridge shell steel plate and a manufacturing method thereof. The high-toughness hot-rolled 530 MPa-grade automobile cold stamping bridge shell steel plate comprises the following components of C, S, Mn, P, S, Al, Nb, Ti and the balance Fe and impurities; the content of the elements has to meet the followingrelationship at the same time, Nb+Ti is greater than or equal to 0.025% and is less than or equal to 0.045%, CEV is equal to C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15 and is less than or equal to 0.45%; the manufacturing method is characterized in that V is not added to the component design, Mn content is properly adjusted, a certain amount of Si, Nb, Ti and the like are added, molten iron pretreatment, molten steel smelting, continuous casting, cooling, heating, rolling, cooling, finishing, inspection and the like are carried out, so that the surface quality and strength of the steel meet the cold stamping and welding processing processes of the bridge shell steel; the yield strength ReL of the steel plate is greater than or equal to 375 MPa, the tensile strength Rm is greater than or equal to 530 MPa, the elongation percentage A after fracture is greater than or equal to 26%, the impact power KV2 at 0 DEG C is greater than or equal to 180 J, the grain size is 8-10 grades, the strip-shaped gradeis 1-3 grades, and cold stamping and forming of 10-16 mm specifications can be realized.

Description

technical field [0001] The invention relates to the technical field of manufacturing automobile axle housing steel plates, in particular to a high-toughness hot-rolled 530MPa grade automotive cold-stamped axle housing steel plate and a manufacturing method thereof. Background technique [0002] The automobile axle is one of the key parts of the automobile. It is not only a part of the transmission system, but also an important part of the driving system. As the main part of the axle, the automobile axle housing is a key component to ensure the normal operation and service life of the automobile, so it has high requirements for its mechanical strength, toughness and fatigue resistance. The production cost of the axle housing accounts for about 30% of the total cost of the drive axle. Especially when heavy-duty vehicles are working due to harsh roads and working conditions, the axle housing is subjected to strong impact loads, and the quality requirements for the axle housing...

AI Technical Summary

Problems solved by technology

In addition, changes in the internal structure of the steel plate after thermal processing cause performance fluctuations, which increase product safety hazards to a certain extent

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