980MPa-grade tempered martensite type high-hole-expansion steel and manufacturing method thereof

Abstract

The invention discloses 980MPa-grade tempered martensite type high-hole-expansion steel and a manufacturing method thereof. The 980MPa-grade tempered martensite type high-hole-expansion steel comprises the following chemical components in percentage by weight: 0.06-0.10% of C, 0.8-2.0% of Si, 1.5-2.0% of Mn, less than or equal to 0.02% of P, less than or equal to 0.003% of S, 0.02-0.08% of Al, less than or equal to 0.004% of N, 0.1-0.5% of Mo, 0.01-0.05% of Ti, less than or equal to 0.0030% of O and the balance of Fe and other inevitable impurities. The high-reaming steel has excellent ultrahigh strength, plasticity and toughness matching and good reaming and flanging performance, the yield strength of the high-reaming steel is larger than or equal to 800 MPa, the tensile strength of the high-reaming steel is larger than or equal to 980 MPa, the ductility (transverse A50 is larger than or equal to 10%), the impact toughness and the reaming performance (the reaming rate is larger than or equal to 40%), and the high-reaming steel can be applied to manufacturing of automobile chassis, auxiliary frames and other parts needing high-strength thinning and reaming and flanging. Wide application prospects are realized.

Description

technical field [0001] The invention belongs to the field of high-strength steel, in particular to a 980MPa tempered martensitic high-hole expansion steel and a manufacturing method thereof. Background technique [0002] With the development of the national economy, the production of automobiles has also increased significantly, and the use of plates has continued to increase. The original design of parts of many models in the domestic automobile industry requires the use of hot-rolled or pickled plates, such as chassis parts, torsion beams, sub-frames of cars, wheel spokes and rims, front and rear axle assemblies, body structural parts, seats , Clutches, seat belts, truck box panels, protective nets, automotive beams and other spare parts. Among them, chassis steel accounts for 24-34% of the total steel consumption of cars. [0003] The lightweight of passenger cars is not only a development trend in the automotive industry, but also a requirement of laws and regulations....

AI Technical Summary

Problems solved by technology

The 980MPa high-hole expansion steel is still in the stage of R&D and certification, and has not yet reached the stage of mass use.

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