1180MPa-grade high-plasticity high-hole-expansion steel and manufacturing method thereof

Abstract

The invention discloses 1180MPa-grade high-plasticity high-hole-expansion steel and a manufacturing method thereof. The 1180MPa-grade high-plasticity 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 yield strength of the high-reaming steel is larger than or equal to 900 MPa, the tensile strength is larger than or equal to 1180 MPa, meanwhile, the high-reaming steel has good ductility (transverse A50 is larger than or equal to 10%), cold bending performance (d is smaller than or equal to 4a and 180 degrees) and reaming performance (the reaming rate is larger than or equal to 30%), and the high-reaming steel can be applied to passenger car chassis parts such as control arms and auxiliary frames needing high-strength thinning.

Description

technical field [0001] The invention relates to the field of high-strength steel, in particular to a 1180MPa-grade high-plasticity 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 regulation...

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.

Higher strength level such as 1180MPa high hole expansion steel has not yet been developed by manufacturers

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