Production method of cold-rolled martensite steel plate with good bending performance and ultra-high strength

Abstract

The invention relates to a production method of a cold-rolled martensite steel plate with good bending performance and ultra-high strength. Chemical components of the steel plate comprise, by mass percent, 0.21%-0.22% of C, 0.3%-0.4% of Si, 1.6%-1.7% of Mn, 0.02%-0.07% of Al, smaller than or equal to 0.02% of P, smaller than or equal to 0.005% of S, smaller than or equal to 0.005% of N, and the balance Fe and inevitable impurity. The tensile strength of the steel plate is larger than 1600 MPa, the extending rate is larger than 6%, and 100% tempered martensite texture is adopted as metallographic texture. According to the method, on the basis of adding basis elements such as C, Si and Mn in a reduction manner and not adding other rare alloy elements, the equipment ability of an existing high-strength continuous annealing unit is fully utilized, the cold-rolled martensite steel plate with the level over 1600 MPa and good bending performance is developed, the strength meets the requirement of the national standard, and in addition, the extending rate is higher than the requirement of the national standard.

Description

technical field [0001] The invention relates to the technical field of cold-rolled steel plate production, in particular to a production method of an ultra-high-strength cold-rolled martensitic steel plate with good bending properties. Background technique [0002] In recent years, driven by the demand for weight reduction of automobile bodies, the pace of high-strength reinforcement of body structural parts is getting faster and faster. Because of its high strength, cold-rolled martensitic steel plate has been used more and more in the manufacture of automotive structural parts, although its plasticity is limited, mainly through rolling processing to manufacture body structural parts such as bumpers and door sill reinforcements . [0003] The market's requirements for steel sheets for automobiles all have a common feature, which is to pursue the lowest cost on the premise of meeting the performance requirements. At present, there are very few iron and steel enterprises in...

AI Technical Summary

Problems solved by technology

At present, there are very few iron and steel companies in the world that can produce martensitic steel products with a strength above 1600MPa, and the current mainstream technology for this level of martensitic steel is to add certain strengthening rare alloys or a large number of alloying elements, resulting in high production costs

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