High-strength plastic-laden low-carbon silicon-manganese q&p steel plate and its preparation method by asynchronous rolling

Abstract

The invention discloses a high strength-plasticity product low carbon silicon-manganese system Q&P steel plate and an asymmetrical rolling preparation method. The steel plate comprises, by mass percent, 0.18%-0.23% of C, 1.40%-1.60% of Mn, 1.30%-1.60% of Si, 0.10%-0.20% of Al, 0.02%-0.06% of Nb, smaller than 0.01% of S, smaller than 0.01% of P and the balance Fe and inevitable impurities. The thickness ranges from 3.0 mm to 4.5 mm. The method comprises the steps that (1) smelting is carried out according to the compositions of Q&P steel, and forging is carried out after a blank is forged to obtain a plate blank; (2) the plate blank is heated and subjected to heat preservation, and after asymmetrical rolling is carried out, air cooling is carried out to room temperature to obtain a rolled steel plate; and (3) after being subjected to heat preservation at the temperature of a two-phase area, the rolled steel plate is quenched to be subjected to heat preservation in a martensite transformation area, the temperature is raised to distribution temperature for distribution, and air cooling is carried out to room temperature to obtain the Q&P steel plate. The Q&P steel plate is of a mixed multiphase structure of martensite, ferrite and retained austenite, the yield strength of the Q&P steel plate ranges from 510 MPa to 640 MPa, the tensile strength of the Q&P steel plate ranges from 720 MPa to 860 MPa, the elongation of the Q&P steel plate ranges from 38% to 44%, the strength-plasticity product of the Q&P steel plate ranges from 27600 MPa.% to 34700 MPa.%.

Description

technical field [0001] The invention belongs to the field of material processing, and in particular relates to a high-strength plastic product low-carbon silicon-manganese Q&P steel plate and a preparation method of asynchronous rolling. Background technique [0002] While automobiles bring convenience to people, they also bring many problems such as traffic congestion and environmental pollution. Therefore, the development of "environmentally friendly vehicles" characterized by low fuel consumption and low emissions has become a future development trend. Statistics show that every 10% reduction in the quality of the car itself can save 3% to 7% of fuel. Therefore, the weight reduction of automobiles is an important way to reduce fuel consumption, and it is of great significance to energy saving and environmental improvement. Automobile lightweight has become the development trend of the advanced automobile industry, which brings challenges to the research and development ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem in the prior art that improving the mechanical properties of Q&P steel is mainly concentrated in the heat treatment stage, the present invention provides a high-strength plasticity low-carbon silicon-manganese series Q&P steel plate and a preparation method of asynchronous rolling. The asynchronous rolling method is adopted in the rolling stage, the purpose is to effectively refine the grains through asynchronous rolling, and produce low-carbon silicon-manganese Q&P steel with high strength and plastic product

Images