Q&P steel plate with high strength-elongation product and excellent welding performance and preparing method thereof

Abstract

The invention discloses a Q&P steel plate with the high strength-elongation product and excellent welding performance and a preparing method thereof, and belongs to the technical field of cold-rolledsteel production of automobiles. The steel plate comprises the following chemical components of, in percentage by mass, 0.17%-0.21% of C, 1.80%-2.20% of Si, 2.10%-2.40% of Mn, 0.03%-0.05% of Nb, 0.008%-0.020% of Ti, 0.025%-0.045% of Als, less than or equal to 0.020% of P, less than or equal to 0.0030% of S, and the balance Fe and inevitable residual impurities. The preparing method comprises the steps of steel-making, continuous casting, hot rolling, acid pickling, cold rolling and continuous annealing. The Q&P steel has the characteristic of excellent mechanical property, the yield strength greater than or equal to 600 MPa, the tensile strength greater than or equal to 1000 MPa, the elongation percentage greater than 20%, and the strength-elongation product greater than or equal to 22GPa%. According to the Q&P steel plate with the high strength-elongation product and excellent welding performance and the preparing method thereof, the Q&P steel with the high strength-elongation productcan be obtained at a relatively low partitioning temperature, and the requirement for process equipment is low, thus being suitable for the production of an existing continuous annealing production line.

Description

[0001] Technical field: [0002] The invention belongs to the technical field of cold-rolled automobile steel production, and in particular relates to a high-strength plastic Q&P steel plate with excellent welding performance and a preparation method thereof. [0003] Background technique: [0004] In the past two decades, with the rapid development of the automobile industry, the proportion of pollution caused by automobile exhaust has also increased, which has brought enormous pressure to the current energy and environment. Automobile energy saving and emission reduction has become an imminent and important issue, and has been widely concerned by people day by day. At present, many countries and regions in the world have formulated energy-saving and emission-reduction targets. my country has also made it clear that by 2020, the average fuel consumption of new passenger cars will reach 5L / 100km. The pressure is high. Among the many current energy-saving and emission-reduction...

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Problems solved by technology

[0009] Aiming at the above-mentioned deficiencies existing in the existing Q&P steel and its preparation process, the present invention provides a high-strength plasticity cold-rolled 1000MPa grade Q&P steel plate with excellent welding performance suitable for the existing traditional continuous annealing process equipment and its preparation method

Through the effective combination of technology and alloy elements, the present invention controls the whole process of the structure, so that it can obtain a higher strength and plastic product at a relatively low partition temperature, and solves the problem of no rapid induction heating distribution in the existing traditional continuous annealing production line ; At the same time, through low-carbon, Nb+Ti micro-alloy design, solve the welding problem of Q&P steel

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