340MPa-grade high-strength cold-rolled steel plate used for deep-drawing, and production method thereof

Abstract

The invention relates to a 340MPa-grade high-strength cold-rolled steel plate used for deep-drawing, and a production method thereof. The steel plate comprises the components of, by mass: no more than 0.010% of C, no more than 0.060% of Si, 0.30%-0.70% of Mn, 0.030%-0.070% of P, no more than 0.015% of S, 0.020%-0.080% of Als, no more than 0.0050% of N, 0.0002%-0.0012% of B, and balance of Fe and inevitable impurities. A production method of the steel plate is that: a middle-ladle temperature is controlled at a value 20-60 DEG C higher than a liquidus temperature; a furnace discharging temperature is 1150-1250 DEG C; a final rolling temperature is 850-950 DEG C; a coiling temperature is 650-750 DEG C; and a cold rolling total reduction rate is controlled at 50-80%. In a continuous annealing process, a soaking temperature is 750-850 DEG C; an annealing temperature is 600-700 DEG C; and a flash cooling temperature is 350-450 DEG C.

Description

technical field [0001] The invention relates to the field of metal materials, and relates to the continuous annealing process of steelmaking, hot rolling and cold rolling of metal plates (strips), in particular to a high-strength cold-rolled steel plate for 340MPa deep drawing and a production method thereof. Background technique [0002] In recent decades, the production of automobiles (especially cars) has developed rapidly in the world's major industrialized countries. Since the 1990s in my country, the automobile industry has developed rapidly. According to my country's national economic development plan, the development trend of the automobile industry and the development of the "Eleventh Five-Year Plan" automobile industry, especially the development in the past two years, it is predicted that by the end of my country's "Eleventh Five-Year Plan" in 2010, the number of automobiles will reach 8 million. The average annual growth rate is about 10-15%, of which there are a...

AI Technical Summary

Problems solved by technology

The rapid development of the automobile industry has produced two main problems: first, the number of automobiles has increased and the speed of vehicles has increased. In order to ensure the safety of personnel and vehicles, automotive structural parts are required to have high strength, high crush absorption capacity and high impact resistance; The second question is how to reduce driving fuel consumption and save energy

[0005] These two invention steels can meet the requirements of deep drawing formability for the manufacture of high-strength steel plates, but there are some shortcomings: 1) C and Si content are high, which is not conducive to deep drawing; 2) Some Nb elements are added, and the cost is high

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