Automotive low-carbon aluminum-killed steel sheet and production method thereof

Abstract

The invention discloses an automotive low-carbon aluminum-killed steel sheet and a production method thereof and belongs to the technical field of steel sheets and a processing method thereof. The steel sheet which is low in yield strength and high in percentage of elongation chemically comprises, by mass, 0.02-0.03% of C, 0.1-0.2% of Mn, not more than 0.025% of Si, not more than 0.015% of P, not more than 0.015% of S, 0.03-0.04% of Als, 0.0020-0.0040% of N and the balance Fe. The content of the C in chemical components of the steel sheet is 0.02-0.03% and is relatively low, and the content of Fe3C and pearlites in a substrate can be reduced, so that the yield strength of the steel sheet can be effectively lowered. The production method of the steel sheet is not only beneficial to lowering of the yield strength of the steel sheet but also beneficial to increase of the percentage of elongation, and ageing resistance of the steel plate is improved.

Description

technical field [0001] The invention relates to the technical field of steel plates and processing methods thereof, in particular to a low-carbon aluminum-killed steel plate for automobiles with low yield strength and high elongation and a production method thereof. Background technique [0002] Low-carbon aluminum-killed steel plates are often produced by bell annealing, which are mostly used in the automotive industry, home appliance industry, and construction fields. According to the requirements of GB / T 5213-2001 for similar steel types, its composition is: C, ≤0.08%; Mn, ≤0.4%; Si, ≤0.03%; P, ≤0.020%; S, ≤0.025%; Als, 0.02-0.07%, the balance being Fe. The national standard requires the yield strength to be ≤240MPa, the tensile strength to be 270-350MPa, n90≥1.8, r90≥1.6. In the European standard EN 10130-2006, the composition requirements are C, ≤0.12%; Mn, ≤0.60%; S, ≤0.45%; P, ≤0.045%, and the thickness specification is 0.6~1.0mm. The performance requirement is that ...

AI Technical Summary

Problems solved by technology

For this type of steel, the content of elements such as C and Mn is usually controlled to meet the requirements of tensile strength, which often leads to an increase in yield strength, an increase in yield ratio (the ratio of yield strength to tensile strength), and a decrease in r value, which is not conducive to Press forming of automotive sheet

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