Production method of low-earing-rate extra-deep-drawing cold-rolling annealing low-carbon steel strip

Abstract

The invention discloses a production method of a low-earing-rate extra-deep-drawing cold-rolling annealing low-carbon steel strip. The production method comprises the processes of smelting, continuouscasting, hot rolling, cold rolling and continuous annealing; as for the hot rolling process, after each pass of rough rolling, stopping is conducted for 20-30 s, the final rolling temperature of finish rolling is 860-880 DEG C, and the coiling temperature is 720-740 DEG C; and as for the cold rolling process, the cold rolling compression ratio is 62-83%. The production method is suitable for production of the high-quality deep-drawing low-carbon steel strip by a conventional continuous rolling production line and an annealing line, the 90% super-high cold rolling reduction rate is not needed,and the advantage that production is easy to control is achieved; and the cold-rolling annealing low-carbon steel strip has the product performance: the yield strength is 110-150 MPa, the tensile strength is 290-325 MPa, the elongation A80 is 40-60%, r90 is 2.80-3.3, and the finished earing rate delta r value is less than or equal to 0.60.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a production method of an ultra-deep drawing cold-rolled annealed low-carbon steel strip with a low selvage rate. Background technique [0002] In recent years, my country's automobile industry has entered a stage of rapid development, which puts forward higher requirements for the quality of automobile steel. In the process of automobile production, the material waste caused by the large punching and pressing rate is not conducive to reducing production costs. [0003] The r and △r values ​​are important indicators to measure the formability of the auto sheet. The larger the r value, the better the stamping deformation ability of the auto sheet, and the smaller the absolute value of △r, the lower the ear forming rate. A large number of studies have shown that by adding Ti or Nb elements to reduce the solid solution C element content in the steel plate matrix, col...

AI Technical Summary

Problems solved by technology

However, in actual industrial production, there are very few conventional continuous rolling mills with a cold rolling reduction rate of 85% to 90%, which limits the industrialized mass production of cold-rolled low-carbon steel sheets with low lug production rates.