Steel sheet and method for manufacturing the same

摘要

The method for manufacturing steel sheet comprises the steps of: rough-rolling to form a sheet bar; finish-rolling the sheet bar to form a steel strip; applying primary cooling and secondary cooling to the finish-rolled steel strip; and coiling the secondary-cooled steel strip. The primary cooling is conducted at cooling speeds of 120° C./sec or more down to the temperatures of from 500 to 800° C. The secondary cooling is conducted at cooling speeds of less than 60° C./sec.