TH2001003681A - High-strength cold-rolled steel plates and methods for producing this - Google Patents

Abstract

The fabrication summary, which appears on the advertisement page ReadFile:DEPCT64, provides a high strength cold-rolled steel sheet with tensile strength of 980 MPa or greater, excellent toughness and low damage rate. In the hole expansion test and methods for producing the same, high strength cold rolled steel plates are combined with a pre-defined alloy where the total area ratio of ferrite and binitic ferrite is 20. Percent or more and 80% or less, area ratio of residual austenite greater than 10% and 40% or less, area ratio of temper martensite greater than 0% and 50% or less. than, the ratio of residual austenite with characteristic ratio of 0.5 or less to residual austenite of 75% or more in area ratio; A characteristic ratio of 0.5 or less that appears in the ferrite grain region with a orientation difference of 40 degrees or more to residual austenite with a characteristic ratio of 0.5 or less of 50 percent or more in the ratio. floor and the mean KAM value of the bcc cycle is 1 degree or less --------------------------------- --------------------------

Claims (3)

Claims (item one) which will appear on the advertisement page:DEPCT64 1. High-strength cold-rolled steel sheet consisting of: alloy containing in percent by mass content of C: greater than 0.15 percent and 0.45 percent or less, Si: 0.5 percent or more and 2.5 percent or less, Mn: 1.5 percent or more, and 3.0 percent or less, P:0.05 percent or less, S:0.01 percent or less, Al:0.01 percent or less