Patent ID: 8673093
Filing Date: 2014-03-18
Classification: C21D,C22C

Abstract:
1. A hot-rolled steel sheet for cold-rolling, comprising, in mass %: C: 0.10-0.25%, Si: 0.5-3%, Mn: 1.0-3.2%, P: 0.1% or below, S: 0.05% or below, Al: 0.01-0.1%, Mo: 0.02% or below, Ti: 0.005-0.1%, B: 0.0002-0.0030%, N: 0.01% or below, iron and inevitable impurities; wherein the hot-rolled steel sheet has a value Z calculated by an equation (1) below of 2.0-6.0, and a tensile strength of 900 MPa or below wherein where [ ] represents a content (mass %) of the respective elements contained in the hot-rolled steel sheet.