| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hot-rolled steel sheet which has a tensile strength (TS) of 540 MPa or more, excellent processability and excellent stability of material quality and which can be used for the production of a cold-rolled steel sheet and the production of a hot-dipped galvanized steel sheet, and to provide a method for producing the hot-rolled steel sheet. <P>SOLUTION: The component composition of this hot-rolled steel sheet for a cold-rolled steel sheet superior in processability and material stability contains, in mass%, 0.04-0.20% C, 0.7-2.3% Si, 0.8-2.8% Mn, 0.1% or less P, 0.01% or less S, 0.1% or less Al and 0.008% or less N, with the balance made up of Fe and unavoidable impurities. The structure of this hot-rolled steel sheet contains ferrite and pearlite. The ferrite has an area ratio of 75% or more and an average crystal grain size of 5-25 μm. The pearlite has an area ratio of 5% or more, an average crystal grain size of 2.0 μm or more, and a mean free path of 5 μm or more. <P>COPYRIGHT: (C)2013,JPO&INPIT |
