HIGH-STRENGTH STEEL SHEET AND METHOD FOR PRODUCING THE SAME

摘要

Provided are a high-strength steel sheet and a method for producing the same. A high-strength steel sheet has a composition containing 0.10% to 0.18% C, more than 0.5% to 1.5% Si, 0.5% to 1.5% Mn, 0.05% or less P, 0.005% or less S, and 0.05% or less Al on a mass basis, the remainder being Fe and inevitable impurities and also has a microstructure containing ferrite and pearlite. The volume fraction of the ferrite is 70% to 97%. The volume fraction of the pearlite is 3% or more. The volume fraction of cementite present at grain boundaries of the ferrite is 2% or less. The sum of the volume fractions of phases other than the ferrite, the pearlite, and the cementite is less than 3%. The average grain size of the ferrite is 7 μm or less.

主权项

1. A high-strength steel sheet having a composition containing 0.10% to 0.18% C, more than 0.5% to 1.5% Si, 0.5% to 1.5% Mn, 0.05% or less P, 0.005% or less S, and 0.05% or less Al on a mass basis, the remainder being Fe and inevitable impurities, the high-strength steel sheet having a microstructure containing ferrite and pearlite, wherein the volume fraction of the ferrite is 70% to 97%, the volume fraction of the pearlite is 3% or more, the volume fraction of cementite present at grain boundaries of the ferrite is 2% or less, the sum of the volume fractions of phases other than the ferrite, the pearlite, and the cementite is less than 3%, and the average grain size of the ferrite is 7 μm or less.