| abstract |
This hot-rolled steel sheet comprises, in mass%, C: 0.030% to less than 0.075%, Si+Al: 0.08%-0.40%, Mn: 0.5%-2.0%, and Ti: 0.020%-0.150%, and has a metal structure comprising ferrite and martensite. In said metal structure, in area%, 90%-98% is ferrite, 2%-10% is martensite, 0%-3% is bainite, and 0%-3% is pearlite. In the martensite, the number fraction of martensite grains with a hardness of at least 10.0 GPa is 10% or less. The ratio N1/N2 of the number N1 of martensite grains with a hardness of 8.0 GPa to less than 10.0 GPa with respect to the number N2 of martensite grains with a hardness of less than 8.0 GPa is 0.8-1.2. |