Patent ID: 7960035

Claim:
A hot rolled steel sheet characterized in that a maximum depth (Ry) of pits and bumps, existing on a surface thereof, is not less than 10 μm, an average interval (Sm) of the pits and the bumps is not more than 30 μm, and a load length ratio (tp40) of the pits and the bumps on the surface is not more than 20%; wherein the hot rolled steel sheet contains C ranging from 0.03 to 1.0 mass %, Si not more than 2.0 mass % (including 0 mass %), Mn ranging from 0.3 to 4.0 mass %, Al ranging from 0.001 to 0.5 mass %, Mo not more than 1.0 mass % (including 0 mass %), and Cr not more than 1.5 mass % (including 0 mass %).