HOT ROLLED STEEL SHEET HAVING EXCELLENT CORROSION RESISTANCE AFTER ELECTRODEPOSITION COATING AND ITS PRODUCTION METHOD

PROBLEM TO BE SOLVED: To provide a hot rolled steel sheet having excellent corrosion resistance after electrodeposition coating, and to provide its production method. SOLUTION: The hot rolled steel sheet having excellent corrosion resistance after electrodeposition coating is characterized in that, upon the observation of the cross-section in a steel sheet having a composition comprising, by mass, 0.015 to 0.08% C, ≤1.5% Si, 0.1 to 2.5% Mn, ≤0.015% P, ≤0.015% S, 0.01 to 0.08% Al, ≤0.009% N and 0.05 to 0.2% Ti, and in which the following A value lies in the range of 0 to 0.06, and the balance inevitable impurities, carbides with the longest diameter of ≥0.05 μm are present by 10 to 150 pieces in the the cross-sectional range at a depth of 1 μm and a length of 100 μm from the outermost surface part of the steel sheet. The production method of the same is provided. Wherein, the A value is C-(Ti/5.5), and C and Ti are the mass% of the respective elements. COPYRIGHT: (C)2006,JPO&NCIPI