| 摘要 |
PROBLEM TO BE SOLVED: To provide a transformation-induced plastic plated steel sheet having tensile strength of 440 to 500 MPa, in which the product of the above tensile strength TS (unit; MPa) and uniform elongation UE (unit; %) also satisfies the following inequality, excellent in a balance of strength-ductility and further excellent in adhesion for plating: TS×UE>=11,000...(1). SOLUTION: By mass, 0.06 to 0.18% C, 0.5 to 3% Mn, <=0.5% (inclusive of 0%) Si and <=3% (not inclusive of 0%) area satisfied, the volume ratio of residual austenite in the steel is >=2%, and also, the X-ray diffraction intensities of Mn and Al in the residual austenitic crystal grains are allowed to satisfy the relations in the following inequalities (2) and (3): Iγ(Mn)/Iα(Mn)>1.2...(2), and Iγ(Al)/Iα(Al)>0.8...(3).
|
