| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin steel sheet which has high strength tensile of TS:1180 MPa or more, and which is excellent in moldability and hydrogen embrittllement resistance, and its production method.SOLUTION: A substrate is a thin steel sheet which includes C:0.10% or more in mass %, and which has a hardness of 350 HV in Vickers hardness. A sedimentary layer is formed in a cold spray method on at least one surface of the substrate. Thereby, a soft sedimentary layer of a thickness 10 to 500 μm for each face with porosity less than 10% in mass%, having composition composed of a remainder Fe and inevitable impurity, which satisfies C:less than 0.10% im mass%, or Mneq:less than 2.5 of other alloy elements, and ductility is substantially improved in a whole thin sheet, in the thin steel sheet which is excellent in moldability and hydrogen embrittlement resistance, and which has high strength of TS:1180MPa or more, and TS×El is 16000MPa% or more. |
