| 摘要 |
As to a steel composition, in this invention, Si content is regulated to a given range and Nb and Cu or Ni, Mo are compositively added, and a recrystallization annealing is carried out to form an internal oxide layer just beneath a surface of a steel sheet and a surface oxide simultaneously formed on the surface of the steel sheet is removed by pickling. As a result, the formation of oxides of Si, Mn and the like is considerably decreased on the surface of the steel sheet in a subsequent heating before plating because the above internal oxide layer acts as a diffusion barrier. <??>Thus, according to the invention, there can be obtained high tensile strength hot-dipped steel sheets having a considerably excellent plating property. |
