| 摘要 |
PURPOSE:To manufacture a dispersion-plated steel sheet having high corrosion resistance and superior pitting resistance by coating the surface of a steel sheet with a two-layered coat consisting of a Zn or Zn alloy layer formed as a lower layer by plating and a Zn or Zn alloy layer contg. fine particles of a specified compound formed as an upper layer by plating. CONSTITUTION:One side or both sides of a steel sheet for an automobile body or the like are plated with Zn or a Zn alloy contg. 30-95wt% fine particles of oxides, carbides, nitrides, borides, phosphides or sulfides of one or more kinds of elements such as Si, Al, Fe, Ti, Mo, Cu, Zn, Ni, Co, La, Ce and B to form an upper layer. The average particle size of the fine particles is <=5mum. A layer of Zn or a Zn alloy contg. 0.3-80% Ni, Co, Cr, Fe, Mn, Tl, Ce or the like is interposed as a lower layer by plating between the steel sheet and the upper layer to obtain a steel sheet having a two-layered coat. This steel sheet is a diffusion-plated steel sheet having high corrosion resistance and superior pitting resistance. |
