An exterior stainless steel sheet is provided comprising a stainless steel substrate and a coating layer formed on one surface of the steel substrate from Al, Al alloy, Zn or Zn alloy to a thickness of 0.1 to 70 .mu.m, preferably 1 to 70 .mu.m. A Zn or Zn-Ni alloy plated stainless steel strip is prepared by degreasing a stainless steel strip, substantially activating the surface of the strip, and electroplating the strip in a zinc or zinc-nickel alloy plating bath at pH 3.5 or lower. During electroplating of one side, the other side of the strip not to be plated is covered with a protective film. A stainless steel sheet comprising a stainless steel substrate and a coating layer formed on one surface of the steel substrate from Zn or Zn alloy to a thickness of 0.1 to 50 .mu.m, preferably 1 to 50 .mu.m is useful in preparing welded pipes.