CORROSION-RESISTANT SINTERED ALLOY STEELS AND METHOD FOR MAKING SAME

摘要

It is provided a method for the manufacture of a corrosion-resistant sintered alloy steel, which comprises providing a stainless steel powder; adding a binder to said steel powder; molding the mixture; and carrying out the steps of (1) heating the resultant molding to remove the binder therefrom, (2) sintering the thus debound molding under reduced pressure up to 30 Torr, and (3) further sintering at a higher temperature than those of steps (1) and (2) in a non-oxidative atmosphere under substantially atmospheric pressure. It is also provided a corrosion-resistant sintered alloy steel which comprises a stainless steel, said alloy steel having a density ratio of not less than 92%, a maximum diameter of pore present in the structure of not larger than 20 .mu.m, and a content of Cr at the surface of the steel as being sintered which is not less than 80% of a content of Cr in the inside thereof.