Method for manufacturing stainless steel product by nitrogen absorption treatment and stainless steel product produced by the method

Abstract

A method for manufacturing a stainless steel product, which comprises contacting a bulk product of a ferritic stainless steel having been formed into a desired shape through melting with an inert gas containing nitrogen at 800° C. or higher, to thereby convert the structure of the whole or a part of the bulk product to austenite and produce an austenitic product or a product having a two-phase structure comprised of ferrite and austenite, respectively. The method allows the reduction of the manufacturing cost of a formed austenitic stainless steel product to a satisfactorily low level, which results in the manufacture of a stainless steel product having satisfactory characteristics in both of strength and corrosion resistance at a satisfactorily low cost.

1 . A manufacturing process of a stainless steel product by nitrogen absorption treatment, comprising the steps of bringing a bulk product of ferritic stainless steel made by melting, forming and machining into a desired shape, into contact with an inert gas containing nitrogen at or above 800° C., and austenitizing the product completely.  
   
   
       2 . A stainless steel product having a completely austenitic structure formed by adding nitrogen through contact with an inert gas containing nitrogen, to a bulk product of ferritic stainless steel made by melting, forming and machining into a desired shape.  
   
   
       3 . (canceled)