Many kinds of stainless steels were developed for the usage in each industrial field. The research and development on stainless steel in these 30 years were described. A new refining process of stainless steel made it possible to reduce an impurity element to extra low contents, and to develop new stainless steels, e. g., many kinds of ferritic stainless steels. Furthermore, many of these stainless steels were standardized to the Japanese Industrial Standard.
Super stainless steel with high corrosion resistance was developed as a roof material at a seaside area. New ferritic stainless steels with high thermal fatigue resistance were adopted to an automobile as an exhaust manifold. The suitable alloys from 13Cr stainless steel to high-alloyed steel were developed for tubings of oil and gas wells where the corrosion resistance largely depends on the contents of CO₂ and/or H₂S. Many corrosion problems occurred in a commercial nuclear power plant. The new corrosion phenomena were studied and elucidated by many researchers.