RECENT TRENDS IN THE ALLOY DEVELOPMENT OF STAINLESS-STEEL.

During the past 15 years wrought stainless steels have undergone significant changes due to various factors, including improved steelmaking techniques and an increased demand for materials to withstand increasingly severe conditions in the chemical and energy production industries. This review examines the resulting new grades of ferritic, austenitic and duplex stainless steels and their structure-property relationships. Important developments considered include: the ability to raise the alloy content in a new low-interstitial ferritic steels, without a major loss in mechanical properties; control of sulfur and molybdenum contents to provide improved corrosion resistant, free-machining ferritic stainless steels; ferritic and austenitic alloys utilizing aluminum or silicon additions to obtain resistance to high-temperature environments; high-nitrogen austenitic stainless steels with higher strength; high Cr-Mo grades for extremely severe application, and modified duplex steels containing nitrogen.