应力腐蚀开裂（SCC）是护环失效的主要方式，所以抗SCC能力成为护环材料的主要考核指标。随着氢冷的运用，氢致开裂（HEC）也成为考核指标之一。自七十年代以来，世界各国都致力开展新型的抗SCC用的护环材料——18－18N（Mn18Cr18N）钢，我国也自“七五”计划正式投入研究。本 Stress Corrosion Cracking (SCC) is the primary means of retaining ring failure, so the ability to resist SCC as the main assessment indicators of retaining ring material. With the use of hydrogen-cooled, hydrogen induced cracking (HEC) has also become one of the evaluation indicators. Since the 1970s, all countries in the world have devoted themselves to the development of a new type of 18-18N (Mn18Cr18N) steel material for guarding against SCC. Our country has also been formally put into study since the “Seventh Five-Year Plan”. this