Engineering guide line of high strength pressure vessel Cr-Mo steels for high temperature service

Abstract

Upgrading of heavy crude oil and coal liquifaction requires large size pressure vessels for higher pressure and temperature operation in hydrogen service than conventional hydrotreating process. In order to meet such industrial needs, study on advanced Cr-Mo steel which has higher design stress, excellent resistance to hot hydrogen damages has been studied in recent 10 years in worldwide development programs such as API/ MPC in USA, NEDO in Japan. ASTM/ASME, JIS and Europian standard materials are available in many kinds of advanced Cr-Mo steel such as Enh. 21/4 Cr-1Mo, Mod. 3cr-1Mo. Mod. 21/4Cr-IMo, Manufacturing of large size pressure vessel weighs over 1, 000m-tons using new grade steel have been commenced and application of new grade steel in large size pressure vessel increases in recent years.
The ECM committee in Iron and Steel Division in the Japan Welding Engineering Society established the enginering guide line of Advanced Cr-Mo Steels in 1992 after two years extensive study which includes proposed material standards, data base of mechanical properties, design stress values, phisical properties, recommendable welding practice and data of enviromental properties. This report interprets the engineering guide line and recent trend in application of advanced Cr-Mo steel in pressure vessel industries.