Current Status of Degradation Problem and Advanced Materials in Petroleum Industry Pressure Vessels

Abstract

The C-0.5Mo and Cr-Mo low alloy steels have been widely used for high temperature and high pressure hydrotreating reactor vessels in the petroleum industry. Material degradation problems during the long term services are present concerns regarding the reliability of the pressure vessels. Recently, to improve the material resistances against long term hydrogenation services, advanced type Cr-Mo steels with higher design stress and modified alloy compositions has been developed and certified in the ASME B & PV Code. In this paper, present topics of the study on material degradation problems such as creep cracking, hydrogen attack and hydrogen embrittlement will be reviewed for conventional and advanced type pressure vessel steels.