文献类型：会议论文

英文题名：Pitting Corrosion and Stress Corrosion Cracking around Heat Affected Zone in Welded Joint of CrNiMoV Rotor Steel in Chloridized High Temperature Water

作者：Luo, L. H.[1];Huang, Y. H.[1];Xuan, F. Z.[1]

机构：[1]E China Univ Sci & Technol, Sch Mech Engn, MOE, Key Lab Safety Sci Pressurized Syst, 130 Meilong St, Shanghai 200237, Peoples R China

会议论文集：14th International Conference on Pressure Vessel Technology (ICPVT)

会议日期：SEP 23-26, 2015

会议地点：Chinese Pressure Vessel Inst, Shanghai, PEOPLES R CHINA

主办单位：Chinese Pressure Vessel Inst

语种：英文

外文关键词：Steam turbine rotor steel; Welded joint; Pitting corrosion; Stress corrosion cracking

摘要：Pitting corrosion and stress corrosion cracking around heat affected zone of 25Cr2Ni2MoV rotor steel welded joint in chloridized high temperature water were studied by using U-bend specimen exposure test and electrochemical test. Different corrosion potentials were detected in various zones of welded joint with the order: heat affected zone > base metal > weld metal. By contrast, a reversed order was observed for pit density in welded joint which was partly ascribed to the galvanic effect of different zones. Stress corrosion cracks initiated from pits preferentially at the fusion line was observed because of its most complicated microstructure and highest hardness. A finite element analysis was carried out to evaluate the plastic strain distribution on the U-bend specimen. A great leap of the plastic strain from the weld to the fusion line could also explain the significant susceptibility to stress corrosion cracking at the fusion line. (C) 2015 Published by Elsevier Ltd.