Microstructure, Residual Strain and Stress Corrosion Cracking Behavior in 316L Heat-Affected Zone
来源期刊:Acta Metallurgica Sinica2016年第9期
论文作者:Hong-Liang Ming Zhi-Ming Zhang Peng-Yuan Xiu Jian-Qiu Wang En-Hou Han Wei Ke Ming-Xing Su
文章页码:848 - 858
摘 要:Austenitic stainless steels are usually chosen to make many components of nuclear power plants(NPPs).However,their microstructure in the heat-affected zone(HAZ)will change during the welding process.Some failures of the weld joints,mainly stress corrosion cracking(SCC),have been found to be located in the HAZ.In this research,the microstructure,micro-hardness,residual strain and SCC behavior at different locations of the 316L HAZ cut from a safeend dissimilar metal weld joint were studied.However,traditional optical microscope observation could not find any microstructural difference between the HAZ and the base metal,higher residual strain and micro-hardness,and higher fraction of random high-angle grain boundaries were found in the HAZ than in the base metal when studied by using electron back-scattering diffraction scanning and micro-hardness test.What’s more,the residual strain,the microhardness and the fraction of random grain boundaries decreased,while the fraction of coincidence site lattice grain boundaries increased with increasing the distance from the fusion boundary in 316L HAZ.Creviced bent beam test was applied to evaluate the SCC susceptibility at different locations of 316L HAZ and base metal.It was found that the HAZ had higher SCC susceptibility than the base metal and SCC resistance increased when increasing the distance from the fusion boundary in 316L HAZ.
Hong-Liang Ming1,2,Zhi-Ming Zhang1,Peng-Yuan Xiu1,Jian-Qiu Wang1,En-Hou Han1,Wei Ke1,Ming-Xing Su3
1. Key Laboratory of Nuclear Materials and Safety Assessment,Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research,Chinese Academy of Sciences2. University of Chinese Academy of Sciences3. Shanghai Research Center for Weld and Detection Engineering Technique of Nuclear Equipment
摘 要:Austenitic stainless steels are usually chosen to make many components of nuclear power plants(NPPs).However,their microstructure in the heat-affected zone(HAZ)will change during the welding process.Some failures of the weld joints,mainly stress corrosion cracking(SCC),have been found to be located in the HAZ.In this research,the microstructure,micro-hardness,residual strain and SCC behavior at different locations of the 316L HAZ cut from a safeend dissimilar metal weld joint were studied.However,traditional optical microscope observation could not find any microstructural difference between the HAZ and the base metal,higher residual strain and micro-hardness,and higher fraction of random high-angle grain boundaries were found in the HAZ than in the base metal when studied by using electron back-scattering diffraction scanning and micro-hardness test.What’s more,the residual strain,the microhardness and the fraction of random grain boundaries decreased,while the fraction of coincidence site lattice grain boundaries increased with increasing the distance from the fusion boundary in 316L HAZ.Creviced bent beam test was applied to evaluate the SCC susceptibility at different locations of 316L HAZ and base metal.It was found that the HAZ had higher SCC susceptibility than the base metal and SCC resistance increased when increasing the distance from the fusion boundary in 316L HAZ.
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