• XRD and TEM analysis of microstructure in the welding zone of 9Cr–1Mo–V–Nb heat-resisting steel

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      https://www.ias.ac.in/article/fulltext/boms/025/03/0213-0217

    • Keywords

       

      Heat-resisting steel; welding; fine structure.

    • Abstract

       

      Under the condition of tungsten inert gas shielded welding (TIG) + shielded metal arc welding (SMAW) technology, the microstructure in the welding zone of 9Cr–1Mo–V–Nb (P91) heat-resisting steel is studied by means of X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The test results indicate that when the weld heat input (𝐸) of TIG is 8.5 ∼ 11.7 kJ/cm and the weld heat input of SMAW is 13.3 ∼ 21.0 kJ/cm, the microstructure in the weld metal is composed of austenite and a little amount of 𝛿 ferrite. The substructure of austenite is crypto–crystal martensite, which included angle. There are some spot precipitates in the martensite base. TEM analysis indicates that the fine structure in the heat-affected zone is lath martensite. There are some carbides (lattice constant, 1.064 nm) at the boundary of grain as well as inside the grain, most of which are Cr23C6 and a little amount of (Fe, Me)23C6.

    • Author Affiliations

       

      Li Yajiang1 Wang Juan1 Zhou Bing1 Feng Tao1

      1. Key Lab of Liquid Structure and Heredity of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan 250061, People’s Republic of China
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