Study On Properties Of T92/Super304H Dissimilar Steel Welded Joints And Its Welding Process Optimization

Ultra-supercritical electric power unit is currently the most advanced clean coalpower generation technology, with its high efficiency, environmental protection,energy saving and other advantages and will be the trend of thermal power within along time. Localization in boiler manufacturing and installation process willinevitably produce T92/Super304H dissimilar steel welded joints.In welding thermal cycle and the device operation process, the difference incoefficient of thermal expansion and the formation of thermal stress and carbonmigration of dissimilar steel joints will lead adverse changes in physic, chemical, andmechanical properties, but also lead to bad high-temperature creep resistance.Therefore, the T92and dissimilar steel joints Super304H performance in-depth study,an important role. In this paper, T92/Super304H dissimilar steel joint performance,organizations, and the effects of different processes studied systematically inoptimizing the process.Different welding processes are developed including T92side groove angle,welding wire types, interpass temperature, welding layers, the heat treatmenttemperature. Microstructure and mechanical properties includeing tensile properties atroom temperature, iMPact resistance, hardness distribution of T92/Super304H steelwelded joints under different process are conducted. Research results show that theoptimal groove angle of T92side is35°and the welding wire should selecti ErNiCr-3.Six layers is more suitable than four layers and the layer temperature should becontrolled between150~200℃, at the same time the optimal heat treatmenttemperature can also be740℃or760℃.Finite element anlysis with Abaqus are choosed to welding temperature and thedistribution of residual stress under different welding processes. The weldingtemperature results simulate the actual situation of welding. The results show thatgroove angle have big iMPact on the residual stress distribution on T92/Super304Hwelded joints, while the trend of residual tensile along welded joints usingErNiCrMo-3welding wire will be greatly improved.