Study on Microstructure and Properties of TIPTIG Welded Joint of G115 Steel
The microstructure and properties of welded joint of a new tempered martensitic heat-resistant steel G115 thick wall pipe were studied based on the automatic+pulsed wire feeding full argon arc(TIPTIG)welding method.The results show that the microstructure of the welded joint is tempered martensite after post-welding heat treatment,and the weld grains show two different morphologies:equiaxed crystal and columnar crystal.The coarse crystal and fine crystal in the heat affected zone are equiaxed crystal morphologies,and their grain size is much smaller than that of the base metal equiaxed crystal.No liquefaction crack is found in the heat affected zone.The tensile strength of the welded joint meets the standard technical requirements,and the average impact absorption energy of the weld at room temperature reaches 60J,which is higher than that of the current SMAW weld,effectively solving the problem of insufficient toughness of G115 steel weld.
万方数据
维普
