Investigation of C276 alloy and 316L SS TIG welded joints with ERNiCrMo-4 and ER304 welding wires

摘要

To evaluate themetallurgical properties of ERNiCrMo-4 and ER304 welding wires in the Hastelloy C276 and 316 L stainless steel lap-welded joints,the analyses of microstructure,hardness,element distribution and mechanical properties were conducted.The results indicate that the Fe-rich zone was found at joint which added ER304 wire.The weld metals(WM)in two types of joints both consist of dendritic crystal and center equiaxed crystal.Besides,a large number of inter-dendrite precipitates were confirmed as p phase andμphase.A transition zone was found at the interface between WM and 316 L base metal as a result of dilution.The WM near the interface has the highest hardness due to the fine crystals here.In the joint added with ERNiCrMo-4,a large quantity of carbides causes a stress concentration and becomes the source of cracks,resulting in a reduction in shear strength.The fracture mode in all shear samples is ductile fracture.