The safe-end weld of reactor pressure vessel nozzle is dissimilar metal weld

which connects low alloy steel and stainless steel with Inconel 690. The welding material Inconel 690 is easy to generate micro-cracks

lack of fusion

oxide inclusions and other defects in the manufacturing process. By analyzing defect generation mechanism and combining actual manufacturing situation

the effects of chemical composition

welding method

welding parameters

auxiliary procedure measures and groove structure on the defect sensitivity of welding material Inconel 690 are studied. The results show that reasonable control of alloy element content can reduce the sensitivity of crystal crack. Appropriate reduction of welding heat input and avoidance of molten pool overheating can reduce the sensitivity of crack and lack of fusion. Control of groove shrinkage deformation can avoid adverse effects on welding quality.