COMPARATIVE HOT CRACKING EVALUATION OF WELDED JOINTS OF ALLOY 690 USING FILLER METALS INCONEL® 52 AND 52 MSS

The purpose of the study was to conduct comparative evaluation and investigation of the sensitivity to hot cracking of the welds and welded joints during welding of Ni-base Alloy 690 using wires Inconel (R) 52 and Inconel (R) 52 MSS. Special specimens were developed to simulate conditions of deformation of the deposited metal of multi-pass welded joints in real structures. Investigation procedures using the Varestraint-Test and PVR-Test were adjusted. Comparative evaluation of the sensitivity to hot cracking of the welds made with wire Inconel (R) 52 MSS, as well as with wire Inconel (R) 52, tested by the PVR-Test procedure, showed that the Inconel (R) 52 MSS welds were more than 25 times more resistant to DDC, but several times more sensitive to solidification cracking (BTR range). Evaluation of ductile characteristics of metal of the welds made with wires Inconel (R) 52 MSS and Inconel (R) 52 showed that the Inconel (R) 52 MSS metal had no ductility dip, whereas the Inconel (R) 52 metal exhibited an obvious decrease in elongation values. The data obtained confirm that the Inconel (R) 52 MSS welds have high resistance to ductility dip cracking in the DDC range and sensitivity to solidification cracking in the BTR range.