EFFECT OF VANADIUM ADDITION ON DISBONDING OF 2.25CR-1MO STEEL OVERLAYWELDED WITH AUSTENITIC STAINLESS-STEEL

The effect of vanadium addition on disbonding of 2.25Cr-1Mo steel over lay welded with austenitic stainless steel has been studied with the a im of decreasing the susceptibility to disbonding at the interface of the base and weld metals. Vanadium added 2.25Cr-1Mo steel overlay weld ed did not produce disbonding cracks at all, while vanadium free 2.25C r-1Mo steel overlay welded lead to large disbonding cracks. This is at tributed to the fact that low carbon martensite was formed on the weld metal side of the interface instead of high carbon martensite which i ncreased the susceptibility to disbonding. This is due to the fact tha t vanadium carbide precipitation reduced carbon diffusion from the bas e metal to the weld metal.