SURFACING OF 3. 25% NICKEL STEEL WITH INCONEL 625 BY THE GAS METAL ARC WELDING-PULSED ARC PROCESS.

It was found that Inconel 625 was directly weldable onto 3. 25 nickel steel. Tensile properties were generally comparable to those for 3. 25 nickel steel, and the most favorable mechanical properties were obtained with a heat input of 1. 77 MJ/m (45 kJ/in. ). The corrosion fatigue strength of the surface weld metal 10**10**8 cycles was 10. 34 MPa (15 ksi), which is lower than values reported for multiple pass Inconel 625 welds but is significantly higher than the corrosion fatigue strength of the steel. Fatigue crack growth rates for the surface weld metal were higher than the wrought Inconel-625 base metal and the steel. The seawater corrosion resistance of the surface weld metal was equivalent to the wrought base metal at levels of iron up to 9%, provided the molybdenum concentration was greater than 8%.