Hydrogen in HY-130 Metal.

Abstract : This report summarizes the first years investigation directed at improving the mechanical properties of HY-140 weld metal by controlling hydrogen contamination. The addition of 0.2 percent hydride formers (Misch Metal) to weld metal has been shown to eliminate diffusible hydrogen at room temperature when the argon arc shielding gas was contaminated to a 5 percent level. The hydrides formed were stable on heating to a temperature of 760 C. Misch Metal at the 0.1 percent level in the filler wire was transferred to the weld metal with an efficiency of about 20 percent and no change in metal transfer characteristics was noted. Wire with greater than 0.1 percent Misch Metal proved difficult to fabricate with the techniques investigated. (Author)