Hydrogen Cracking of Duplex Stainless Steel Weldment

The methods of measuring diffusible hydrogen, the mechanical properties and the critical hydrogen level not to crack were investigated on Ferralium 255 and Alloy 2205 duplex stainless steel weldments using Ferralium 259 and 2209/2209W SMAW electrodes. The diffusible hydrogen in the duplex stainless steel weldment was found to be exactly measurable at 673K for 259.2ks. Fisheyes characterized by circular bright spots with a pore or a slag inclusion at the center were observed on the tensile fracture surfaces of Ferralium 259 weld pad. The weld cracking hardly occurred below 7ppm hydrogen in G-Bop test of Ferralium 259 welds. The weld cracking of 2209/2209W welds hardly occurred below 34ppm hydrogen in Y-Groove test and below 25ppm hydrogen in G-Bop test.