Effects of delta ferrite on hydrogen embrittlement of austenitic stainlesssteel welds

The effects on the hydrogen embrittlement (HE) due to variation of the delt a ferrite contents were investigated on austenitic stainless steel welds. T he hydrogen distribution in the microstructure was studied by means of the hydrogen microprint technique. The damage caused by the hydrogen was evalua ted through bending and tensile tests. The ferrite-austenite interfaces act as hydrogen traps. Ferrite increases the susceptibility to hydrogen, the g reater the quantity of ferrite, the more HE, which basically modifies the f orm in which the hydrogen damages the material: it causes the austenite to change from a normal fragile fracture to a ductile fracture, accompanying t he ferrite fragile fracture. (C) 1998 Elsevier Science Ltd. All rights rese rved.