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利用激光双面焊接10 mm厚奥氏体不锈钢,焊接参数P=3.5 kW、v=20 mm·s~(-1)、离焦量为-1 mm时,得到最优焊缝。对拉伸试样进行电化学充氢,然后进行拉伸试验,观察断口位置及形态。结果表明:在0.5 mA的电流下充氢96h后,奥氏体不锈钢焊缝的强度、塑性和韧性均有一定程度的降低,拉伸试样是在焊缝处发生断裂,说明焊缝相比于母材对氢的敏感性更高;充氢后拉伸试样断口表层由充氢前的韧性断裂转变为由氢导致的脆性断裂。
The optimal welding seam was obtained by laser welding of 10 mm thick austenitic stainless steel with welding parameters of P = 3.5 kW, v = 20 mm · s -1 and defocus amount of -1 mm. Tensile specimens were electrochemically charged with hydrogen and then subjected to a tensile test to observe the fracture location and morphology. The results show that the strength, ductility and toughness of the austenitic stainless steel weld are all reduced to some extent after being filled with hydrogen at a current of 0.5 mA for 96 hours. The tensile specimen is fractured at the weld, indicating that the weld The sensitivity to hydrogen is higher in the base metal; the fracture surface of the tensile specimen after hydrogen charging changes from ductile fracture before hydrogen charging to brittle fracture caused by hydrogen.