Quantification of hydrogen effective diffusion coefficients and effusion behavior in duplex stainless steel weld metals

Effect of Gas Tungsten Arc Welding Parameters on Hydrogen-Assisted Cracking of Type 321 Stainless Steel

“…[45] It was shown [30] that the amounts of hydrogen stored in weld metal and base metal are different. Charging of the base metal introduces a greater amount of hydrogen during the same time as charging of the weld metal.…”

“…[18] It is known that hydrogen induces a martensitic transformation in austenitic steel and causes an embrittlement of austenitic stainless steels, including welding structures. [19][20][21][22][23][24][25][26][27][28][29][30][31][32] However, hydrogen effect on welded microstructures and hydrogen embrittlement is not fully understood. It is known that welds in austenitic steels contain several percent of d-ferrite-a phase that helps prevent hot cracking but provides a preferred path for crack propagation in the presence of hydrogen.…”

“…The effective hydrogen diffusion coefficient in the base material is higher than that of the weld metal due to the tortuous path of hydrogen diffusion in the weld area. [30] Padhy et al [31] investigated hydrogen distribution and cracking susceptibility of a martensitic-austenitic steel weld by measuring hydrogen desorption in ambient atmosphere and under cathodic charging. In ambient atmosphere, the weld is not susceptible to HAS, because the most part of hydrogen is trapped in the austenite phase.…”

Corrosion behavior of hydrogen charged super duplex stainless steel welded joints

“…However, it is strongly related to steel microstructure which can be affected by different manufacturing processes, especially welding. The susceptibility of ferrite (α) and austenite (γ) phases to hydrogen are not alike be due to different behavior of hydrogen in each phase, such as solubility and diffusivity of hydrogen . Therefore, two‐phase anisotropic microstructure cause that the movement of hydrogen in the duplex steels is a function of crystallographic orientation and the presence of boundaries, defects, etc.…”

“…Dabah et al compared the behavior of hydrogen in DSS during hydrogen charging and during welding. The total concentration of hydrogen apparently differed in the analyzed conditions of hydrogen entry.…”