Effect of Gas Tungsten Arc Welding Condition on Hydrogen Absorption in a Duplex Stainless Steel

Abstract:

The use of duplex stainless steels (DSSs) is steadily increasing. For many uses where joining is needed, gas tungsten arc welding (GTAW) is one of the most important joining methods for DSSs. Since hydrogen embrittlement (HE) occasionally occurs in DSSs, understanding the relationship between the extent of HE and the welding condition is crucial to prevent HE. In this research, the effect of the heat input of GTAW process on the microstructure and the extent of HE in a UNS S31260 (JIS SUS329J4L) has been investigated. For this purpose, three samples have been prepared with diffrent velosity. All the samples have been cathodically hydrogen-charged, and then subjected to tensile test at a strain rate followed by fractography observation. Thermal desorption spectroscopy (TDS) has been carried out on the samples welded at low and average velosities. The results showed that tensile properties of the welded specimens were lower than those of base metal due to coarsening of the matrix ferrite grains and loss in the fraction balance of ferrite and austenite phases in the weld metal zone, where fracture took place.

• Periodical: Materials Science Forum (Volume 941)
• Pages: 536-541
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.941.536
• Online since: December 2018
• Authors: Bahram Mirzaei*, Goroh Itoh, Alireza Khodabandeh
• Keywords: Cathodic Charging, Duplex Stainless Steel, Fractography, Hydrogen Absorption, Hydrogen Embrittlement, Thermal Desorption Spectroscopy (TDS)

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