The study of nitrogen in argon gas on the angular distortion of austenitic stainless steel weldments

The objective of this study was to investigate the effect of nitrogen added in argon shielding gas on the angular distortion of austenitic stainless steels. An autogenous gas tungsten arc welding was conducted on austenitic stainless steels 304 and 310 to produce a bead-on-plate weld. The delta-ferrite content of welds was measured by using Ferritscope. The angular distortion of weldments was determined by using the mean vertical displacement method (MVDM). The present results indicate that the retained ferrite content in Type 304 stainless steel weld metals was rapidly reduced as the nitrogen addition in argon shielding gas was increased. The welding angular distortion was raised with the increase of the amount of nitrogen added in the shielding gas. This experimental result also found that the existence of retained ferrite microstructure within the austenitic matrix has a beneficial effect in reducing welding distortion tendency of austenitic stainless steel weldment.