Nitrogen absorption into stainless steel weld metal under welding atmosphere of high pressure —nitrogen absorption into weld metal under welding atmosphere of high pressure (part 2)—

20Cr-10Ni stainless steel was welded in N₂ and N₂-Ar atmospheres at 1~30 atm pressures. Effects of welding conditions and the nitrogen partial pressure on the nitrogen content of stainless steel weld metal were systematically studied. The results are summarized as follows: (1) In the nitrogen welding atmosphere, the nitrogen content of the weld metal decreased with increasing the welding current and increasing the travel speed, and with decreasing the arc voltage. (2) In the nitrogen welding atmosphere, the nitrogen content of the weld metal increased with the nitrogen pressure, but the nitrogen absorption of the weld metal does not obey the Sieverts' law. (3) In N₂-Ar welding atmosphere, the nitrogen content of the weld metal was lower in high atmospheric pressure than in low pressure at the same nitrogen partial pressure. (4) Using thermodynamic data obtained by equilibrium study, the nitrogen absorption into the stainless steel weld metal in the nitrogen atmosphere of high pressure was discussed. (5) All stainless steel weld metals had no porosity.