The Nitrogen Absorption of Fe-Cr and Fe-Ni Weld Metals during Gas Tungsten Arc Welding
Takeshi Kuwana, Hiroyuki Kokawa, Ken-ichiro Naitoh
pp. 169-175
DOI:
10.2207/qjjws.7.169Abstract
Fe-Cr and Fe-Ni alloy sheets were welded by gas tungsten arc welding in an arc atmosphere-controlled chamber filled with argon-nitrogen gas mixtures in order to stduy effects of chromium and nickel on the nitrogen absorption of iron alloy weld metal. In Fe-Cr alloys, the nitrogen content of weld metal decreases with increasing the welding current. In Fe-Ni alloys, the nitrogen content of weld metal hardly depends on the welding current. In each alloy, the nitrogen content of weld metal increases with the nitrogen partial pressure of the atmosphere in low nitrogen partial pressure region, and is constant in nitrogen partial pressure more than 0.01MPa. The nitrogen content of weld metal increases remarkably with the chromium content, while decreases slightly with increasing the nickel content. The nitrogen absorption of iron alloy weld metals was discussed thermodynamically by comparing with data of arc-melting and equilibrium.