On CO₂-O₂ Arc Weldling of Low Alloy Steels for Low Temperature Service (Report 2)

Impact value of weld metal

Abstract

The effect of several elements on impact value of low nickel alloy steel weld metals was investigated by a bead-on-plate experiment, with deposit by the CO₂-O₂ arc welding using several electrode wires of various compositions. The following results were obtained:
(1) If a low nickel alloy steel is welded by high current automatic welding with an electrode wire of which composition is the same as base metal, it is difficult to get an as-welded metal, of which the impact value is equal to that of base metal.
(2) Though it is generally said that nickel has a highly beneficial effect on the low temperature notch toughness of steel, nickel of as-welded metals of low nickel alloy steels did not improve its impact value so effectively as that of heat-treated base metal.
(3) In as-welded metal molybdenum was more effective than nickel to improve the impact value.