1989 Volume 7 Issue 1 Pages 49-56
Pure iron plates were welded using Fe-Mn and Fe-Si-Mn alloy electrode wires in a controlled arc atmosphere. The effects of manganese and silicon-manganese on the oxygen contents and non-metallic inclusions in the weld metals were investigated under various welding conditions in Ar-O2 and Ar-CO2 welding atmospheres. The oxygen contents of the Fe-Mn and Fe-Si-Mn weld metals increase with an increasing the partial pressure of oxidizing gases and decrease with an increasing manganese and silicon-manganese contents in the weld metals. The oxygen contents of the weld metals welded in Ar-CO2 are lower than those in Ar-O2. The oxygen contents of the Fe-Si-Mn weld metals significantly decrease comparing with those of the Fe-Si and Fe-Mn weld metals. The nonmetallic inclusions in the Fe-Mn and Fe-Si-Mn weld metals increase with an increasing oxygen contents of the weld metals. The nonmetallic inclusions in the Fe-Mn weld metals are oxide of manganese-oxide accompanying with iron-oxide. The nonmetallic inclusions in the Fe-Si-Mn weld metals are oxide composed of silica, manganese-oxide and iron-oxide. Behavior of the oxygen absorption into the Fe-Mn and Fe-Si-Mn weld metals is discussed using thermodynamic data.
