Welding solidification cracking susceptibility and behavior of nickel based ERNiMo-2 wire

The welding solidification cracking susceptibility of ERNiMo-2 wire was studied by trans-varestraint test. Results show that the threshold strain and saturated strain are 4% and 8% respectively. In this range, the maximum crack length increases continuously with strain. Solidification cracks occur in interdendrites and extend along solidification grain boundaries. The strain and eutectic M6C which reducing the binding force of grain boundaries, are the main factors affecting the solidification cracking. The segregation of Si and P at the grain boundary is also beneficial to the formation of liquid film, which enlarges the solidification temperature range and further increases the welding solidification cracking susceptibility of weld metal.