Effect of strain rate on solidification crack susceptibility of different metals

In this paper,a slow bending speed varestraint test method with con-tinuously adjustable deformation rate for testing hot cracking sensitivity is de-veloped and its working principle is described.From great amounts of tests,itis known that strain rate affects the sensitivity of solidification crack because ofits influnce on material ductility in BTR directly.The smaller the strain rate,the better the ductility and the lower the solidification crack sensitivity.The ex-tent of this effect varies with different materials,for LF-6 aluminum alloy,it isgreat,but for 16Mn,19Mn5 and 20G steels,it is small.Through systematicinvestigation,it is concluded that strain rate of a metal during welding can belowered and the resistance to solidification crack can be enhanced by reducingstructrual restraint and by adjustment of welding parameters.