Assessment of the hot cracking susceptibility of austenitic stainless Cr-Ni-steels during laser welding

摘要

A series of austenitic stainless Cr-Ni steels near the eutectic trough may solidify during laser welding both in primarily ferritic or primarily austenitic mode. Hot cracking tests of special concepts reveal a hot cracking susceptibility of the microstructures with primarily austenitic solidification during laser welding using low energy input as distinct from TIG-welding using high energy input. This is explained by the fact that, unlike a slow solidification via stable delta-states, residual melts may be formed during a rapid solidification via primary gamma-states which exhibit quite important temperature-dependent drops in toughness compared with the parent material.