Determination of LME sensitivity of zinc-coated steels based on the programmable deformation cracking test

Abstract

AbstractThe current work presents a new test method to evaluate liquid metal embrittlement (LME) susceptibility of zinc-coated steels in arc processes under application-oriented conditions. The procedure is based on the programmable deformation cracking test (PVR test). The PVR test is a variation of a controlled tensile test for hot cracking investigations in arc welding processes. Two dual-phase steels (DP600, DP980) and five transformation-induced plasticity steels (TRIP690, TRIP700, TRIP700, TRIP1100, TRIP1200) were used. The investigations showed that comparable thermo-mechanical loading conditions can be guaranteed for materials of different sheet thicknesses in the PVR test through a targeted adjustment of the heat input per unit length of weld. Furthermore, it was shown that the critical deformation rate $${v}_{cr}$$ v cr (used for assessing hot cracking susceptibility) may also be used to assess the LME susceptibility of a particular steel. Furthermore, another LME susceptibility parameter, the relative reduction in load-bearing ability $$\Delta\Sigma$$ Δ Σ could be derived, which may be used to understand how LME cracking affects materials’ mechanical and fracture properties.