Evaluation of interface adhesion of hot-dipped zinc coating on TRIP steel with tensile testing and finite element calculation

In this work, a methodology for the determination of the interface adhesion strength of zinc coating on TRIP steel is present. This method consists of a conventional tensile test in combination with finite element calculation. The relation between the average interface crack length and the applied tensile stress is determined on the partially delaminated coating with in-situ tensile test. The delamination process of zinc coating on steel substrate is simulated by using a two-grain finite element model with different interface adhesion strengths. By comparing the experimental observation with the finite element calculations, the interface adhesion strength is estimated. The interface adhesion strength of the zinc coating on transformation induced plasticity (TRIP) steel is found as high as 160 MPa. The influences of microstructural parameters of zinc coating including zinc grain orientation and grain size on the delamination behavior of the zinc coating are also analyzed with the finite element model.