Mechanical behavior and interfacial damage of carbon steel-stainless steel corrosion resisted-alloy (CRA) cladded plate: Hybrid analysis based on experiment and finite element modeling

Abstract

The deformation behavior of a hot roll-bonded stainless steel/carbon steel (STS/CS) clad plate is investigated by focusing on the mechanical properties-microstructure relationship along the plate thickness and clad interface. In detail, the mechanical responses of the STS/CS clad plate and its constituents are evaluated using uniaxial tension, interfacial debonding tests (in normal and shear modes), and various microstructure characterization techniques, which clarify the interfacial heterogeneity of the STS/CS clad plate. The results of experimental analysis present the validity for applying a hybrid numerical–experimental identification procedure for the cohesive zone model (CZM) in the simulation of heterogeneous STS/CS interface using finite element (FE) method. Especially, the mixed-mode bilinear CZM coupled with the inhomogeneously distributed elastic-plastic properties over thickness can be optimized to accurately predict the measured load-displacement curves and springback in the two debonding tests and the V-bending test. Finally, the interfacial failure characteristics of the STS/CS clad are further presented through the comparison between the FE method and fractography analysis at the clad interface. The combined experimental and numerical study reveal interesting aspects beyond commonly reported interfacial behavior. These include: (1) The failure along the STS/CS clad interface is controlled by both “material factors” such as the carbon migration from the interface and its resultant differential strengthening through the thickness, and “process factors” that includes the gradient of strength and temperature across the clad and rolling tools. (2) The major deformation mode is variable according to locations and the mixed normal-shear mode is dominant at tool contacts for initiating the failure during the V-bending test. (3) The interfacial failure mechanism of cladding featured not only in a confined deformation zone where contact directly with tools, but also the exterior area where springback after unloading caused a drastic change of stress state. These abrupt interfacial failures could be clarified via stress state and local damage analysis of the well-reproduced FE model of cladding material.