Prediction of Corrosion in the Stainless Steel 316L in the Near-Surface Zone by Numerical Simulation

Austenitic stainless steels such as 316L (1.4404) are widely used in chemical plant engineering applications because of their exceptional corrosion resistance. However, forming processes significantly affect the material's microstructure, which in turn influences its corrosion behavior. Depending on the chemical composition and forming history, 316L tends to martensite formation during forming, which strongly impacts the corrosion behavior in narrow zones close to the surface. In forming processes with tool contact, local martensite formation occurs at least on the surface up to a few micrometers into the bulk of the material. The residual stress state, phase fractions, crystallite sizes and microstrain are experimentally determined by x-ray diffraction and numerically predicted. This paper introduces a numerical approach to predict corrosion rates of 316L after cold rolling. The method extends conventional forming simulations with empirically calibrated models that factor in the component surface and the near-surface microstructure. This approach facilitates the optimization of workpiece designs and forming processes and is also adaptable to other materials and forming operations.