Lath Martensite Microstructure Modeling: A High-Resolution Crystal Plasticity Simulation Study

Lath martensite is a complex hierarchical compound structure that forms during rapid cooling of carbon steels from the austenitic phase. At smallest, i.e., ‘single crystal’ scale, individual, elongated domains, form elemental microstructural building blocks: name-giving laths. Several laths nearly identical crystallographic orientation are grouped together to blocks, in which–depending on exact material characteristics–clearly distinguishable subblocks might be observed. blocks with same habit plane packet which typically three four finally make up former parent grain. Here, fully parametrized approach presented converts an polycrystal representation into martensitic microstructures incorporating all these details. Two-dimensional (2D) and three-dimensional (3D) Representative Volume Elements (RVEs) generated based prior austenite microstructure reconstructed 2D experimental microstructure. The RVEs used for high-resolution crystal plasticity simulations fast spectral method-based solver phenomenological constitutive description. comparison results obtained reveals high quantitative agreement. stress strain distributions their characteristics change significantly if 3D used. Further conducted systematically investigate influence parameters, such as lath aspect ratio, volume, subblock thickness, scatter, grain shape global local mechanical behavior. These features happen behavior, whereas average stress–strain response not altered. Correlations between plastic behavior established.