Characterization of stress-strain behavior of a cast TRIP steel under different biaxial planar load ratios

摘要

This paper investigates the stress-strain curves of different load paths and the initial yield surface of a metastable austenitic stainless cast steel under biaxial planar loading using cruciform specimens. These tests were carried out on a 250 kN biaxial servohydraulic tension-compression testing machine. The laborious stress determination was undertaken with a new testing method by using global elastic unloading to measure the local stiffness. Isotropic yielding and mainly isotropic strain hardening were found. To evaluate the micro-structure, the martensite formation was detected by use of a ferrite sensor and scanning electron microscopy and electron backscatter diffraction were applied.