Abstract

This study investigates the influence of chromium on the fracture behavior of TWIP steels with a base composition of Fe-22Mn-0.6C, and with chromium contents of 0%Cr 5% Cr and 10% Cr. The fracture toughness of all three alloys was evaluated by the JIC parameter using the basic method described in ASTM Standard E1820. Additionally, the fracture surfaces of the steel were characterized using light microscopy, X-ray diffraction (XRD), and FEG-SEM-EBSD. A combination of intergranular and transgranular fractures was observed during stable crack growth in all steels. The fracture surface morphologies predominantly consisted of dimples and cleavage facets in the 0%Cr and 5%Cr steels, while cleavage was dominant in the 10%Cr steel. A qualitative analysis of the zone immediately ahead of the crack tip, termed the blunting zone, was also performed. The width of this zone (Stretch Zone Width, SZW) was measured and analyzed as a parameter to assess the fracture toughness of the material.