Characterization of the elasto-plastic properties of 0Cr12Mn5Ni4Mo3Al steel by microindentation

This paper investigated the micro mechanical behavior of 0Cr12Mn5Ni4Mo3Al high strength stainless steel with different heat treatment conditions (RH520 and TH560) and different texture directions (longitudinal direction-L and cross direction-T) by microindentation. A non-destructive approach was proposed to extract mechanical properties (Young’s modulus E, micro-hardness H, yield stress σy and strain hardening exponent n) of the material from its given experimental indentation P-h curves. It was found that the loading speed had little influence on measurement of Young’s modulus and micro-hardness. Young’s modulus E and micro-hardness H decreased with the increase of indentation load, which showed strong indentation size effects. The plastic properties were described through dimensional analysis, and revealed that the heat treatment conditions and texture directions of 0Cr12Mn5Ni4Mo3Al steel had little effect on strain hardening exponent n, but had significant influence on yield stress σy. The computational results were compared well with experimental dates, which showed the prediction of mechanical properties by microindentation is accurate.