Effect of TiC Precipitaiton on Mechanical Behaviour of Fe-28Mn-6Si-5Cr Alloy

Mechanical properties of solid solution treated Fe-28Mn-6Si-5Cr alloy were investigated by comparison with those of aged Fe-28Mn-6Si-5Cr alloy using a microcomputer control electron universal testing machine and a durometer. Based on SEM observations of the tensile fracture morphologies and TEM analysis of the deformed microstructure as well as measurements of the characterized elasticity under different tensile deformation amount and indentation load for the tested alloys, the influence of TiC precipitation on strength, hardness, elongation, contraction of cross-section area, elastic property and deformation hardening index has been discussed. The results show that Fe-28Mn-6Si-5Cr alloy possesses pseudoelasticity and double-n behavior of deformation hardening. The plastic deformation of the tested alloy is mainly in the mode of twin deformation. Dislocation slip of the aged alloy is inhibited because of TiC precipitation. The strength and elongation of the alloy as well as its contraction of cross-section area are greatly decreased and its hardness is increased slightly owing to TiC precipitation. The deformation hardening index n(1) and n(2) are decreased obviously of the alloy and its elastic property is improved due to TiC precipitation. The tensile fracture quasi-cleavage failure mechanism of the solid alloy is changed into pore gathering failure mechanism of the aged alloy because of TiC precipitation.