Comparison of Ti and Nb microalloy elements effects on the microstructure and mechanical properties of a Quenched-Partitioned Cast steel

In the present study, the effect of Ti and Nb microalloying elements on the microstructure and mechanical properties of the quench-partitioned (Q-P) steel was investigated. The samples containing Ti and Nb micro-alloying elements were subjected to Q-P heat treatment and quench-Tempering (Q-T). After Q-P and Q-T heat treatment, the properties of the samples were examined by scanning electron microscopy (SEM), X-ray analysis (XRD), microhardness, tensile tests and. The results showed that Q-P heat treatment of both sample has better mechanical properties compared to Q-T heat treatment. In the Q-P heat treatment, the amount of retained austenite (γR) for the sample containing Ti is higher than that of the sample containing Nb. Fracture strength and strain of the sample containing Ti were recorded 1070 MPa and 24%, respectively. The fracture strength and strain of the sample containing Nb were also recorded 980 MPa and 19%, respectively. In Q-P heat treatment, the plasticity of the sample containing Ti microalloy is higher than that of the Nb microalloy sample.