The effect of TiC addition on the microstructure and properties of CX stainless steel prepared by selective laser melting

To investigate the effect of TiC addition on the microstructure and mechanical properties of CX stainless steel fabricated by selective laser melting (SLM), samples with different TiC contents (0, 2wt.%, 4wt.%, and 6wt.%) were analyzed using characterization techniques such as XRD, SEM, and EBSD. The results indicate that the addition of TiC significantly influences the grain size of CX stainless steel, thereby affecting its mechanical properties. EBSD analysis reveals that as the TiC content increases, the average grain size of CX stainless steel decreases from 2.08 μm to 0.94 μm, 0.66 μm, and 0.71 μm, respectively, with a maximum reduction of 68.3%. The hardness of CX stainless steel gradually increases with higher TiC content, reaching a maximum of 491 HV0.5, which represents a 63.1% improvement compared to the original printed CX stainless steel. The tensile strength initially increases and then decreases with increasing TiC content, peaking at 1574 MPa when the TiC content is 4wt.%, a 58.2% compared to the original printed CX stainless steel. The elongation at fracture first increases and then decreases with higher TiC content, reaching a maximum of 16.8% at 2wt.% TiC, a 29% improvement compared to the original printed CX stainless steel. When the TiC content is 4wt.%, CX stainless steel exhibits optimal comprehensive mechanical properties: yield strength of 1081 MPa, tensile strength of 1574 MPa, and hardness of 360 HV0.5, representing improvements of 21.1%, 58.2%, and 21.5%, respectively, compared to the original printed CX stainless steel.