High Temperature Tensile Properties of TiN-Reinforced 17-4 PH Stainless Steel Produced by Laser Powder-Bed Fusion

Abstract In this study, the effect of TiN particle reinforcements on high temperature tensile behavior of laser powder-bed fusion processed 17-4 PH stainless steel has been investigated. Tensile tests have been conducted at room temperature (RT), 400 °C, and 600 °C. It was observed that the TiN incorporation increased the strength at RT and 400 °C with a slight tradeoff in elongation. However, at 600 °C, yield and tensile strength values were lower for the composite than those of the unreinforced steel matrix, yet with a threefold increase in elongation. Further investigation on the ruptured specimens revealed that dynamic recovery, recrystallization, and phase transformation were responsible for this behavior. It has been concluded that dispersion hardening offers advantages both at room and elevated temperatures, especially in the ranges where the original alloy is normally used. However, the physical characteristics of the matrix become dominant at high temperatures (> 0.5 T m ), setting an upper bound to the possible contribution of the reinforcement to a selected matrix, yet, enabling for higher ductility.