Surface Enhancement of AISI 1045 Steels through Plasma Torch Assisted Advanced Manufacturing Nitriding Technology Utilizing AISI M50 High‐Speed Bearing Steel Powders

This article adopts the method of plasma torch additive manufacturing nitrided technology using AISI M50 high‐speed bearing steel powders to significantly improve the mechanical properties and corrosion resistance of the surface of AISI 1045 steel. By adjusting the plasma torch current parameters to 120, 140, and 160 A, the nitrogen content in the additive manufacturing nitrided layer is 0.267%, 0.375%, and 0.293%, respectively. The hardness and the tensile strength of the as‐received AISI 1045 steels are 272 HV 0.2 and 701 MPa, respectively. The hardness and tensile strength of the strengthened layer are increased to a maximum of 850 HV 0.2 and 1336 MPa, respectively. The average wear coefficient of the AISI 1045 steels is 0.85, while the wear coefficient of the strengthened layer is reduced to a minimum of 0.55, significantly improving its wear resistance. During the tensile process, the martensitic structure and nitrogen‐containing precipitates jointly produce a strong hindrance to dislocations, resulting in a significant increase in the tensile strength of the strengthened layer. Additionally, the corrosion potential and corrosion current density of the AISI 1045 steels are −0.6516 V and 8.8 × 10 − 6 (A cm −2 ). The corrosion potential and corrosion current density of the strengthened layer are improved to −0.2672 V and 2.2 × 10 − 6 (A cm −2 ), respectively.