Thermal fatigue life and improvement mechanism of Fe-based coatings on H13 extrusion die by laser additive remanufacturing

Abstract H13 extrusion dies are often damaged by wear, erosion and thermal fatigue, and laser additive remanufacturing is an effective method to repair damaged locations to extend their service lives of H13 steel dies. In this study, Fe-based coatings are fabricated on the surface of H13 extrusion punches by laser cladding using the Fe-based powder mixed with M2 powder of different contents, and the effects of the M2 powder on the phase compositions, tensile properties, wear performance and thermal fatigue life are systematically investigated. Results indicate that the refined structures and various types of carbides are contained in all Fe-based coatings after adding M2 powder. Compared with other three coatings, the Fe-based coating mixed with 15 wt% M2 powder exhibits better thermal fatigue life. As a consequence, an influence mechanism of M2 powder on microstructural evolution and mechanical property is also presented in detail.