Influence of various heat treatment processes behavior of a novel maraging steel coating process on the microstructure, nanoindentation pattern, and wear

Abstract

Effective subsequent heat treatment is essential for achieving excellent performance in maraging steel. This paper presents the preparation of a maraging steel coating with a high content of Mo and Co elements using laser cladding technology. The study investigates the effects of direct aging treatment and solid solution-aging treatment on the microstructure, elemental distribution, crystallographic features, nanoindentation characteristics, and wear behavior of the coatings. The results indicate that all three coatings consist primarily of α-Fe with a small amount of γ-Fe, and solid solution-aging treatment effectively inhibits the martensite-to-austenite transformation. Following both heat treatments, a significant number of nanoscale precipitated phases were observed within the martensitic matrix, proving pivotal in enhancing the coatings' hardness. Notably, the solid solution-aging-treated coating exhibits excellent nanomechanical properties, with a hardness of approximately 8.39 ± 0.19 GPa, representing a remarkable 75 % improvement compared to the untreated coating. Second-phase strengthening and dislocation strengthening are identified as the primary mechanisms responsible for enhancing the solid solution-aging coating. Furthermore, solid solution-aging treatment significantly enhances the wear performance of the coatings, as evidenced by a dry sliding average friction coefficient of 0.578 and a wear volume of (3.18 ± 0.97) × 106 μm3, surpassing those of the original coatings. The observed wear mechanisms include abrasive wear, oxidative wear, and slight adhesive wear, with the precipitation of nanoscale precipitated phases playing a key role in enhancing wear resistance.