Effect of diffusion annealing on wear and cohesion behaviours of boronized AISI 1040 steel

AISI 1040 grade steel is a commonly used steel in industry. In this study, pack boriding of AISI 1040 steel was carried out in Ekabor-II powder at different temperatures (900 °C and 950 °C) for 4 h holding time, which was followed by Diffusion annealing process (DAP) for 4 h at different temperatures (950 °C and 1000 °C). The morphology of the boride layers generated on the steel surfaces was investigated using optical and SEM microscopes following boriding experiments. The micro-hardness tester was used to assess the hardness values, and the XRD method was used to determine the phases generated on the layer. In XRD analysis, a boride layer consisting of the Fe2B phase was shown to form as a single-phase structure following the DAP at 1000 ℃ for 4 h. While the original hardness of AISI 1040 steel was 233 HV0.05, the hardness increased up to 1950 HV0.05 using the Boriding process and DAP. Wear tests were carried out using the ball-on-disc method at a sliding speed of 0.3 m/s, under a load of 10 N, at a sliding distance of 500 m in a dry environment. The Daimler-Benz Rockwell-C indentation test was used to study the adhesion capabilities of the boride layer. Wear resistance increased with boriding process and diffusion annealing temperatures. It was discovered that high Diffusion annealing temperatures resulted in the best adhesion and wear resistance. [Display omitted] •A single-phase Fe2B phase was obtained in DAP carried out at 1000 °C.•A more ductile Fe2B phase was obtained with DAP.•The DAP increases the wear resistance of AISI 1040 steel by around seven times.•The service life boronized 1040 steel can be increased using the DAP against wear.