Investigation of tribological behavior of 31CrMo12 prealloyed P/M steels by determining boro-Sintering process parameters.

In this study, samples were produced using pre-alloyed 31CrMo12 steel powders and the powder metallurgy (P/M) production method. During the sample production phase, the pressing temperature and pressure values of the powders were determined. In the sintering phase, the pressed powders were subjected to a simultaneous sintering and boronizing process, known as Boro-Sintering, where both processes were carried out in a single step. This process was performed in a solid boronizing box with Ekabor2, Al2O3, and SiC powders. The tribological behaviors of the samples obtained via the Boro-Sintering process were examined. The pre-alloyed 31CrMo12 steel powders used in the study were produced by the atomization method, with an average particle size range of 20-30 µm. The powders were pressed in two stages: cold pressing at 200 MPa and warm pressing at 300 MPa at 600°C, before moving on to the Boro-Sintering phase. The Boro-Sintering process was carried out at 950°C and 1050°C for durations of 2, 4, and 6 hours. After the Boro-Sintering process, the densities of the samples were calculated, wear data were compiled, and microhardness measurements were conducted to examine the effects of the Boro-Sintering process. Based on the obtained data, the differences and values between the samples were interpreted. The characterization of the samples after Boro-Sintering was conducted through FESEM, EDS, OM, and XRD analyses. As a result of the Boro-Sintering process, the formation of a homogeneous boride layer on the surface was achieved. An increase in the hardness of the samples was observed following the Boro-Sintering process. Optimization of the Boro-Sintering temperature and duration resulted in improvements in the tribological behaviors of the samples.