Boronizing on low carbon-high strenght steel

Low carbon-high strength steels used in many different sectors in industry can be expanded by surface treatment. As a result of their low carbon, hardener elements must be impregnated through diffusion from the surface and this process must be carried out at the lowest possible temperature and time. In cases boronizing is the best decision when high hardness and abrasion resistance is required on the surface. For this purpose, this study was carried out in order to obtain the boride layer depth to be formed on the surface with a boronizing powder mixture undergoing a pre-treatment such as mechanical alloying (MA) at the lowest possible temperatures. Samples with DIN St28 standard were boronized at 650-700-750-800-850 °C temperatures and boronized 3-6-12 hours heat treatment times with mechanical alloying powder mixture using a planetary grinder of 0, 10 and 20 hours. The samples were examined in terms of wear values over weight loss using optical and scanning electron microscopes, powder and boride layer characterization with x-rays, surface-to-center hardness distribution with vicker hardness measurement method and Pin-on-Disk method. As a result of the findings, it was not possible to obtain a boride layer at 650 ° C by using the gel obtained with the powders without mechanical alloying, while the boride layers were obtained as a result of 6 and 12 hours of boronization in 10 and 20 hour processes. The activation energies of the powders were calculated by each mechanical alloying process and found to be 113,555, 108,814 and 106,746 kJ/mol, respectively. With the increasing temperature and boronizing times, significant increases in layer thickness and hardness were observed, and consequently, significant reductions in weight loss due to abrasion were obtained. A decrease in activation energy and a significant increase in layer thickness and mechanical properties were achieved by pretreating the powders to be used in boronizing process, which is a diffusional process, such as mechanical alloying.