INVESTIGATION OF THE INFLUENCE OF THE PARAMETERS OF THE DEPOSITION MODE ON THE HARDNESS OF 12CR18NI10TI STEEL AFTER DIRECT LASER CULTIVATION

Using the direct laser cultivation method at the ILIST-L installation, samples of stainless steel grade 12X18H10T were obtained at a laser radiation power of 1100 ‒ 1500 W with a wall thickness of 10 mm for the case of horizontal and vertical directions of growing samples relative to the larger side. The hardness and microhardness of the samples were studied, and their dependences on the growing regime were revealed. It has been established that the most rational mode, in which uniformity and a high level of properties are achieved, is the mode with a power of 1400 watts. The vertical growing direction, which causes more intense cooling of the samples, allows for an average of 5 to 15 % higher microhardness than the horizontal growing direction. An increase in power from 1100 to 1400 W reduces this difference to zero, but a further increase in power to 1500 W increases the differences by up to 15 % due to a decrease in the microhardness of horizontally grown samples. Regardless of the direction of cultivation, in the entire range of power values (from 1100 to 1500 W), the hardness of 12X18H10T grade steel in the near‒surface areas has values reduced by 15 ‒ 17 % compared to the central region of the samples. The study of the effect of the parameters of the layer deposition mode on the hardness and microhardness of manufactured products made of 12X18H10T grade steel by direct laser cultivation provides the basis for choosing the laser power and understanding its effect on the mechanical properties of stainless steel in different growing directions.