Investigation of Hardness on the Surface Formed During the Cutting of HARDOX-500 Steel Based on the Planning of the Mathematical Model of Multi-Factor Experiments

Abstract. The article investigates the variation of hardness on the cut surface of HARDOX-500 chromium-nickel steel, depending on the physical-mechanical properties of the processed metal, particularly its hardness. For this purpose, the hardness formed during the cutting of HARDOX-500 steel has been examined using the mathematical modeling of multi-factor experiments. As a result, a full-factorial mathematical regression equation has been derived based on the dependence on waterjet pressure (P), abrasive particle consumption (Q) and longitudinal feed of the nozzle ( ). The conducted studies revealed that the hardness values on the surface of the cut area can vary significantly during hydro-abrasive cutting of the selected steel workpieces. Specifically, an increase in the longitudinal feed rate of the nozzle, the consumption of abrasive particles, and the pressure of the waterjet leads to an increase in the hardness of the cut surface. Among these factors, the longitudinal feed of the nozzle has the most significant impact on surface hardness. Furthermore, the product of waterjet pressure and longitudinal feed ( ), as well as the combined effect of all three input parameters ( , are influential factors contributing to the increase in hardness. Thus, the study of hardness in hydroabrasive cutting using multi-factor planning is one of the pressing issues in mechanical engineering.