Research of temperature phenomena during the mechanical processing of steels and iron

Abstract

Purpose. Research of temperature phenomena in the cutting zone of steel and cast iron blanks in the conditions of industrial production by methods of computer modeling of non-stationary processes of heat exchange during mechanical processing and the search for the optimal material for a cutting tool. The methods. Research methods were based on the basics of the theory of cutting and cutting tools, the theory of heat conduction in relation to the contact surfaces of the cutting tool and the workpiece in the cutting zone. Use of an application program for modeling thermal phenomena during mechanical processing of metals and alloys. Determination of optimal cutting modes taking into account temperature changes. Findings. A computer experiment confirmed that the optimal cutter materials when processing 30X steel is a tool made of P6M5 material, and it is better to use a tool made of VK8 material for processing ChCh20 cast iron. With the same cutting parameters (cutting depth, feed, cutting speed, tool geometry), the contact surfaces heat up less, and therefore the tool will lose its cutting qualities more slowly and will last longer, with the proper quality of the final product. If there is a lack of cutters made of optimal materials in the conditions of limited capabilities of the enterprise, it is possible to use a non-optimal tool material for mechanical processing of steels and cast irons with small cutting depths of up to 1 mm and at low feed - 0.2 mm/rev. At greater depths of cutting and feeding (t > 1 mm, S > 0.2 mm/rev), temperatures in the cutting zone rise rapidly, increasing by 20-40ºС, which negatively affects the processing process and reduces the stability of the cutting tool. The originality. Optimum modes of cutting and brands of materials of parts and workpieces, which will ensure high quality of processing, have been established. Research of thermal processes of the tool-workpiece system with determination of the temperature at any point on the contact surfaces. Practical implementation. Using the application program allows you to determine the temperature of the appropriate point of the cutting wedge, simulate the distribution of the thermal field for different cutting modes (cutting depth, feed, cutting speed, tool geometry) and set their optimal values, taking into account the material of the cutter and the workpiece. This will significantly speed up the preparation of the technological process of mechanical processing, ensure the required quality and minimize costs.