| High-strength Steel, such as the 2.25Cr1Mo0.25V and 3Cr1Mo0.25V, is widely used in the field of coal chemical containers and equipments as its high-temperature toughness and high hot strength excellent characteristics. During the cutting process, due to the properties of the materials, cutting tools can easily produce the sticking failure in high cutting temperature, which influences the cutting efficiency. It has become a technical bottleneck, restricting the ability of enterprises processing, production efficiency and quality. This paper is standed by the national natural fund project " Research on Sticking Failure Mechanism of Tool in Efficiently Heavy Cutting Cylindrical Shell Material" (51075109). For the sticking failure of the carbide tools in the turning processes of high-strength steel materials, the constitutive model of the work-piece material, the diffusion curves of siderophile element, the identifying and forecasting the stick welding forming, will be studied in order to reveal the generation and propagation of cracks and the sticking failure mechanism of the carbide tools. These researches have important theoretical value and practical significance for rich and complete the theory of heavy-duty cutting tool design, the development of efficient heavy-duty cutting technology, enhancing the China’s major equipment production capacity.Based on the classical orthogonal cutting model and the cutting experiment of high-strength steel, cutting force empirical formula and tool-chip contact area formula are built to get force density function on the rake face. According to cutting experiment of 1Cr18Ni9Ti, the influence of cutting parameters on the cutting force is studied, the effect of workpiece materials on cutting force is analyzed.This paper uses the heat and temperature computational formula, combining with the heat generated by the first deformation zone of the temperature rise of the chip, the flux density into the tool of the heat generated by friction of the second deformation zone premenstrual flank was obtained. On this basis, the tool surface temperature distribution law was accessed by the heat density function. According to cutting experiments, the impact of cutting parameters on cutting temperature law is analyzed and thermodynamic conditions of stick welding occurs of carbide tool cutting high-strength steel is proposed, finally the impact of the cutting temperature factors is analyzed.On the basis of one-dimensional wave conduction theory, the constitutive equations of the high strength steel materials were constructed by the hopkinson bar experiment under high temperature and high strain rheological behavior, on a footing of which the research methods of simulation analysis of cylindrical shell material and the impacting law were established and studied, which of cutting parameters on the cutting forces and temperatures in the process of cylindrical shell; Correspondingly building the stress field and temperature field.Analog cutting process occurs in different conditions around the bonded breakage, the element diffusion tests between carbide tool and stainless steel 1Cr18Ni9Ti are carried out to study the element diffusion characteristics and then the concentration curves of diffusion elements are created in the time and space dimensions. Through the broken experiments, the SEM, the high-speed photography, and the X-ray analysis, the tool sticky welding process is studied in the tube section material cutting process and the identification tool sticky welding standards and the stick welding layer thickness forecast model are established. Based on the study of sticking failure process and influencing factors, the impact factors of sticking failure depth is defined. The study provides a theoretical basis to control sticking breakage of the tools, improving the cutting tools’ life and achieving the efficiently cutting. |
PDF Full Text Request