Thermodynamic Analysis Of Bond Breakage And Entropy Production Model For Carbide Tool

2.25Cr1Mo0.25V steel is an important metal material for the production ofhydrogenation reactor core equipment cylinder used in petroleum chemical industryin China. Although the2.25Cr1Mo0.25V steel has the advantages of high strength,good plasticity, high temperature resistant etc, at the same time it is also a veryintractable material, which results in the phenomenon of breakage frequently,limiting the improvement of production efficiency and the control production costseriously. Relying on the National Natural Science Foundation of China "Study onthe sticking failure mechanism of tool when cutting the tube section materials withhigh efficiency and heavy duty"(Project No.51075109), according to the adhesionwear and seriously damaged for carbide tool in the process of cutting2.25CrlMo0.25V steel, using the method of thermodynamics to analyze thephenomenon of bond breakage.First of all, the cutting experiment platform for2.25Cr1Mo0.25V steel is builted,a comparative experiment for carbide bond breakage is conducted, the carbide tool isselected whose rake surface damage more seriously; The contact state of tool andchip is analyzed, the calculation formula of the contact area for tool and chip isestablish; According to the experiment data of cutting force, the empirical formulafor the main cutting force and verify its effectiveness is established.Secondly, according to the conduction model of cutting heat, the heat flux forincoming is calculated. The influence rule of cutting tool materials and cuttingparameters on cutting temperature is analyzed. By the finite element simulationsoftware called Thirdwave, simulation analysis for the tool temperature field iscarried out, and the distribution of temperature for rake face is gotten, it is found thatabout0.5mm from the cutting edge the cutting temperature reaches the maximumvalue, providing the basis for the study on the effect on the bond breakage of cutting temperature.Finally, the forming conditions and process of bond breakage for carbide toolbriefly is analyzed, and the effect of cutting temperature and micro cracks on thebond breakage is analyzed; According to establish thermodynamic function, the bondbreakage thermodynamically is analyzed. The relation between the depth bonddamage and the Gibbs free energy is established. According to the principle ofgenerating minimum entropy, the entropy production model for plastic deformationzone and tool chip contact area is set up, and the model briefly is analyzed.