Research Of Process Parameters For Machining Cr12moV With WEDM

With the increasingly high demand for industrial products of the people in aspect of precision and quality, the manufacturing precision and quality of related mold and the mold material hardness, resistance to corrosion and wear resistance also has increased. Cr12 MoV conforms to high requirements of the mold material in hardness, abrasion resistance, anti-corrosion, as a kind of widely used cold work die steel, it is used to manufacture large sectional area and complex shape of cold punching die.Cr12MoV has high hardness, especially for raise the precision of mold molding, the after heat treatment of Cr12 MoV hardness is greater than or equal to 60 HRC. Using traditional cutting manner is very difficult to be machined. Based on this, the use of WEDM cutting Cr12 MoV become the best choice. WEDM is the use of pulse discharge corrosion material, the use of numerical control technology on the workpiece cutting and forming, so not only to meet the difficult process of mold materials, but also for the demands of manufacturing precision. Thus, researched the influence on material removal rate and surface roughness of process parameters(the electrical parameters dominates, including pulse width, pulse gap, peak current and gap voltage)for machining Cr12 MoV with WEDM, in order to achieve electrical parameter optimization selection, and improve the WEDM machining efficiency and surface quality of Cr12 MoV.By using the single factor test method, the influence of various electrical parameters on the material removal rate and surface roughness of Cr12 Mo V is obtained by changing the electrical parameters of the WEDM. On this basis, using the finite element analysis software ANSYS, and mechanism of WEDM, establishing physical model and mathematical model and dividing reasonable grid, confirming distribution of energy in the discharge channel, applying load and solving, the temperature field distribution of the WEDM machining Cr12 MoV steel is obtained, to forecast effect of changing of peak current on surface roughness. The thickness of white layer was considered and modify the simulation pit depth value, matched with the real processing consequence, obtained more consistent correction dent depth and surface roughness curve, demonstrated that reasonable electric parameters can be selected through simulated temperature field of electric spark machining.By using the method of orthogonal experiment, L16(45) orthogonal table was determined by setting a reasonable levels of factors what be investigated and designing table header, and got the test results. Test results were used to range analysis and variance analysis to explore primary and secondary sequence and significance of influence what was pulse on time, pulse off time, peak current and the gap voltage of the WEDM effected on material removal rate and surface roughness. Based on the orthogonal test results, material removal rate and surface roughness was analyzed after dimensional normalization, and the correlation value was calculated. A set of electrical parameters with the largest correlation value was choosed as the optimal parameter combination. The value of the pulse on time is 10 μs, the pulse off time is 20 μs, the peak current is 2 A, the gap voltage is 3 V. The experimental outcomes was verified and demonstrated that optimized parameters can achieved the desired results, and the optimization issue of the parameters was solved.In a word, through a series of experiments and analysis methods, the selection and optimization of the electrical parameters of WEDM machining Cr12 MoV were studied, which provided theoretical guidance for the practical production.