Cutting Parameters Optimization Of Die Steel For Automobile Covering Panel And Database Development

In order to improve production efficiency, machining precision and the tool life in machining process of die steel for automobile covering panel, the material and structure of tools and cutting parameters were optimized in high speed rough and finish ball-end milling Cr12MoV die steel. The optimization model of cutting parameters was established, and the B/S (Browser/Server) structure-based high speed cutting database system of die steel for automobile covering panel was designed and established. Experimental data were provided for high speed milling Cr12MoV die steel.The cutting performance of DUET JC8015asymmetric coated cemented carbide tool was studied in rough ball-end milling the annealed Cr12MoV die steel. The results showed that with the optimal cutting parameter of v=160m/min,f=0.24mm/r, ap=2mm, ae=5mm, the amount of tool wear rate reached to the minimum in this study. The influence on the tool wear rate decreased in the order of the feed>the cutting speed>the radial depth of cut>the axial depth of cut>the interaction between the cutting speed and the axial depth of cut. The cutting force increased with an increase in the cutting speed, the axial depth of cut, the radial depth of cut and the feed. The empirical equation of cutting force was set up.The cutting performance of different tools was studied in rough ball-end milling the annealed Cr12MoV die steel at a tool-axis inclination angle of zero. The results showed that the flank wear of DUET JC8015asymmetric coated cemented carbide tool was the smallest, and the flank wear width of the major insert of Sandvik PGC4020symmetrical coated cemented carbide tool was almost equal to that of the major insert of Sandvik PCT530symmetrical cermet tool. The anti-bonding capacity of the cemented carbide tool was weaker than the cermet tool. The main failure mechanisms of the cemented carbide tool were flank adhesive wear, and the main failure mechanism of the cermet tool was flank abrasive wear. The TiN coating produced severe adhesive wear in milling the die steel, while the TiAIN coating could slow down the tool wear effectively. The asymmetric tool increased the edge strength and the symmetrical tool reduced the edge strength. Therefore DIJET JC8015asymmetric coated cemented carbide tool was recommended in rough ball-end milling the annealed Cr12MoV die steel. The cermet matrix, TiAIN coating and asymmetric tool structure were recommended.The cutting performance of different tools was studied in rough ball-end milling the annealed Cr12MoV die steel at a big tool-axis inclination angle of45°. The results showed that the flank wear of DUET JC8015asymmetric coated cemented carbide tool was the smallest, and the flank wear width of Sandvik PCT530symmetrical cermet tool was larger than that of Sandvik PGC4020symmetrical coated cemented carbide tool.The cutting parameters were optimized when DIJET JC8008asymmetric coated cemented carbide fine tool and Sandvik GC1010symmetrical coated cemented carbide fine tool were used in finish ball-end milling the hardened Cr12MoV die steel. The influence of cutting parameter on tool life was analyzed, and those tools in finish ball-end milling the hardened Cr12MoV die steel was selected and commended. The results showed that when JC8008tool was used in finish milling the hardened Cr12MoV die steel, the optimized cutting parameter was v=160m/min,f=0.45mm/r, ap=0.45mm and ae=0.5mm, and the influence on the tool life decreased in the order of the radial depth of cut>the axial depth of cut>the feed>the cutting speed. When GC1010tool was used in finish milling the hardened Cr12MoV die steel, the optimized cutting parameter was v=120m/min, f=0.45mm/r, ap=0.6mm and ae=0.5mm, and the influence on the tool life decreased in the order of the radial depth of cut>the cutting speed>the axial depth of cut>the feed. The main failure mechanism of the coated cemented carbide fine tool was edge chipping caused by impact cutting force, and DIJET JC8008asymmetric coated cemented carbide fine tool was recommended in finish ball-end milling the hardened Cr12MoV die steel.The influence of cutting parameter on surface roughness was analyzed, and the theoretical model of path-interval cusp height was set up. The results showed that the surface roughness was mainly affected by feed-interval cusp height and path-interval cusp height. Radial depth of cut had the greatest impact on the surface roughness Ra and a smaller radial depth of cut was recommended to reduce the surface roughness. The tool-axis inclination angle was optimized when DIJET JC8008asymmetric coated cemented carbide fine tool was used in finish ball-end milling the hardened Cr12MoV die steel.The results showed that when the tool-axis inclination angle was from20°to30°, the tool life was longer and the surface roughness was lower.The tool wear models based on exponential function and MATLAB neural network were established in finish milling the die steel, and the optimization model of cutting parameters based on NSGA-Ⅱ (Non-dominated Sorting Genetic Algorithm-Ⅱ) in MATLAB was applied to optimize the cutting parameters in finish ball-end milling the hardened Cr12MoV die steel. The results showed that the forecasting accuracy of the model based on MATLAB neural network was higher.The conceptual design and logical design of the database were completed, and the E-R diagram and logic model of the database were established. The architecture, development environment and development tools of the database were selected. The database was integrated with the optimization model of cutting parameters based on MATLAB. The high speed cutting database system of die steel for automobile covering panel was designed and established successfully.