Surface Quality And Machining Accuracy For High Speed Milling Of5CrMnMo Forging Die

In recent decades, due to its high production efficiency, machining accuracy and lower cost, CNC milling technology is gradually replacing the traditional EDM technology in the field of precision forging die manufacturing. The surface quality and machining accuracy of precision forging die will be directly reflected in the quality of forgings. Therefore, in order to provide the guidance of selecting the appropriate processing parameters, the research of cutting parameters that influence of forging die surface quality and machining accuracy is particularly important to improve the quality of forgings.The research of cutting process parameters on the surface roughness of forging die is gradually increased, the domestic and foreign scholars carried out a large number of optimization process or studied the method to improve process efficiency. The research methods include simulation studies and experimental studies. However, few scholars have studied the relationship between process parameters and geometric accuracy. Similarly, the research of these factors on the production time and production efficiency is very limited.In this work, throughout the investigation of the common forging die forging products, three surface profiles are found those are most common in the forging die applications, which are the horizontal plane, the transition surface whose fillet radius larger than2mm, and the inclined surface whose draft angle is from3°to7°. As a result, the solid geometry model of the forging die’s typical profile is built in Pro/E to study the main factors that is the relationship between cutting parameters (cutting speed, feed rate and depth of cut) and the forging die size precision. The experimental research is adopted in this study, the three-factor orthogonal test is used to design24combination of cutting parameters. The tool steel alloy of5CrMnMo is selected as the experiment material for the forging die test. Both rough milling and precision milling are completed on the same processing conditions such as the tool, the tool trajectory, etc. All the factors are carefully selected, in order to ensure the test data regularity, targeted and availability. Subsequently, the coordinate measuring instrument is used to measure the actual contour of each cavity, and the data are imported in Pro/E to obtain the error statistics and analysis through the comparation between the theory cavity and the actual cavity, so as to obtain the regularity that the cutting parameters influence on the dimensional accuracy. A mathematical model for error prediction, and calculate the relevant formula is then established. The prediction formula established by this study is proved by the verification tests, and this shows that the prediction formula have certain guiding significance for the actual machining process. The thesis also uses the same method to research the relationship between the cutting parameters and the surface quality.