Application of numerical modelling results to analyze and improve the industrial process of valve forging production

摘要

The article discusses the application of the results of numerical modelling for a multi-variant simulation of the process of producing a chromium-nickel steel valve forging designed for truck engines. A forging of this type is manufactured in two operations: coextrusion of a long shaft, followed by finishing forging of the valve head. The main problem in this process is a relatively low tool durability; in the first extrusion operation, we observe premature wear of the die, whereas in the second operation, a low durability of the punch can be noticed, which is connected with the intense abrasive wear as well as adhesion of the material of the forging to the tools. The numerical modelling was carried out with the use of the Forge 2.0 calculation packet in order to analyze the effect of the temperature conditions and friction. A detailed analysis was performed on the second forming operation - hot forging of a head valve, as, in the industrial process, due to insufficient control of the key technological parameters, slight changes of the tribological conditions might occur, which affect the properness of the whole process. The multi-variant analysis of the forging process with the use of numerical modeling provided a lot of valuable information regarding changes in key parameters difficult to obtain during the analysis of the industrial process and their mutual influence on each other, such as: distribution of temperature fields, pressures and parameters determining wear, as well as forging force courses. On this basis, it is possible to introduce without major worry significant changes in the industrial process in order to obtain its stability and repeatability, and increase the durability of forging equipment.