Application of modeless NC machining technology to large steel castings

Combined with a specific case of large-scale steel casting processing and manufacturing, the application of modeless NC processing technology in metal casting manufacturing is discussed. The selected case is a typical large-scale steel casting, which is the main water pump in the main circuit of nuclear power plant, and the component name is reactor coolant pump (PCR).

The casting is one of the most important components in the main circuit of nuclear power plant and the main power unit of medium pressure water reactor coolant system in the process of nuclear power production. It is necessary to rotate the impeller in the pump to complete the internal circulation in the circuit under the working environment of high radiation, high temperature and high pressure, so as to transfer the human energy in the reactor core to the steam generator.

The cooler pump model selected in the study is the general model of domestic nuclear power plants, with maximum length of 3460mm, maximum width of 3100mm, maximum height of 2360mm, maximum thickness of 430mm, blank weight of 40t and material of Z3CN20-09M stainless steel.

The equipment is a RCCM nuclear first-class component, which has high requirements for its performance and comprehensive mechanical characteristics of materials. Under the traditional casting process, at least a plurality of production and processing schemes must be determined before manufacturing, and then manufacturing, pouring and commissioning can be carried out continuously to find the best parameters. If the mold opening process is used, the production cycle and mold manufacturing cost will be uncontrollable, The manufacturing cost may greatly exceed the expectation, and at the same time, it also needs to bear the die scrapping risk caused by unqualified process. Therefore, digital modelless manufacturing and processing is a more reasonable manufacturing and processing process for both cost control and manufacturing safety.