Casting Process Optimization Of Spray Pump Volute Body And Microstructure Numerical Simulation Of Casting

Spray pump volute body is an important part of a key nuclear plant secondary pump body, directly or indirectly involved in nuclear safety. So the higher quality requirements of the castings were put forward and shrinkage cavity defects such as shrinkage were not allowed to appear. The materials of Spray pump volute casting is domestic brand ZG06Cr13Ni4 Mo, belongs to the cast low carbon martensite stainless steel, gets the characteristics of complex phase change process. In addition, the castings with larger size, wall thickness difference, complex shape and a gradient structure characteristics which bring huge difficulties to the casting forming process, easily to make casting produce hollow defect, reducing the quality of castings, to bring economic loss to enterprises.To meet the needs of factory production, this topic research mainly solves the problem of porosity shrinkage defects when the enterprise produce spray pump volute castings in the actual production. The factory’s original process is introduced in detail in the detail in the paper, finishing and analyzing the numerical simulation of the original process’ filling process and solidification process with the help of the AnyCasting simulation software, predicting casting defects, and combining the plant trial production situation to analysis the reasons of casting defect formation. Putting forward effective measures to improve the original process: changing the riser at the top of casting to heat preservation heat riser; adding insulation blind riser in the middle of casting; optimizing the gating system and improving the size、 numbers and location of the in gate and cross gate; adding irons at the junction between bulge at the bottom of casting and big wall thickness. Using the orthogonal experiment design to study the influence of pouring temperature, pouring time, mould preheating temperature on casting quality and to get the optimal process parameters combination. Optimally designing the chemical composition of ZG06Cr13Ni4 Mo stainless steel in a reasonable scope with the aid of the orthogonal experiment and JMatPro software. Numerical simulation analysis and actual production were carried out on the process optimization scheme. The quality of the casting can meet the requirement of customers. Completing the numerical calculation with CAFE method, studied the influence of pouring temperature on ZG06Cr13Ni4 Mo steel microstructure forming process. Getting the conclusion of this directly impacts the nucleation rate and growth rate.This topic has successfully solved the porosity shrinkage defects problem in the enterprise actual process of production spray pump volute body. Helping enterprise complete the process optimization and offering valuable experience for later similar castings production. Initially completes the casting microstructure simulation research and provides a theoretical basis for subsequent research.