Deformation And Its Control Of ZL205A Shell Cylindrical Castings

In this paper, the distribution of stress and the rules of deformation of a frame-shape casting under different controlled conditions has been studied with the help of simulation software Pro CAST. According to the rules of the deformation of the frame-shape casting, a temperture controlled method which can control the cooling conditions and reduce the temperature difference of the casting by heating or cooling a part of the casting was designed and studied to reduce casting residual stress and deformation. On this basis, the rules of deformat ion of a thin-walled cylindrical shell casting with ZL205 A alloy has been studied. And this temperature control method was applied to control the deformation of the cylindrical shell castings.Stress-strain curves in low and high temperature of ZL205 A alloy was obtained through thermal compression deformation experiments. Through the experiments, high temperature mechanical performance parameters which was used to simulate the stress field in Pro CAST has been got and the material database used in the simulation has been created.The deformation rules of the frame-shape casting without under temperature controlled conditions were studied and analyzed. According the results, a method that heating the thin bar of the frame-shape casting by heating wire or cooling the thick bar of the frame-shape casting by cold air was designed. And the effects of heating temperature, local preheating time and cooling air flow rate on the stress and the deformation of the frame casting was studied. The results show that as long as temperature difference between the various parts of the casting can be reduced the deformation of the casting caused by thermal stress of castings can be reduced.Based on the simulation research, some frame-shape casting experiments was carried out. The temperature curves measured by the thermocouple in the experiments are consistent with the simulation results. The residual stress of the frame-shape casting were measured by ultrasonic method. And it was found that the residual stress of those frame-shape castings whose temperature was controlled before decreased a lot. It verified the feasibility of temperature controlled methods to control the deformation of castings.The stress distribution and deformation regularity of a thin-walled cylindrical shell casting was studied. It was found that different degrees of uneven shrinkage deformation and warping deformation produced in the circumferential direction, radius direction and height direction of the cylindrical casting. According to the deformation characteristics of the cylindrical casting, a temperature controlled scheme of cylinderical casting was carried out. The effects of the heating temperature, preheat time, cooling air flow rate, sand shake-out temperature on the deformation of the cylindrical casting were simulated studied by using orthogonal experimental method and the best deformation control scheme was got finally.