Research On The TR Method Forging Process Of Heavy Crankshaft And Dynamic Recrystallization Simulation

Heave crankshaft is the key component of diesel engine. Crankshaft work situation is extremely complex, and it's manufacturing quality impacts diesel engine performance and reliability. With shipbuilding, petroleum, power generation, diesel locomotives develop rapidly these years, the market need large numbers of high-quality, full-sized fibers diesel engine crankshafts. There are great demands in the domestic and international market for large and medium-sized crankshaft.Crankshaft converts gas pressure from side rod into torque, which acts as the driving force and output. At present, due to the large size of crankshaft, greater weight, complex shape, difficult deformation, the closed die forging may be difficult to produce this heavy crankshaft. Heavy crankshaft forging process consists of free forging and upsetting. The upsetting-bending process of the heavy crankshaft with continuous grain flow has greatly improved the crankshaft fatigue, and improves the utilization of metal machining efficiency, which is superior to free forging. According to the differences of the devices principle and structure, there are different forming methods, such as RR method, TR method, the NRR, TR method based on the improvement of RR, TR method and the horizontal cross-orthogonal plane forging method et al. The RR and TR upsetting-bending process have been widely used abroad, but there are some inherent problems to be resolved in the process.In this paper, the CSR Locomotive Company 3,600 MN hydraulic machine equipped with the TR forging device is subject investigated, the TR forming method was simulated by the FEM. For the new developed model of the DN8330 crankshaft, the heavy crankshaft forging process was simulated by software Deform-3D, through which the cause of typical forming defects was analyzed and some effective measures was proposed to prevent defects and the key parameters and die structures were optimized. Aim to the serious subfilling of the crank arm, the construction of"constrained wing"was presented to form the favorable die filling instead of increasing the forging size. The forming load of the heavy crankshaft was researched and optimized based on BP Neural Networks. The maximum forming load was decreased by use the reasonable parameters. Due to the higher strength and stiffness of the crankshaft, the dynamic recrystallization was simulated by the FEM and the effect of crankshaft forging process on improving the microstructure and properties was researched. Through research of this topic, the process of forming crankshaft TR method, plastic finite element, numerical simulation technology and die with CAD technology were combined, to shorten the product development and manufacturing cycle and reduce the production cost and make the enterprise bring good economic benefits et al. The results of research provides theoretical and practical basis for the productions of the same crankshaft, the new model forming process of the development and associated mold design and could be directly used for the production of guidance.