TR Company Casting Division For Quality Of Ductile Iron Control Methods Of Research

TR Company is the largest professional crankshaft production enterprises, including heavy truck, medium-sized truck, light truck, car and other kinds of crankshaft castings. Crankshaft is the key component of auto parts and is the most typical nodular cast iron castings. Crankshaft is the earliest casting researched and developed in China and applied widely.With the development of new technology, higher requirements for materials quality of cast iron are put forward. The requirements include not only high strength and good toughness, but also good processing performance and good service performance and stable quality. That is, the requirements are put forward for the comprehensive performance and stability of the material quality. Although our country is the nodular cast iron producer, not power. The materials composition, microstructure and performance level is lower than the developed industrial countries, mainly in the ductility level and stability of the nodular cast iron. The compositions fluctuate largely:Domestic C is under±0.15%, Si is under±0.2%and C is under±0.05%, Si is under±0.1%abroad. As-cast nodular cast iron is applied generally and yield strength is examined. However, quite a number of nodular cast iron also needs heat treatment at home. So we should strengthen the research on the method to control molten iron quality.This paper analyzes the current quality status of nodular casting iron smelted with the electric furnace in TR Foundry Division and the problems exist in composition quality control of molten iron. And on this basis, electric furnace melting flow chart, standard work instruction book, the key quality control points and the compositions of molten iron are elaborated and analyzed systematically. Relevant measures are put forward to ensure the molten iron quality control of nodular casting iron production. Finally, the research theory is applied in cases and analyzed systematically. The nodular casting iron production molten iron quality control system in TR Company Foundry Division is summed up. The casting defects in nodular casting iron production for compositions, such as sand inclusion, shrinkage and choke are solved effectively.