Research For The Quality Of Heavy Section Ductile Iront Control In TR Company Casting Branch Factory

In recent years, China’s casting yield not only has been on a steady rise but also ranked first steadily in the world for many years,especially the ductile iron’s production growth is the fastest. With the rapid development of heavy machinery, marine crankshafts and other industries had promoted the development and application of Heavy Section ductile iron castings, the market prospect of heavy section ductile iron castings is getting better and better.TR casting branch factory had researched, developed and produced heavy section ductile iron castings including gearboxes, planetary frame, wheels, planet carrier and crank. According to the waste statistics indicated that the main reason of marine crank casting waste is caused by chunky graphite in producing marine crank process of TR casting branch factory. Chunky graphite is a common defect in heavy section ductile iron castings. It has a significant impact on the spheroidization rate and the mechanical properties, so the problem of chunky graphite in heavy section ductile iron castings is the focus of global attention.To solve the problem of chunky graphite, the author takes marine6190cranks as the example, adopts the method of literature synthetic study, the causes and effects conjunction graph, the quantitative investigation and qualitative investigation union law as the main method of research. By collecting relevant theoretical literatures of ductile graphite distortion, summarized research results at home and abroad, and on the basis combining with actual casting production. Comprehensive using the method to study and solve processes of TR casting branch factory’s the heavy section ductile iron castings chunky graphite, for fragmental graphite formation factors of theoretical analysis, the establishment of the solution, solution implementation and curing provide support.Through brainstorming to find out all the factors that influence the formation of stone shaped graphite on heavy section parts, and to sorte out causal association graph according to the interconnectedness of them. Through field test, measurement, verification, investigation analysis, combined with the actual casting production and learned from other informations at home and abroad, can get the main factors for the heavy section ductile iron degeneration. The statistical experiments and test results indicated that the chemical composition, spheroidizing process, inoculation process, pouring temperature process, cooling rate and crafts were main reason to affect chunky graphite generated in heavy section ductile iron.TR company casting branch factory not only studies the production process quality control of heavy section ductile iron castings from technological angle, and breaks through the production process by simply adjusting the process parameters to achieve the goal of quality control methods, quality of personnel, equipment status, quality management methods and systems are carried out in-depth research, production field optimized management, rather than just using the process optimization. Furthermore the study of heavy section ductile iron castings production process quality control is not only for the production of a quality characteristic of a process or perform, and conduct research on aspects of casting the entire production process, key quality characteristics, so as to ensure that the production process integrity, reducing the error between the transfer and accumulation processes to ensure that the study has been optimized at the same time, other key quality characteristics did not decline.Finally elaborated the establishment of the key quality control points, the optimization of technological process, the implementation of preventive and corrective measures, quality files update, staff quality awareness and job skills. The results are the morphology and body performance of heavy section ductile Iron castings graphite were enhanced, and ultimately achieve good economic benefits.