Jiao A.-Y.,University Of Science And Technology Liaoning |
Shen S.-L.,University Of Science And Technology Liaoning |
Deng J.-W.,Tianrun Crankshaft Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2015
It was found that the detection value of carbon content in electric furnace pig iron sample by spark source atomic emission spectrometry was lower than that obtained by infrared absorption method. The microstructure for spectrum sample and tablet sample of pig iron were observed. The results showed that the spectrum sample contained much free graphite. In other words, the white level of spectrum sample was lower than that of tablet sample, which directly caused its lower determination result of carbon content. Therefore, the preparation process of spectrum sample was analyzed. It was found that the chilling step was the main factor to influence the white level. To improve this condition, four modification measures were conducted, i.e., enhancing the cooling rate of cast sample, increasing the temperature of liquid iron for cast, adding anti-graphitization elements and selecting appropriate analysis position. The verification experiments indicated that the spectrum samples with improved method achieved ideal white effect. The difference of determination results of carbon content by spark source atomic emission spectrometry and infrared absorption method was not higher than 0.02%, which could meet the requirements for production. ©, 2015, Central Iron and Steel Research Institute. All right reserved.
Yang S.,Shandong University of Technology |
Cong J.,Tianrun Crankshaft Co. |
Sun H.,Tianrun Crankshaft Co. |
Li D.,Beijing University of Posts and Telecommunications |
And 2 more authors.
69th World Foundry Congress 2010, WFC 2010 | Year: 2010
In order to improve strength, toughness, casting quality of the nodular cast iron crankshaft and reduce scrap, liquid eutectic point control, the nodulization process, non-core casting technology, tin - copper alloying and structure uniformity were studied. Using the studying results, high strength and toughness SG iron crankshaft have been successfully produced and shrinkage defect is decreased to O. 19% .
Yang S.-Y.,Shandong University of Technology |
Cong J.-C.,Tianrun Crankshaft Co. |
Sun H.-T.,Tianrun Crankshaft Co. |
Yu H.-M.,Tianrun Crankshaft Co. |
Ci W.-H.,Tianrun Crankshaft Co.
Zhuzao/Foundry | Year: 2012
The scabs and the blowholes easily existed in ductile iron crankshaft castings by straight half parting. In order to solve the problems, we design new foundry technology that has no cores by curved parting and concave-convex mould board, which simplifies working procedures, avoids scabs and blowholes, and reduces costs. In order to get uniform microstructure, the technology and the equipments of normalizing treatment with suspended type rotating spray cooling were successfully developed, which made the heat stress and the structural stress of workpieces more uniform, reduced the deformation of workpieces, and improved crankshaft quality. Multi-cylinder crankshafts can be steadily produced.
Deng J.,Tianrun Crankshaft Co. |
Cai C.,Tianrun Crankshaft Co. |
Gao F.,Tianrun Crankshaft Co. |
Wang L.,Tianrun Crankshaft Co.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2015
Morphology and chemical composition of crankshaft crack for 3.8L car were analyzed. The results show that the crack is resulted from quenching. The main reason for the crack forming are poor uniformity of iron liquid and elements segregation along the grain boundary that results in a lot of retained austenite and cementite networks, which separates the matrix. The retained austenite transformed into martensite at the later stage of quenching and tempering, which causes crankshaft expansion, and the excessive tensile stress on the surface of the crankshaft, that induced the cracking. ©, 2015, Chinese Mechanical Engineering Society of Heat Treatment. All right reserved.