2014.06.08 Shanghai Kai Fu Industrial Co. Ltd. (sales of P20 die steel www.xfmjgy.cn) information: with the development of the automobile industry and the industry competition intensifies between comprehensive mechanical performance and price, the automobile castings of the increasingly high demand, production and Application Research of so high ductile cast iron, has a very positive significance to improve the the product quality and competitiveness. In this study, starting from the actual production, by means of chemical composition, control of casting intensifying inoculation, especially the amount of adjustment of Mn elements of alloy, as cast pearlite and ferrite matrix ductile iron mixed with high grade, in reducing the production cost at the same time, greatly improve the quality of castings, and verified in transit singleton wheels production site. L manganese in ductile iron manganese can impede the decomposition of cementite and ferrite, in ductile iron with manganese and sulfur due to few, and mainly plays the role of stabilizing pearlite and carbides, the as cast pearlite increased and refinement. Manganese is also can be dissolved in ferrite, to strengthen the role of ferrite. 2014.06.08 Shanghai Kai Fu Industrial Co. Ltd. (sales of P20 die steel www.xfmjgy.cn) information: so, in casting production practice of ductile iron castings of high grade state, the amount of control is very important manganese, general process control in 0.4% - 0.6%, and is generally considered too high content of manganese in ductile iron segregation, will reduce the impact toughness of castings. In this study, the traditional production of breakthrough in ductile iron manganese amount limitation, used to increase the amount of manganese, comprehensive mechanical properties to meet the requirements of as cast high grades of ductile cast iron. 2 test results and analysis of 2.1 test results of manganese content changes on the properties and microstructure of ductile iron sample mechanics as shown in table L. From Table L specimens of Cll, C12, D11 can be seen, the manganese content increased from 0.48% to 1.2%, the strength is increased from 473MPa to 738MPa, the hardness is increased from HBl70 to I - IB240, while the elongation decreased from 21.86% to 5.3%. Therefore, in raising the carbon content, make sure the ball, increase breeding conditions, the manganese content in O.7 and O.9% can produce QT500 - 10, QT550 - 7, the manganese content in the 0.9 - 1.1% range can produce QT600.5, QT700.3. Impact of changes in table lMn addition on the mechanical properties. 　　2014.06.08上海偕富实业有限公司（销售P20模具钢www.xfmjgy.cn）的资讯：随着汽车工业的发展和产业间竞争的加剧，对汽车铸件的综合机械性能及性价比的要求越来越高，因此高牌号铸态球墨铸铁的生产应用研究，对提升产品质量和竞争力具有十分积极的意义。本研究从生产实际出发，通过控制铸件的化学成分，强化孕育，尤其是调整Ｍｎ元素的合金化加入量，获得铸态珠光体－铁索体混合基体高牌号球墨铸铁，在降低企业铸件生产成本的同时，提高铸件的产品质量，并在全顺单胎轮毅的生产现场得到验证。ｌ锰在球墨铸铁中作用锰能阻碍渗碳体和铁素体的分解，在球铁中由于锰很少与硫结合，而主要起稳定珠光体和碳化物的作用，可使铸态下珠光体增加并细化。锰还可固溶于铁素体，起强化铁素体的作用。