采用覆砂铁型铸造工艺试制了美国EMD高速机车用的球墨铸铁连杆.通过合理设计浇注系统,严格控制化学成分和浇注工艺,获得了满意的结果:(1)铸件的表面质量及尺寸精度均满足技术指标要求,球化级别达到2级；热处理后铸件本体基体组织中铁素体体积分数达94％；(2)铸件力学性能达到美国ASTM A 536-84标准,符合牌号65 -45 - 12标准要求,即抗拉强度≥448 MPa,屈服强度≥310 MPa,伸长率≥12％,-20℃低温冲击值≥12 J/cm2.%The ductile iron connecting rod used for EMD high speed locomotive imported from United States was produced in the trial way with the sand-coaled permanent mold casting process. By designing proper gating system,and by strictly controlling chemical composition, iron melting and pouring process,satisfied results were obtained: (a)Both the surface quality and dimensions met the technical requirements, and nodularity reached grade 2; and the ferrite volumetric fraction in the matrix structure of the as-heat-treated casting body reached 94% ; (b)The mechanical properties of the casting met the requirements of grade 65-45-12 specified by the US standard ASTM 536-84,i.e. tensile strength ≥448 MPa,yield strength ≥310 MPa, elongation ≥ 12%, low temperature(-20℃ ) impact toughness≥ 12 J/cm2.
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