防止球铁件缩松新工艺

Study on New Technology to Prevent the Shrinkage of Ductile Iron Castings

将自主研制的球墨铸铁复合除缩剂添加到有缩松缺陷的曲轴试块中,改变除缩剂的成分和加入量进行优化和比较试验,对其断面进行宏观分析,观察其金相组织变化,进行硬度测试。同时在工厂对有缩松缺陷的5028炉盘进行了同样的试验。结果表明,除缩剂A加入量为6 g时,曲轴试块的缩松缺陷向上表面集中,缩松面积明显减少;加入量为2.4 g时,铸件5028炉盘内部缩松缺陷可完全消除。并且除缩剂的加入几乎不影响石墨的球化程度及铸件的硬度。

Self-developed shrinking eliminating agent for ductile iron was used to prepare Crank test block with shrinkage defects, by changing the composition and additions of the eliminating shrinking agent to optimize the effect with the comparison, the experiments on macro analysis on the crosssection microstructures and hardness were performed. The same test also conducted to the trial heat No. 5028 in the factory. The results show that, when the eliminating shrinking agent addition is 6 g, shrinkage defects concentrate at near the up surface, but the shrinkage areas are significantly reduced ; when its addition is 2.4 g, the shrinkage defects of castings made from heat No. 5028 can be eliminated completely. And it almost doesn＇t affect the degree of graphite nodularity and the hardness of castings.