差速器壳体铸件冒口根部黑斑产生原因及防止措施  

Reasons and Prevention Measures for Black Spots at the Riser Roots of Differential Gear Housing Castings

作　　者：史继之 邢继伦 张广勤 吴少旗 杨超 SHI Ji-zhi;XING Ji-un;ZHANG Guang-qin;WU Shao-qi;YANG Chao(Xuzhou XCMG precision industry Technology Co.,Ltd.,Xuzhou 221600,Jiangsu,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Inner Mongolia Research Institute,Shanghai Jiao Tong University,Hohhot 010010,Inner Mongolia,China)

机构地区：[1]徐州徐工精密工业科技有限公司,江苏徐州221600 [2]上海交通大学材料科学与工程学院,上海200240 [3]上海交通大学内蒙古研究院,内蒙古呼和浩特010010

出　　处：《铸造》2025年第3期392-396,共5页Foundry

基　　金：内蒙古自治区上海交通大学科技合作专项“科技兴蒙”上海交通大学行动计划(2023XYJG0001-01-01);徐工精密-上海交通大学联合攻关项目“基于人工智能技术的铸件成本优化”(SA0501495)。

摘　　要：QT450-10球墨铸铁差速器壳体铸件加工后在冒口位置出现黑斑,呈现圆环形。去除冒口后观察铸件和冒口颈的断面颜色,断面中心区域均呈现亮灰色,周边区域均呈黑斑状;金相组织观察显示,黑斑区石墨形态呈片状,黑斑区与亮灰色区交界处石墨形态呈蠕虫状,亮灰色区为正常球状石墨。结合所用冒口和实际生产状况,更改了冒口形状和铁液成分,经过试制,工艺改进后铸件冒口根部断面颜色均匀,加工后均未发现黑斑缺陷,石墨形态良好。Black spots appeared in the QT450-10 ductile iron differential gear housing castings after machining,showing circular shapes.Observing the cross section colors of the castings and riser necks after cutting off risers,the center region of the cross section showed bright gray color,and the surrounding areas showed black porphyritic texture.Metallographic structure observation shows that,the graphite morphologies at the black spot area present flake,the graphite morphologies at the junction of black spot and bright gray area present worm-like,and the graphite morphologies at bright gray area present normal spheroidal.Combined with the risers used and the actual production conditions,the riser shape and molten iron composition were modified.After trial production,the riser root section colors of the castings through process modification were uniform,no black spot defects were found after machining,and the graphite morphology was good.

关 键 词：球墨铸铁 黑斑 发热冒口 石墨形态 球化衰退 

分 类 号：TG245[金属学及工艺—铸造]