地铁电机悬挂梁疲劳开裂分析及改进措施  

Analysis and Preventive Measures of Fatigue Cracking of Suspension Beam for Metro Motor

作　　者：徐贵宝 XU Gui-bao(CRRC Qishuyan Institute Co.,Ltd.,Changzhou 213011,Jiangsu,China)

机构地区：[1]中车戚墅堰机车车辆工艺研究所有限公司

出　　处：《铸造》2019年第12期1411-1416,共6页Foundry

摘　　要：从宏观特征、微观组织等方面,分析了地铁直线电机悬挂装置用关键薄壁铸钢件发生开裂的原因,发现孔洞和显微缩松是裂纹源,在震动交变载荷作用下,导致了裂纹的形成和扩展,使工件产生低应力高周疲劳失效开裂。基于工艺方案模拟的结构,优化了悬挂梁的铸造工艺,并通过提升材料性能、加强过程控制等改进措施,消除了关键部位的孔洞裂纹源,解决了疲劳开裂问题,提高了铸件质量与使用寿命,确保了行车安全。The cracking reasons of the key thin-walled steel castings for the suspension device of metro linear motor were analyzed from the aspects of macroscopic characteristics and microstructure.The shrinkage holes and porosity in the suspension beams were found to be responsible for fatigue cracking since these defects led to the initiation and propagation of cracks under the action of alternating vibration load and make the workpiece produce low stress and high cycle fatigue failure.Based on simulation results of shrinkage cavity and porosity during mold filling process,casting process was improved.In addition,other preventive measures such as improving material performance and strengthening process control were also taken.Finally,the shrinkage holes and porosity defects were eliminated or reduced.Therefore,the problem of fatigue cracking was solved.The improved casting quality and increased service life will ensure the driving safety of metro motor.

关 键 词：薄壁铸钢件 疲劳裂纹 孔洞缺陷 显微缩松 方案改进 

分 类 号：TG142.1[一般工业技术—材料科学与工程]