120阀紧急活塞杆扭矩校核及异常断裂分析  

Torque Checking and Abnormal Fracture Analysis of Emergency Piston Rod in 120 Type Valve

作　　者：张成国[1] 赵亚栋 姚小沛[1] 刘宝安[1] 王建国[1] 

机构地区：[1]中国铁道科学研究院机车车辆研究所,北京100081 [2]中国北车集团齐齐哈尔轨道交通装备有限责任公司,黑龙江齐齐哈尔161002

出　　处：《铁道机车车辆》2014年第2期101-104,共4页Railway Locomotive & Car

基　　金：科技部"轨道交通制动系统制造技术研究"项目(2012EG123029)

摘　　要：对120阀紧急活塞杆进行了扭矩强度校核及实物验证,在符合图样设计要求和正常组装的情况下,紧急活塞杆的断裂扭矩高于组装要求力矩,但极端情况下裕度不大;建议对紧急活塞杆所用的铜合金棒材,明确优先执行GB/T 4423-2007以便在极端情况下保留较大的裕度。对异常断裂与试验用活塞杆进行了宏观断口、显微组织的分析,异常断裂紧急活塞杆无明显塑性变形,晶粒组织粗大,这种组织会导致材料力学性能下降;建议在紧急活塞杆制造过程中加强料头、料尾及批次质量稳定性的控制。Allowable torque of emergency piston rod of 120 type valve was checked and further verified experimentally in this paper. In case of conforming with designing requirements and normal assembly of emergency piston rod, allowable torque is higher than the torque required in assembly, however, in extreme cases the margin of safety seems not enough. It is proposed that for the raw rods machining into the emergency piston rods should be clearly defined to conform to the Standard GB/T 4423- 2007 to reserve a relatively large margin of safety in extreme cases. Macroscopic fracture and microstructure of the piston rod tested here and abnormal fractured were analyzed comparatively. Abnormal fractured piston rod fractured flush without obvious plastic deformation, and its microstructure grains coarsened severely, and such coarse grains microstrueture would deteriorate the mechanical properties of materials. It is proposed that manufacturers should also strengthen the quality control in the emergency piston rod manufacturing process, especially pay attention to the material head, and tail.

关 键 词：120阀 紧急活塞杆 断裂 许用扭矩 显微组织 

分 类 号：U270.351[机械工程—车辆工程]