摘要
运营3年的铁路机车日常检修时发现极少部分安装座加强筋焊趾位置焊缝产生裂纹,部分底板因裂纹扩展导致断裂。对安装座各焊接组件在机车运营过程中的受力状态以及裂纹焊接组件的宏观断口、化学成分和显微组织进行了分析。结果表明:由于各部件组焊后内应力未经退火消除且结构上的缺口易产生应力集中,缺口又正处于较为薄弱的焊缝热影响区和最大受力力矩位置,在运营过程中极易产生疲劳裂纹。为减少焊接应力,应从结构上减少焊缝数量并对焊缝去应力退火或结构优化。
After three years of operation,through daily examine and repair of locomotives,there are cracks where in weld joint position of stiffening ribs of few soleplates.Some base plates fractured because of cracks.During the process of locomotive＇s operation,analysising the mechanical condition;macro fracture;chemical composition and microstructure analysis of weld assembly of soleplate.And the result shows： because after each assembly was welded,the stress did not remove by annealing and gap of the structure is easy to produce stress concentration.What＇s more,the gap lied in weaker heat affected zone of weld joint and the most force moment.During the operation,it is easy to create fatigue crack.To decreasing welding stress,the amount of weld joints should be reduced and the structure should be optimized.
出处
《失效分析与预防》
2013年第2期103-106,共4页
Failure Analysis and Prevention
关键词
安装座
焊接应力
疲劳裂纹
结构优化
installation base
welding stress
fatigue crack
structural optimization
