摘要
某工程机械塔式起重机转台连接用10.9级40Cr螺栓在使用1.5年后发生断裂,对断裂螺栓的宏观断口、化学成分、硬度、金相组织、微观形貌等方面进行分析。结果表明：该螺栓在较低公称应力下发生疲劳断裂,断裂原因主要是由于热处理工艺不合理导致的螺栓表面脱碳、整体硬度不符合使用要求。建议严格控制螺栓的热处理工艺,减少脱碳,提高螺栓硬度和强度。
The 10.9 stage 40Cr bolt for connection of the turntable of a mechanical tower cranewas broken after 1.5 years. The fracture bolt was analyzed through macroscopic fracture, chemical composition, hardness, metallographic structure and scanning electron microscope. The results show that, the fatigue fracture of the bolt occurs under low nominal stress condition. The cause of the fracture is mainly due to the deearburization of the bolt surface and the overall hardness lower than the standard requirement caused by the unreasonable heat treatment process. It is suggested that the heat treatment process of the bolts should be strictly controlled to reduce decarburization, improve the hardness and strength of the bolts.
作者
文军
李毅
张东亚
冯坤
WEN Jun;LI Yi;ZHANG Dongya;FENG Kun(Jiangsu Xuzhou Construction Machinery Research Institute, Xuzhou Construction Machinery Group, Xuzhou 221004, China;State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery, Xuzhou Construction Machinery Group, Xuzhou 221004, China)
出处
《热加工工艺》
CSCD
北大核心
2018年第8期249-252,共4页
Hot Working Technology
关键词
塔式起重机
螺栓
疲劳断裂
脱碳
硬度
tower crane
bolt
fatigue fi＇acture
decarburization
hardness
