摘要: |
液压油缸在整机装配过程中缸筒焊接接头焊缝开裂,取断裂的焊接接头进行形貌观察、成分分析、扫描电镜观察、金相分析及能谱分析。结果表明:由于焊前预热不到位、焊后保温不及时,导致缸筒焊接接头焊缝热影响区出现马氏体组织,在应力腐蚀作用下,形成脆性裂纹,后期焊接热影响区在残余应力和腐蚀介质的作用下,裂纹逐步扩展发生断裂。 |
关键词: 40Cr钢焊接;断裂;应力腐蚀 |
基金项目: |
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Fracture Failure Analysis of Welded Joint of Hydraulic Cylinder |
Li Teng1, Gao Yang2, Wu Liming1, Yang Shaohua2, Yuan Li1, Zhao Yan1
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1. Shanxi Aerospace Qinghua Equipment Co., Ltd., Changzhi 046012;2. Representative Office of Rocket Force, Changzhi 046012
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Abstract: |
During the assembly process of the hydraulic cylinder, the welding seam of the welded joint of the cylinder barrel cracked. The broken welded joint was analyzed by morphology observation, composition analysis, scanning electron microscope observation, metallographic analysis and energy spectrum analysis. The results show that the martensite structure appears in the weld heat affected zone of the cylinder welded joint due to the lack of preheating before welding and the delay of heat preservation after welding. Under the action of stress corrosion, brittle cracks are formed. Under the action of residual stress and corrosive media, cracks gradually expand and fracture occur in the welding heat affected zone in the later stage. |
Key words: 40cr steel welding;fracture;stress corrosion |