冷拔油缸管失效原因分析及探讨

采用冷拔+刮滚工艺生产的45钢成品油缸管,使用11 h后,在20 MPa左右的压力下发生贯穿性开裂。研究开裂断口形貌、腐蚀产物成分、力学性能、微观组织等,分析该油缸管的开裂原因。分析认为:受去应力退火温度偏低、网状铁素体组织等综合因素的影响,45钢油缸管的塑性和韧性下降、脆性增加,导致其耐压性能下降,从而造成开裂。

Analysis of Reason for Cracking of Cold-drawn Hydraulic Cylinder Pipe

Addressing the fact that the finished 45 steel hydraulic cylinder pipe as made with the process of colddrawing plus scraping-rolling develops through-cracking after being used for 11 hours under about 20 MPa pressure,the reason for the said cracking is analyzed by means of studying such aspects as fracture morphology, composition of the corrosive product,mechanical property and microstructure,etc. It is regarded via the analysis that affected by such comprehensive factors as rather low temperature for stress-relief annealing process and reticular ferrite microstructure, etc.,both the plasticity and toughness of the 45 steel hydraulic cylinder pipe are reduced,whereas its brittleness is increased,which leads to reduction of the pressure resistance as resulting in the said cracking.