论文部分内容阅读
某发电厂磨煤机轴在运行约10 000 h后断裂,该轴材质为40Cr钢,断裂位置在直径变径处。本文通过宏观形貌分析、化学成分分析、力学性能检验、显微金相和扫描电镜断口观察,对该断裂轴进行了失效分析。1断裂原因分析1.1宏观观察对断裂轴进行宏观观察,断裂位置位于直径变截面R圆角处,R圆角较小,断口较平整,无明显塑性变形,属于一次脆性断裂。断口宏观形貌如图1所示,从断口宏观形貌可以看出断裂起始于轴表面,断裂源区边缘有明显挤压痕迹;源区及扩展区较平坦,呈灰白色,无明显的棱线;断裂区有明显撕裂棱。
Pulverizer shaft of a power plant ruptured after about 10,000 h of operation. The material of the shaft was 40Cr steel and the fracture location was at the diameter reduction. In this paper, failure analysis of the fracture axis was carried out by macroscopic morphology analysis, chemical composition analysis, mechanical property test, microstructure and SEM observation. 1 Analysis of fracture 1.1 macro observation Macro-observation of the fracture axis, the fracture location is located in the R-diameter variable cross-section of R rounded corners smaller, relatively flat fracture, no significant plastic deformation, a brittle fracture. The macroscopic appearance of the fractures is shown in Fig.1. It can be seen from the macroscopic morphology of fractures that fractures originate on the surface of the fractures and there are obvious signs of extrusion at the edges of the source rocks. The source and extension zones are relatively flat and gray-white with no obvious edges Line; obvious tearing rupture zone.