热网管失效原因分析

Failure Analysis of Heat-SupplyyNetworkPipe

针对某热电厂Q235B热网管发生爆管的问题,通过对不同爆管区域取样进行光学显微镜、扫描电镜等微观分析和拉伸性能、冲击性能检测。结果表明:在管道内交变载荷的作用下,在接头上的未焊透、夹渣、气孔等缺陷部位产生应力集中,从而造成裂纹的萌生和扩展,最终引起疲劳断裂。

In view of the burst problem of Q235B heat-supply network pipe in a thermal power plant,the analysis by optical microscope,scanning electron microscope and tensile,impact properties test were carried out for the samples from different areas of the burst pipe.The results show that under the action of alternating load in the pipe,stress concentration occurs in the defect position with incomplete penetration,slag inclusion and porosity,cracks initiate and propagate,and eventuallyleads tofatiguefracture.