摘要
某150 MW塔式光热电站的熔盐管道发生开裂泄漏,通过宏观形貌观察、化学成分分析、拉伸性能试验、冲击性能试验、维氏硬度试验、金相分析、断口形貌分析、微区成分等方法分析了管道的开裂原因.分析结果表明:熔盐管道的开裂属于热疲劳开裂,起源于角焊缝根部的管道外壁熔合区,引起管道开裂的主要原因是管道介质温度变化过程中护板与管道间产生的交变热应力.
Abstract
The molten salt pipeline of a 150 MW tower photothermal power plant was cracked and leaked.The cracking cause of the pipeline was analyzed by means of macroscopic morphology observa-tion,chemical composition analysis,tensile property test,impact property test,Vickers hardness test,metallographic analysis,fracture morphology analysis,micro-area composition and other methods.The results show that the failure mode of molten salt pipeline belongs to thermal fatigue cracking,which origi-nates from the fusion zone of the outer wall of the pipeline at the root of the fillet weld.The main reason for pipeline cracking is the alternating thermal stress generated between the protective plate and the pipe-line during the temperature change of the pipeline medium.
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