摘要
某化工企业一不锈钢管道的T型三通环焊缝内壁产生开裂,部分裂纹穿透管壁导致泄漏。通过试验分析表明,管道内143℃高温水注入常温EG水溶液会形成掺混区,对三通下游管壁产生交变的热应力;管道环焊缝在焊缝残余应力和交变热应力作用下产生热疲劳开裂;疲劳裂纹在介质压力、热应力共同作用下扩展,最终导致泄漏。进一步分析得出,通过改变焊缝位置、改变支管接入角度或添加布液器等方法可降低此处热疲劳开裂风险。
The inner wall of the girth weld on the T-tee of a stainless steel pipe in a chemical enterprise cracked,and some cracks penetrated the pipe wall and caused leakage.The experimental analysis shows that a mixing zone will be formed when high temperature water at 143℃is injected into normal temperature EG water solution in the pipeline,which will produce alternating thermal stress on the downstream inner wall of the T-tee.Thermal fatigue cracking occurs in the girth weld of the pipeline under the residual stress and the alternating thermal stress.Fatigue crack grows under the combined action of medium pressure and alternating thermal stress,which ultimately leads to leakage.Further analysis shows that the risk of thermal fatigue cracking can be reduced by changing the position of the weld,changing the access angle of branch pipe,or by adding a liquid distributor.
作者
钱锦烨
关凯书
Qian Jinye;Guan Kaishu(Key Laboratory of Pressure System and Safety(MOE),East China University of Science and Technology,Shanghai 200237,China)
出处
《压力容器》
北大核心
2019年第11期51-57,共7页
Pressure Vessel Technology
关键词
T型三通
环焊缝
交变热应力
热疲劳开裂
T-tee
girth weld
alternating thermal stress
thermal fatigue cracking
