主蒸汽管道弯管蠕变损坏分析

Analyzing the Creep Damage of Elbow in Main Steam Pipe

弯管是火力发电厂主蒸汽管道系统中较易损坏的部件之一。为保证主蒸汽管道系统的安全运行，运用力学理论推导主蒸汽管道弯管应力表达式，利用应力一应变关系式求得蠕变变形表达式。通过对编变变形表达式分析可知主蒸汽管道弯管的周向变形最大，而且越靠近中心面的点变形越大，因而容易在这些部位开裂。

Elbow is one of parts in the system of main steam pipe which is easy to damage. To protectthe safety of main steam pipe,the formula of stress in elbow of main steam pipe is derivated with mechanical theory and ultilizing the formula 0f stress-strain gains the farmula of creep. according to theformula of creep,cyclic strain of elbow in main steam pipe is the largest, more closing center planemore strain,these locations in the elbow are easy to cleave.