火电厂耐热钢承压部件的蠕变损伤研究

A Study of the Creep-related Damage of Heat-resistant Steel Pressure Parts of a Thermal Power Plant

针对火电厂中蒸汽管道与汽包一类承压部件常用耐热钢材 ,在经历长时间高温高压作用后 ,处于蠕应变Ⅲ阶段过程时 ,发生非线性局部化 (大变形 )蠕变损伤问题 ,给出损伤本构描述 ,提出非线性局部化蠕变损伤本构模型及其数值变分原理与有限元离散化形式 ,从而形成另一种弹塑性蠕变损伤理论与数值变分新方法。

Heat-resistant steel materials are often used for the pressure parts and components of a thermal power plant, such as steam pipelines. After being subjected to high-temperatures and high-pressures lasting for a long time and with the eventual initiation of creep-strain stage III process there will emerge the problem of nonlinear localized (large deformation) creep damage. With reference to the latter the authors have given a damage constitutive description and presented a non-linear localized creep-damage constitutive model along with its numerical variation theory and finite-element discretization form. This has led to the formation of another kind of elastic-plastic creep-damage theory and a new numerical variation method.