ABSTRACT The paper presents a procedure for assessing the condition of the current structure of boiler tubes. First, a modified version of the Garofalo equation is proposed to model the strain-and-stress state under creep conditions in Super304H steel. In parallel with the creep model development, the microstructure is examined using SEM and TEM techniques. The Super 304H steel structure is tested for a new material and for the superheater material after 100,000 h of operation. According to the presented description of the tested steel degradation, it is possible to operate the material for another 100,000 h if the design conditions are met. The results show that the conventional approach based on European standards does not exclude the superheater safe operation. However, a more detailed analysis, taking account of additional loads from the pipeline and using the proposed creep equation, proves that the conditions for the superheater safety are not satisfied.

中文翻译：

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蠕变条件下动力锅炉过热器应变应力状态分析

摘要 本文提出了一种评估锅炉管当前结构状况的程序。首先，提出了 Garofalo 方程的修改版本来模拟 Super304H 钢在蠕变条件下的应变和应力状态。在开发蠕变模型的同时，使用 SEM 和 TEM 技术检查微观结构。Super 304H 钢结构在运行 100,000 小时后接受了新材料和过热器材料的测试。根据所测试的钢材退化的描述，如果满足设计条件，则可以将材料再运行 100,000 小时。结果表明，基于欧洲标准的常规方法并不排除过热器的安全运行。然而，更详细的分析，