蠕变裂纹扩展是25年前作为断裂力学学科引入的。然而，它在工程结构中的应用仍然很少。在爱迪生电气研究所（EEI）的资助下，WRC的压力容器研究委员会（PVRC）启动了一个项目，以促进在电厂维护策略中实施蠕变裂纹扩展方法。该目标设想了在施工后缺陷评估规范中纳入公认的蠕变裂纹扩展方法。现在，API/ASME服务适用性标准中包含的方法已经达到了目标。该计划的一个重要内容是建立一个国际公认的调查人员网络，开展该项目的工作，并利用该小组报告最新信息，作为制定拟议做法的基础。 该小组对目前使用的主要蠕变裂纹扩展方法/参数进行了明确评估，确定了每种方法的优缺点，并考虑了适用于待涵盖电厂应用的问题。本WRC公告涵盖了伦敦帝国理工学院Kamran Nikbin教授及其同事评估的程序。这是一套详细说明方法、保存所用数据并全面解释参与者和其他人概念的方法之一。增量增长的计算结果汇总在FAD图上。如果FAD上预测裂纹扩展到使用时间的点位于FAD失效轮廓之上或之外，则部件的寿命仅限于与此类使用相对应的时间。 如果此时间小于当前运行时间，则应修理或报废部件。

Creep crack growth was introduced over 25 years ago as a fracture mechanics discipline. However, its application to engineering structures remains rare.With funding provided by the Edison Electric Institute (EEI), WRC's Pressure Vessel Research Council (PVRC) initiated a program to facilitate implementation of creep crack growth methods in electric power plant maintenance strategies. The objective envisioned required incorporation of an accepted creep crack growth methodology in a post-construction flaw evaluation Codes. The goal has now been reached with the inclusion of methods in an API/ASME Fitness-for-Service Standard. An important element of the plan was to establish a network of internationally recognized investigators to work on the project and to use that group to report state of the art information as the basis for developing the proposed practice.The group provided a definitive evaluation of currently used major creep crack growth methods/parameters, identifying the strengths and weaknesses of each considering issues appropriate for use in the power plant applications to be covered. This WRC Bulletin covers the procedures evaluated by Prof. Kamran Nikbin and his colleagues at Imperial College in London. It is one of a set prepared to detail the methods, preserve the data used and comprehensively explain the concepts of the participants and others.The results of calculations of incremental growth are assembled on a FAD diagram. If a point on the FAD predicted for crack growth to a service time lies on or outside the FAD failure contour, then the life of the component is limited to the time corresponding to such service. If this time is less than the current operating time, the component should be repaired or retired.