1. Several NDT methods are available for sizing defects. The accuracy of US/TOFD basically meets the demands for life assessment. For crack growth assessment, a bigger safety margin for life time should be considered 2. Time-dependent fracture mechanics concepts are well developed, several standards, such as the R5 report and PD 6539:1991 are available to guide the life time assessment. 3. Material data for crack growth analysis in base metal are available. However, creep data for different weld HAZ are practically unavailable 4. Many engineering practices on life time assessment have been carried out in last decade. Life time assessment is applicable to components in electricity power plants. However, as the scatter in prediction is still big, a lot of work should be done to improve the accuracy. 5. At the high temperature region, the FFP approach is not included in the Dutch standard yet. However, the Dutch authorized body will accept this approach on a case by case basis.
展开▼
机译：1.有几种NDT方法可用于确定缺陷的大小。 US / TOFD的准确性基本上可以满足寿命评估的要求。对于裂纹扩展评估，应考虑更大的使用寿命安全裕度2。随时间变化的断裂力学概念已经得到很好的发展，一些标准（例如R5报告和PD 6539：1991）可用于指导使用寿命评估。 3.提供了用于贱金属裂纹扩展分析的材料数据。但是，实际上无法获得不同焊缝热影响区的蠕变数据。4.在过去十年中，进行了许多有关寿命评估的工程实践。寿命评估适用于发电厂的组件。但是，由于预测中的分散性仍然很大，因此需要做很多工作来提高准确性。 5.在高温地区，FFP方法尚未包括在荷兰标准中。但是，荷兰授权机构将视情况接受此方法。
展开▼
