Test data for low cycle fatigue - strain control on material INCONEL 617 at 700 Celsius

The Alloy 617 creep rupture data were determined for the high temperature reactor projects (the direct cycle helium turbine project, the nuclear process heat project and the district heating project) of the Federal Republic of Germany and the State of North Rhine Westphalia, the aim being to qualify the alloy for service at temperatures up to 950°C. Alloy 617 was the prime candidate alloy for construction of the He-He intermediate heat exchanger and hot gas ducting. Several batches and product forms (forged bar, rolled plate, pipes and tubes) of the alloy were investigated and special attention was given to the effects of the service environments (helium containing different impurity gases, such as hydrogen, water vapour, carbon monoxide and methane, all at microbar levels, and methane reforming gas mixture) on the properties. In the test machines, these test environments led to carburisation of test pieces. However, analysis of the data showed that the stress rupture data for tests in air, in impure helium and in methane reforming gas lay in the same scatter band at each temperature tested.

The creep rupture tests were carried out in single-specimen and multi-specimen test machines. In the single specimen machines the strain was continuously monitored and strain readings were taken once a day. In the multi-specimen test rigs, there were six strings, each with a different load. There were up to eight test pieces per string and strain measurements were made by interrupting the tests, cooling to room temperature, then measuring the length of each test piece using a travelling microscope. Test interruptions for strain measurements were generally every 1000 h. The tests were carried out according to the German Standard DIN 50118 (1982).

The data (secondary creep rate, time to 1% strain, time to rupture) were used for the formulation of draft nuclear design rules for the high temperature reactor systems, which are summarised in 'Proceedings of the Workshop on Structural Design Criteria for HTR', G Breitbach, F Schubert, H Nickel, Jül-Conf-71, April 1989, Berichte der Kernforschungsanlage Jülich GmbH, ISSN 0344-5798.

In addition to the creep rupture data, Alloy 617 tensile properties, low cycle fatigue and creep crack growth data are stored in MatDB.

Alloy 617蠕变断裂数据是为德意志联邦共和国及北莱茵-威斯特法伦州的高温反应堆项目（直接循环氦气轮机项目、核工艺热项目和区域供热项目）测定的，旨在使该合金具备在最高950°C温度下服役的资质。Alloy 617是氦-氦中间换热器和热气管道建造的首选候选合金。研究了该合金的多个批次及产品形态（锻棒、轧制板材、管材），并特别关注了服役环境（含氢、水蒸气、一氧化碳和甲烷等不同杂质气体的氦气，以及甲烷重整气混合物）对性能的影响。在试验机中，这些测试环境导致试样发生渗碳。然而，数据分析表明，在空气、不纯氦气和甲烷重整气中测试得到的应力断裂数据在各测试温度下均处于同一分散带内。

蠕变断裂试验在单试样和多试样试验机中进行。在单试样试验机中，应变被连续监测，且每日记录一次应变读数。在多试样试验装置中，设有6个加载串，每个加载串的载荷不同；每个加载串最多包含8个试样，应变测量通过中断试验、冷却至室温后使用移动显微镜测量每个试样的长度来完成。应变测量的试验中断通常每1000小时进行一次。试验依据德国标准DIN 50118（1982）开展。

这些数据（二次蠕变速率、1%应变时间、断裂时间）被用于高温反应堆系统核设计规则草案的制定，相关内容汇总于《高温反应堆结构设计准则研讨会论文集》（G Breitbach、F Schubert、H Nickel编著，Jül-Conf-71，1989年4月，于利希核研究中心报告，ISSN 0344-5798）。

除蠕变断裂数据外，Alloy 617的拉伸性能、低周疲劳和蠕变裂纹扩展数据均存储于MatDB中。