Test data for low cycle fatigue - strain control on material INCONEL 617 at 750 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.

本数据集涵盖为德意志联邦共和国及北莱茵-威斯特伐利亚州的高温堆项目（直接循环氦气涡轮机项目、核工艺热项目及区域供热项目）所测定的617合金（Alloy 617）蠕变断裂数据，旨在验证该合金在最高950℃工况下的服役适用性。617合金是氦-氦中间热交换器与热气体导管的首选候选结构材料。研究覆盖了该合金的多批次及多种产品形态（锻棒、轧制板材、管材与管件），并重点关注服役环境对材料性能的影响，这些环境包括含微量杂质气体（氢、水蒸气、一氧化碳及甲烷，分压均处于微巴量级）的氦气，以及甲烷重整混合气。在试验设备中，这些试验环境会导致试样发生渗碳现象。但数据分析表明，在各测试温度下，空气、不纯氦气及甲烷重整气氛中的应力断裂数据均处于同一离散带内。

蠕变断裂试验采用单试样试验机与多试样试验机开展。单试样试验机中，应变被连续监测，且每日采集一次应变读数。多试样试验台共设6组加载串，每组加载串对应不同载荷，每串最多搭载8个试样；应变测量通过中断试验、冷却至室温后，使用读数显微镜测量每个试样的长度实现。用于应变测量的试验中断间隔通常为每1000小时一次。所有试验均按照德国标准DIN 50118（1982）执行。

本数据集包含的次生蠕变速率、1%应变对应时间及断裂时间数据，被用于制定高温堆系统的核设计规范草案，相关内容总结于《高温堆结构设计准则研讨会论文集》（G Breitbach、F Schubert、H Nickel 编，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，MatDB中还存储了617合金的拉伸性能、低周疲劳及蠕变裂纹扩展数据。