Test data for uniaxial creep on material INCONEL 617 at 950 Celsius and a stress of 20 MPa (repeat test)

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.

617合金（Alloy 617）蠕变断裂数据的测试，是为德意志联邦共和国及北莱茵-威斯特伐利亚州的高温反应堆项目（直接循环氦气轮机项目、核工艺供热项目与区域供热项目）开展的，旨在验证该合金可在最高950℃的工况下服役。617合金是氦-氦中间热交换器与热气体导管系统建造的首选候选合金。研究覆盖了该合金的多个批次及多种制品形态（锻棒、轧制板材、管材与管件），重点考察了服役环境对材料性能的影响：包括含不同杂质气体（氢气、水蒸气、一氧化碳、甲烷，分压均为微巴级别）的氦气，以及甲烷重整混合气。在测试设备中，这类服役环境会引发试样的渗碳现象。但数据分析显示，在各测试温度下，空气、不纯氦气及甲烷重整气环境中的应力断裂数据均处于同一离散带内。

蠕变断裂测试采用单试样与多试样测试机开展。单试样测试机中，应变被连续监测，且每日采集一次应变数据。多试样测试台包含六组加载通道，每组加载不同载荷；每组最多可放置8个试样，应变测量需通过中断测试、冷却至室温后，使用读数显微镜测量每个试样的长度来完成。应变测量的测试中断周期通常为每1000小时一次。本次测试按照德意志联邦共和国标准DIN 50118（1982版）执行。

本次测试获取的数据（二次蠕变速率、产生1%应变的时间、断裂时间）被用于制定高温反应堆系统的核设计规范草案，相关内容汇总于《高温气冷堆结构设计准则研讨会论文集》（G Breitbach、F Schubert、H Nickel 著，会议编号Jül-Conf-71，1989年4月，于利希核研究中心有限公司报告，ISSN 0344-5798）。

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