Influence of Specimen Geometry and Strain Rate on Ductile-Brittle Transition Characterisation of Reactor Pressure Vessel Steels Using the Small Punch Technique
Influence of Specimen Geometry and Strain Rate on Ductile-Brittle Transition Characterisation of Reactor Pressure Vessel Steels Using the Small Punch Technique
复制标题
试样几何形状和应变率对采用小冲压技术的反应堆压力容器钢韧脆转变特征的影响
DOI：
10.1115/pvp2015-45373
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Adams J
中科院分区：
文献类型：
--
作者：
Adams J
小冲杆（SP）拉伸试验最初是为评估核安全壳的完整性而开发的，近年来随着《操作规范》和标准化提案的出台而复兴。对于核应用，所需的材料量极低，允许从准破坏性的勺状样品、监视样品甚至先前测试的夏比样品制造样品。材料的低体积还降低了健康和安全要求以及与测试活性材料相关的成本。通过评估断裂前所吸收的能量，可以用比单次夏比冲击试验所需的材料更少的材料建立完整的SP韧脆转变曲线，并对SA 508-3 NESC-1旋压筒体材料进行了小冲杆试验，以建立韧脆转变数据，并与传统夏比冲击试验技术所获得的数据进行比较。在现有规范的框架基础上，构建了多个SP延性-脆性转变曲线。采用新的几何形状和相关的加工技术，将缺口到SP试样的表面，以及相对较高的应变率的应用进行了研究。试验后的断口分析说明了应力升高特征和应变速率对小冲头断裂行为的影响。
The small punch (SP) tensile test, originally developed for assessing the integrity of nuclear containments, has seen a renaissance in recent years with the introduction of a Code of Practice and a standardisation proposal. For nuclear applications, the extremely low volumes of material that are required allows specimens to be manufactured from quasi-destructive scoop samples, surveillance specimens or even previously tested Charpy specimens. The low volume of material also alleviates the health and safety requirements and the cost associated with testing active materials. By assessing the energy absorbed before fracture, it is possible to build an entire SP ductile-brittle transition curve using less material than is required for a single Charpy test.Small punch testing has been performed on SA 508-3 NESC-1 spinning cylinder material to establish ductile-brittle transition data, for comparison to that obtained by conventional Charpy impact test techniques. Multiple SP ductile-brittle transition curves have been constructed, building upon the framework of the existing Code of Practice. Novel geometries and associated machining techniques employed to incorporate notches into the surface of the SP specimen, and also the application of relatively high strain rates have been investigated. Post-test fractography illustrates the influence of both stress raising features and strain rate on small punch fracture behaviour.