金属和合金的腐蚀. 使用目视检查和硬度测量评估铜合金和灰铸铁的选择性腐蚀

[中文适用范围]： 本国际标准规定了现场检测和评估程序，以确定工业设施（包括核电厂）中敏感于选择性腐蚀的组件和结构的材料劣化（如材料损失）的影响。 该方法涉及现场目视检查和硬度测量，并辅以样品移除。这些程序包括：(a) 对敏感于选择性腐蚀的组件进行代表性采样，(b) 目视检查，和 (c) 硬度测试。为精确分析，建议进行额外的实验室测试。 该方法最适用于含锌量超过15%的灰铸铁和铜合金。扩展到其他合金需要验证的支持证据。 评估标准针对核电厂应用，在延长运行结束前的过去五年内定义进一步工程评估和行动的必要性，例如进一步采样、更高频率的检查以及组件维修或更换。 本规范不适用于无法通过光学或便携式硬度测试仪检测流体接触表面代表性采样的组件。此外，在非代表性组件选择（如HVAC或建筑服务应用）的情况下，本规范也不适用。对于非核电厂使用的组件，评估标准需由各方协商确定。仅硬度测试的评估标准不适用于Al-青铜、NAB和Cu-Ni结构完整性的评估。 [外文原描述]： ISO 17918:2015 specifies procedures of on-site detection and evaluation in order to determine the effects of material deterioration such as material loss from the components and structures that are sensitive to selective corrosion in industrial facilities, including nuclear power plants. The methodology involves visual inspection and hardness measurements in situ complemented by sample removal. These procedures include (a) representative sampling of components sensitive to selective corrosion, (b) the visual inspection, and (c) the hardness test, respectively. For an exact analysis, additional laboratory testing is recommended. The methodology is most applicable to grey cast iron and copper alloy with more than 15 % zinc. Extension to other alloys requires supportive evidence of validation. Assessment criteria orientated to the nuclear power plant application during the past five years before the end of extended operation define the necessity for further engineering evaluation and action like, for example, further sampling, higher frequency of inspection, and component repair or exchange. This specification is not applicable for components used where the representative sampling of surfaces in contact to the fluid is not detectable optically or detected with the portable hardness tester. Also, in case of non-representative component selection like in HVAC or building service application, this specification is not applicable. For components not used in nuclear power plant, the assessment criteria have to be agreed by the parties. Assessment criteria of hardness test alone is not applicable to the evaluation of structural integrity of Al-bronze, NAB, and Cu-Ni.