金属和其他无机覆盖物 钢中可扩散氢的电化学测量

[中文适用范围]： 本国际标准描述了一种使用电子氢检测仪测量裸钢或镀层去除后镀钢中相对扩散氢浓度的方法。 假设氢均匀分布在整个零件中。 该方法不测量实际的氢气浓度。 然而，相对于时间测量的氧化电流密度提供了相对氢浓度的有用指示，因此，测量结果可用于比较目的。 该方法可用作质量控制程序，因为它确实提供了测量电镀前和/或电镀后热处理的有效性或监测电镀期间或由于腐蚀引起的氢吸收的快速方法。 值得注意的是，特定测试中没有失败并不能证实氢脆已完全消除，因为没有一种测试方法可以提供评估氢降解程度所需的所有数据。 对于未电镀的零件，该方法是非破坏性的；然而，对于电镀零件，必须事先去除涂层。 采用经证明不会损坏钢材或引入氢气的方法进行测量。 本试验方法仅限于： ——碳钢和合金钢，不包括奥氏体不锈钢（见注 1）； ——可以附着电池的扁平样品（见注 2）； ——室温（25℃±1℃）下测量。 注 1：如果该方法用于奥氏体不锈钢和其他面心立方 (FCC) 合金，则由于涉及不同的动力学，必须确定测量时间和结果解释。 注 2：对于轻微弯曲的表面，必须定义一个可再现的区域。 面积计算将与本国际标准中描述的不同。 注 3：该方法可以应用于小零件，但是，这需要对技术、程序和结果解释进行一些修改。 [外文原描述]： This International Standard describes a method that uses an electronic hydrogen detection instrument for measuring relative, diffusible hydrogen concentrations in bare steels or in plated steels after the coating has been removed. It is assumed that the hydrogen is uniformly distributed throughout a part. The method does not measure actual hydrogen concentration. However, oxidation current densities measured against time provide a useful indication of relative hydrogen concentrations and, therefore, the measurements can be used for comparison purposes. The method may be used as a quality control procedure as it does provide a quick means of measuring the effectiveness of pre- and/or post-plating heat treatments or of monitoring hydrogen uptake during plating or due to corrosion. It is important to note that the absence of failure in a particular test does not provide confirmation of complete elimination of hydrogen embrittlement because no one test method can provide all the data necessary to evaluate the degree of hydrogen degradation. For unplated parts the method is non-destructive; however, for plated parts the coating has to be removed prior to measurement by a means proven not to damage the steel or to introduce hydrogen. This test method is limited to: — carbon and alloy steels, excluding austenitic stainless steels (see note 1); — flat specimens to which the cell can be attached (see note 2); — measurements at room temperature ( ). NOTE 1 If this method is used for austenitic stainless steels and other face centred cubic (FCC) alloys, measurement times and interpretation of results will have to be determined because of the different kinetics involved. NOTE 2 For slightly curved surfaces it is essential to define an area that is reproducible. The area calculation will be different from that described in this International Standard. NOTE 3 The method can be applied to small parts, however, this necessitates some modification of the technique, procedure and interpretation of results.