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在石油化工行业或高压埋地钢质燃气管道通常会发生腐蚀。对碳钢而言,其腐蚀类型多为均匀腐蚀或点腐蚀。而发生点腐蚀的管道,其腐蚀凹坑又往往不是个别的,有时凹坑密度相当高,且分布在管线的不同部位上。因此,测量管线蚀坑的最大深度是件很复杂的事。金属腐蚀表面蚀坑数与坑深的关系如表1所示,蚀坑数最大值所对应的点是蚀坑的平均深度,如用该值来评估其破坏程度显然是不科学的。因为引起破坏事故的只是最深的腐蚀凹坑,而要在管线上实际测出蚀坑的最大值又往往具有很大的偶然性,而且测量的实际点数不可能包揽腐蚀坑的全部,不能保证在有限的测量点中包括其最深的腐蚀坑。为了求出每根
Corrosion usually occurs in the petrochemical industry or in high pressure buried steel gas pipelines. For carbon steel, the corrosion types are mostly uniform corrosion or pitting corrosion. Pitting corrosion occurs in the pipeline, the corrosion pits and often not individual, and sometimes the pit density is quite high, and distributed in different parts of the pipeline. Therefore, it is a complicated matter to measure the maximum depth of a pipeline pit. The relationship between the number of pits on the metal corrosion surface and the depth of the pits is shown in Table 1. The point corresponding to the maximum number of pits is the average depth of the pits. It is obviously unscientific to evaluate the degree of destruction by this value. Because only the deepest corrosion pits cause damage accidents, and to actually measure the maximum pits on the pipeline is often a lot of chance, and the measurement of the actual points can not swept all the corrosion pits, can not guarantee that in the limited The measurement points include the deepest corrosion pits. In order to find each root