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摘要：本课题为不锈钢晶间腐蚀研究，主要研究不锈钢在不同情况下的腐蚀性能。本文主要讨论：从不锈钢的腐蚀浸泡实验，采用GB/T4334-2008-E（我国国家标准）、ASTM A262-02a(2002) E（美国标准）和RCC-M1310（法国标准）这三种标准来测试304型不锈钢的耐晶间腐蚀性能，从宏观的弯曲形貌、金相照片以及SEM扫描照片考察材料的耐晶间腐蚀性能。对于304 的材料在ASTM、RCC-M、GB/T的标准下进行敏化和腐蚀实验，可以发现RCC-M标准下，弯曲的样品出现了褶皱和微裂纹，金相和SEM扫描图像均出现了较为明显的晶间腐蚀形貌，所以RCC-M标准在此304样品下作为敏化和腐蚀标准更容易出现晶间腐蚀倾向。34709
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不锈钢由于其优良的抗均匀腐蚀性能，现在已经在全世界的汽车工业、水工业、建筑业、家电业、环保工业、工业设施等很多的领域都得到了非常广泛的应用。可是如果在450-900℃的腐蚀性介质中使用的话，不锈钢就非常容易发生晶间腐蚀，甚至会导致应力腐蚀开裂。这是不锈钢因为碳在较低的温度下会以富铬碳化物的形式析出，这就会让晶界和邻近区域的铬含量下降，从而就形成了贫铬区，所以发生晶间腐蚀。这个贫铬区非常容易被腐蚀，导致晶间腐蚀或者应力腐蚀开裂。所以这就需要对不锈钢材料应用之前通过实验方法检测是否会产生晶间腐蚀，例如，采用硫酸-硫酸铜-铜屑法、沸腾硝酸法、硝酸-氟化物法、硫酸-硫酸铁法。本论文采取硫酸-硫酸铜-铜屑法为主要方法作为腐蚀实验，并且按照三个不同的晶间腐蚀试验标准为： GB/T4334-2008-E（我国国家标准）、ASTM A262-02a(2002) E（美国标准）和RCC-M 1310（法国标准）分别进行敏化和腐蚀，从不同的标准角度入手来检测材料的耐晶间腐蚀性能。研究了原材料、敏化未腐蚀、敏化腐蚀、未敏化直接腐蚀的情况下，试样的弯曲宏观形貌、金相组织、SEM扫描图像，从宏观形貌和微观形貌方面来观察试样产生晶间腐蚀的情况。
毕业论文关键词：304不锈钢，晶间腐蚀，铬含量
Corrosion of stainless steel
The issue is to discuss ntergranular corrosion of stainless steel,Mainly in order to study the stainless steel indifferent situations corrosion.This article focuses on：For the stainless steel corrosion immersion experiments, GB/T4334-2008-E (China's national standard), ASTM A262-02a (2002) E (U.S. standard) and the RCC-M1310 (French standards) these three criteria are adopted to test four different types of 304 stainless steel to intergranular corrosion resistance, from a macro morphology of a bending sample, SEM photomicrographs and scanning photos.304 stainless steel for materials in ASTM, RCC-M, GB / T standard under sensitized and corrosion experiments can be found RCC-M standard, curved samples appeared folds and microcracks, optical and SEM were scanned image appears more obvious intergranular corrosion morphology, so RCC-M standard in this 304 sample as a sensitizer and more prone to corrosion standards tendency to intergranular corrosion.
Stainless steel is widely used in many areas such as the automobile industry, the water industry, construction, household appliances industry, environmental industry and industrial facilities due to its excellent resistance to uniform corrosion performance. However, if used in the corrosive medium at 450-900℃, the stainless steel is easily found the occurrence of intergranular corrosion, and even the stress corrosion cracking. Since the carbon steel separate out in the form of precipitation of chromium-rich carbides at a lower temperature, which makes the chromium content near the grain boundary region and down to form a chromium depleted zone, the intergranular corrosion occurs. The chromium depleted zone is very susceptible to corrosion, resulting in intergranular corrosion or stress corrosion cracking. Before application, stainless steel needs to be detected experimentally whether intergranular corrosion will occur, for example, sulfuric acid-copper-copper scrap method, boiling nitric acid, nitric acid-fluoride method and sulfuric acid-ferric sulfate method. In this paper, acid-copper-copper scrap is taken as the main method of corrosion test, and following are three different intergranular corrosion test standards: GB/T4334-2008-E (China's national standard), ASTM A262-02a (2002 ) E (U.S. standard) and the RCC-M 1310 (French standards). They are sensitized and corrosion from a different point of view to detect the material standard of resistance to intergranular corrosion. Materials are pided into four conditions, such as original one, sensitization but not corrosion, sensitization corrosion, not sensitized but corrosion. macro-morphology of the bending sample, microstructure, SEM scanning images from the macro aspects of the morphology and microstructure are used to observe trial kind of produce cases intergranular corrosion. Though traditional methods can be used to detect intergranular corrosion of stainless steel, there are some undesirable places. The role of the sample is damaged, or it takes a long time, or the degree of intergranular corrosion can not be quantitatively detected. So a rapid, non-destructive detection method is needed.