Study on the Stainless Steel with Photo Induced Self Healing Ability

不锈钢光致自愈能力的研究

基本信息

批准号：
06555211
负责人：
SHIBATA Toshio
金额：
$ 8.51万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

Photo electrochemical response has been applied as a poweful in-situ characterization technique for the passive film on the metals and alloys. However, the effect of the light exposure on the corrosion behavior has been open to discussion. In this study, Type304 stainless steel immersed in 3.5% NaCl was exposed with ultra-violet light to improve pitting corrosion resistance in the same media. uv light of 325 nm in wave-length generated by He-Cd laser was used as light source with output power of 35 mW and the exposure area of 6 mm in diameter. The pitting potential, which is an index for pitting corrosion resistance, was shifted for about 80 mV after uv light exposure during film formation period prior to pitting corrosion test. The improvement of pitting corrosion resistance depends on the light intensity. In the range of the light available in this study, a most suitable intensity was observed.The pitting corrosion induction period at a constant applied potential was also measured and analyzed with the birth and death stochastic probability process for various applied potentials to obtain the generation and repassivation rate of pitting corrosion. The generation rate, gamma, was lowered by a factor about 6 after exposure of uv light during passivation. On the other hand, the uv exposure during pitting corrosion generation period leads to almost no change on mu, the repassivation rate. The exposure during pitting corrosion generation affects only very small improvement on lambda and mu.The X-ray photo electron spectroscopy revealed that the chromium in the passive film, which is known to improve the corrosion resistant of stainless steels, is enriched after an exposure of uv light. Therefore the uv exposure was confirmed to improve the self healing ability of stainless steel, which is obtained by chromium enrichment in the film.

照片电化学响应已被用作金属和合金上的被动膜的能力原位表征技术。但是，光暴露对腐蚀行为的影响已经开放。在这项研究中，将浸入3.5％NaCl中的Type304不锈钢暴露于超紫外线，以改善同一介质中的耐矿化腐蚀性。 HE-CD激光器产生的波长325 nm的UV光用作光源，输出功率为35 MW，并且直径为6 mm的暴露面积。在蚀刻腐蚀试验前膜形成期间，紫外线暴露在紫外线曝光后，将蚀势是用于点蚀腐蚀性的指数。点腐蚀性的改善取决于光强度。在本研究中可用的光范围内，观察到最合适的强度。还测量了恒定施加电势下的点腐蚀诱导周期，并通过出生和死亡随机的概率过程进行分析，以获得各种应用的潜力，以获得腐蚀的生成和递增速度。在钝化过程中，紫外光暴露后，发电速率伽玛被降低了约6个因子。另一方面，在点腐蚀产生期间的紫外线暴露几乎不会改变MU，Repassivation速率。点蚀产生期间的暴露仅影响lambda和MU的改善。X射线照相电子光谱表明，被动膜中的铬在暴露于紫外光后富集，该铬在不锈钢的耐腐蚀性上富含。因此，确认紫外线暴露以提高不锈钢的自我修复能力，这是通过膜中的铬富集获得的。