材料期刊网

<正> 近来发现在 HSn70-1A 黄铜中加痕量硼制成的冷凝管,在热电厂装机运行其耐蚀性能有明显的改善。实验室初步研究未发现加极微量硼会提高黄铜基材的耐蚀能力,因而把现场试验结果归因于退火后形成表面膜的贡献。Toivanen 用俄歇能谱及正电子湮没研究了硼在黄铜腐蚀过程中的作用,认为硼能占据脱锌后产生的空位,阻止锌原子迁移,从而有效地减小脱锌速度及脱锌层厚度起伏。本工作通过在含砷及不含砷的70/30黄铜中加不同量的硼,探索硼对其耐蚀性能影响、寻找最佳含量,以期发展出比现行加砷黄铜更耐蚀的合金。

A new brass condenser tube containing trace boron ,which has been used in heat power station for more than four years,shows higher cor- rosion resistance than that of normal brass tubes.Therefore the anti- corrosion properties of 70/30 brass containing different amounts of boron with or without arsenic were investigated systematically.The measur- ements of corrosion weight loss and dezincification coefficient showed that the boron improved the corrosion resistance especially to dezinc- ification ,whether the brass contained arsenic or not.The optimum amount of boron in brass is 0.03～0.05wt.% in the absence of arsenic and 0.02～0.03wt.% in the presence of arsenic. An improved material with better corrosion resistance could possibly be developed by adding trace boron to brass with a certain amount of arsenic content.The improvement of corrosion resistance of this new kind of brass can be explained by the obstruction of boron to the diff- usion path of zinc for dezincification.