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前言长期以来。用电镀镉来防护飞机结构钢曾是一种偏爱的方法。然而在某种工业及酸性环境下,例如当有SO_2存在时,镉并不显示出良好的性能。由于大量采用高强度铝及高强度钢,镐镀层还会出现其它一些问题:镀过镉的紧固件拧入高强度铝合金中,窝孔中会产生鱼鳞状剥蚀,而在高强度钢上镀镉会出现氢脆,最近还发现镉会引起对钛结构的固体金属脆性,由于镉的毒性和对环境的污染,因此就进一步地认为不宜采用镉。为了改进耐腐蚀性能,在六十年代末由美
Foreword For a long time. The use of cadmium plating to protect aircraft structural steel was a preferred method. However, cadmium does not show good performance in some industrial and acidic environments, for example when SO 2 is present. As a result of extensive use of high-strength aluminum and high-strength steel, pickaxe plating there will be some other problems: the cadmium plated fasteners screwed into the high strength aluminum alloy, nest holes will have fish scaly erosion, and in high-strength steel Hydrogen embrittlement occurs when cadmium is plated. Cadmium has also recently been found to cause brittleness of the solid metal to the titanium structure, which is further considered undesirable due to the toxicity of cadmium and environmental pollution. In order to improve the corrosion resistance, by the United States in the late sixties