实海暴露黄铜脱锌腐蚀行为及抑制脱锌机理研究

采用金相－扫描电子显微镜和电子探讨Ｘ射线能谱成分分析方法研究了黄铅实海暴露脱锌腐蚀特征及抑制机理。通过对长期实海暴露试样的腐蚀产物和合金基体进行成分分析及形貌观察，研究表明加Ａｓ的Ｈ６８Ａ黄铜晶界优先发生脱锌腐蚀，而加Ｓｎ后，由于-了晶界，　大大提高了单相α黄铜(HSn70-1A)的耐蚀性能.而对双相HSn70-1A黄铜,添加Sn,可在一定程度上抑制脱锌,但并不足以阻止腐蚀沿β相之间的α相晶界的连通.

DEZINCIFICATION CORROSION BEHAVIOR AND ITS INHIBITING MECHANISM OF BRASS EXPOSED TO SEAWATER

In present paper, characteristic and mechanism of corrosion of brass exposed to seawater for several years, including alloys with single phase and afp double phase, have been investigated by means of metallograph, SEM, EDXA and so on. It was shown that se- vere corrosion with intergranular and dezincification characteristic occurred for the specimens of HSSAr which was single a-phase brass with As addition. For the brass of HSn70-1A, which was single-phase alloy with As and Sn additions, could exhibit much better corrosion resis- tance with Sn-rich corrosion product film. Sn element was much easier to enrich at grain boundaries. This would inhibit dezincification of the afp double phase brass to some extent. However, it was not enough for the Sn element addition in the brass HSn6*-1 with a+P double phase to resist dezincification corrosion getting through phase and grain boundaries of the brass. It was observed that diffusion of alloying elements at boundaries played an important role on the corrosion behavior of both a-phase and afp double-phase brass.