(1. 华南理工大学 国家金属材料近净成形工程技术研究中心，广州 510640；
2. 广东华艺卫浴实业有限公司，江门 529321)
摘 要: 通过添加Si和Al代替HPb59-1铅黄铜的Pb，采用锌含量法调控相组成，结合XRD、SEM和XPS等分析方法研究合金元素及其决定的相组成对无铅环保硅黄铜耐蚀性能的影响。结果表明：随着Zn含量增加，合金相组成由α+β、β转变到β+γ，基于脱锌层厚度可得这三类合金的抗脱锌能力由大到小依次为β、α+β、β+γ。在α+β和β+γ型黄铜腐蚀过程中，β相作为阳极优先被腐蚀，随后为α相和γ相。添加Si、Al、B和RE等元素后，所有合金的脱锌层厚度均在200 μm以下，其中Zn含量为46.2%的合金脱锌层厚度仅为92.4 μm，远优于HPb59-1铅黄铜的。无铅硅黄铜的脱锌腐蚀表层氧化膜主要由Cu2O、CuO、SiO2和Al2O3组成，Al和Si元素的添加提高了无铅硅黄铜的耐脱锌腐蚀能力。
关键字: 无铅硅黄铜；Zn含量；相组成；耐蚀性能
（1. National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, China;
2. Guangdong Huayi Plumbing Fittings Industry Co., Ltd., Jiangmen 529321, China）
Abstract:By adding Si and Al instead of Pb in HPb59-1 lead brass, the phase composition of lead-free environment- friendly silicon brass was controlled by zinc equivalent rule. The effects of alloying elements and phase composition on the corrosion resistance of the controlled alloys were analyzed by XRD, SEM and XPS methods. The results show that, with the increase of zinc equivalent, the phase composition of the controlled silicon brasses transforms from α+β and β into β+γ. Based on the thickness of dezincification layer, the anti-dezincification ability decreases successively as following of β, α+β, β+γ. During the corrosion process of α+β and β+γ brasses, the potential negative β phase is preferentially corroded as an anode, and then is α phase or γ phase. After adding Si, Al, B and RE, the thickness of the dezincification layer of all controlled alloys is below 200 μm. Especially, the corresponding thickness value for the alloy with the zinc equivalent of 46.2% is only 92.4 μm, which indicates that the corrosion resistance is improved significantly compared with HPb59-1 lead brass. The surface oxide film of the prepared silicon brass following dezincification corrosion is mainly composed of Cu2O, CuO, SiO2 and Al2O3, and additions of Al and Si elements improve the dezincification resistance of lead-free silicon brass.
Key words: lead-free silicon brass; zinc equivalent; phase composition; corrosion resistance
