带锈青铜文物材料在环境模拟介质中的腐蚀发展行为

目的研究3种带锈青铜及裸青铜文物材料在3种环境模拟液中的腐蚀发展行为。方法采用动电位扫描和SEM-EDS等方法研究试样的腐蚀特征和现象。结果在模拟大气环境介质中,电位在50~160 m V阳极极化范围内,与其他三种青铜材料相比,带CuCl锈青铜的阳极腐蚀电流密度最小;在模拟海水介质中,锈蚀青铜的腐蚀电流密度略大于裸青铜的;在模拟SO_2环境介质中,4种青铜试样的Rp值均大于大气环境介质中的。结论在模拟大气环境介质中,且阳极极化电位接近自腐蚀电位时,CuCl锈对青铜基体具有一定的保护性;在模拟海水环境介质中,带锈青铜的表面锈对基体没有保护作用;在模拟SO_2环境介质中,与在模拟大气环境介质中相比,SO_3~(2-)的引入会抑制青铜的腐蚀。表面形貌和能谱分析结果表明,裸青铜、CuCl锈青铜和混合锈青铜在模拟SO_2环境介质中,有点蚀现象发生,对粉状锈的生成有抑制作用。

Corrosion Development Behavior of Patinated Bronze Relics in the Environ-mental Simulation Media

The work aims to study the corrosion development behavior of patinated bronze in 3 kinds of environment simu-lated solution. Corrosion features and phenomena of the samples were studied by means of potentiodynamic scanning, SEM-EDS, etc. In simulated atmospheric environmental medium, potential fell within 50~160 mV, the range of anodic polariza-tion. Compared with other three bronze materials, the anode corrosion current density of bronzes covered with CuCl rust was the minimum; in simulated sea water environmental medium, the anode corrosion current density of patinated bronzes were all slightly greater than bare bronze; in simulated SO2 environmental medium, the Rp values of four bronze samples were all greater than that in atmospheric environment. In simulated atmospheric environmental medium, the CuCl patina was protective for bronze substrate at more negative potential; in simulated sea water environmental medium, patinated bronze had no protective effect on the substrate; in simulated SO2 environmental medium, the introduction of SO32-inhibited the corrosion of bronzes. The surface morphology and SEM-EDS analysis results show that, in the simulated SO2 environmental medium, pitting corro-sion is present in bare bronze, CuCl patinated bronze and mixed patinated bronze, thus inhibiting the formation of powdery rust.