金属阳极涂层在化工大气环境中的腐蚀行为

Corrosion Behavior of Metallic Anode Coatings in Industrial Atmosphere

为了解化工大气环境对碳钢表面金属阳极涂层的腐蚀性,开展了热喷涂锌、铝、锌铝合金涂层以及热镀锌、渗锌钢在化工大气环境中的曝露腐蚀试验。通过试样的腐蚀形貌、腐蚀速率变化及电化学测试,考察了金属阳极涂层在石油炼化大气环境中的腐蚀行为。结果表明:化工大气环境腐蚀等级为C4级;喷铝层的腐蚀速率最低;渗锌层的耐蚀性优于热镀锌层。10μm厚热镀锌板耐腐蚀寿命约为4 a,40μm厚热镀锌和渗锌层寿命大于10 a,150μm的喷涂层耐蚀寿命大于30 a。

Thermal spray Zn,Al,Zn-Al alloy coating and hot dip galvanized steel as well as sherardizing steel were exposed in the industrial atmospheric environment.The corrosion behavior of those metal coatings in the industrial atmospheric environment was studied through the morphology observation,corrosion rate and electrochemical tests.Results showed that the corrosion category of industry atmosphere was C4 level.The corrosion rate of Al coating was the lowest and the corrosion resistance of sherardizing steel was superior to that of hot dip galvanized coating.Besides,the service life of the hot galvanized sheet with a thickness of 10 μm was about 4 a,and the hot dip galvanized steel and the sherardizing steel with a thickness of 40 μm could be used for more than 10 a.Furthermore,the service life of the thermal spray coating with a thickness of 150 μm was more than 30 a.