CO_2腐蚀的产物膜及膜中物质交换通道的形成

THE FORMATION OF PRODUCT SCALE AND MASS TRANSFER CHANNELS DURING CO_2 CORROSION

用SEM分析CO2 腐蚀过程中腐蚀产物膜及膜中物质交换通道的形成。在CO2 腐蚀过程中形成的腐蚀产物FeCO3 膜分为结构和成分各不相同的三层 ,且膜内有众多通道 ,造成腐蚀介质穿透膜进入金属表面腐蚀金属 宏观和微观通道形成的原因包括膜形成过程中的缺陷、膜在腐蚀介质中的溶解、应力造成的腐蚀产物膜的破裂等 ,正是由于膜中大量通道的存在造成材料严重的局部腐蚀。

Formation of corrosion product scale and mass transfer channels in the scale during CO 2 corrosion have been studied by means of SEM.Three layers of FeCO 3 scale have different composition and structure.Many channels are found inside the layers,which makes the corrosive medium reach the surface of the metal.The reasons for forming the channel include FeCO 3 itself unperfect,dissolution of the scale in the corrosive medium,cracking of the scale resulting from stress inside it,etc.All these result in the severe local corrosion of the metal.