Effect of Temperature and H2S Concentration on Corrosion of X52 Pipeline Steel in Acidic Solutions
作者单位：State Key Laboratory of Corrosion and Protection Institute of Metal Research Chinese Academy of Sciences
会议名称：《中国材料大会2012》
会议日期：2012年
学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）]
基 金：financial support of this study from Natural Science Foundation 51025104
关 键 词：H2S corrosion High H2S concentration Corrosion products.
摘 要：The corrosion behavior of X52 pipeline steel in H2S solutions was investigated through immersion corrosion test which was carried out in a high temperature and high pressure autoclave at different temperatures and H2S concentrations. General corrosion rates were calculated based on the weight loss of samples. The morphology and the chemical composition of the corrosion products were obtained by Scanning Electron Microscopy （SEM） and Energy Dispersive Spectroscopy （EDS）. The crystal structure of corrosion products was analyzed by X-Ray diffraction patterns （XRD）. The corrosion products consisted mainly of the sulfide compounds （mackinawite, cubic ferrous sulfide, troilite and pyrrhotite）. The corrosion products included two layers: the inner iron-rich layer and the outer sulfur-rich layer. Under H2S concentrations of 27g/L, the corrosion rate increased with the increase of temperature up to 90 ℃and then decreased at 120 ℃, finaly increased again. The corrosion rate first increased with H2S concentrations then decreased at 120 ℃. The structure and stability of the corrosion products due to different corrosion mechanism had a major impact on the corrosion rate. The corrosion resistance of the corrosion products increased as follows: mackinawite cubic ferrous sulfide troilite pyrrhotite.