含硫原油对16Mn管线钢顶部腐蚀行为的影响

Effects of Sulfur-Containing Crude Oil on Top-of-Line Corrosion Behavior of 16Mn Pipeline Steel

采用含硫原油腐蚀试验箱模拟输油管道顶部腐蚀环境,研究了16Mn管线钢在含硫原油中不同温度和不同时间条件下的顶部腐蚀行为。采用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)等分析手段观察16Mn管线钢的腐蚀形貌、分析其表面腐蚀产物膜的成分,同时结合失重法计算得到试样的腐蚀速率。结果表明:16Mn管线钢的腐蚀速率随含硫原油温度升高逐渐增大,当温度超过60℃时,腐蚀产物膜形成,腐蚀产物膜可以阻隔钢基体与腐蚀介质的直接接触,从而减缓腐蚀进程,腐蚀速率停止上升并出现缓慢下降的趋势;在相同的腐蚀温度下,初期腐蚀速率较快,随着腐蚀时间的延长,致密的腐蚀产物膜逐渐在16Mn管线钢表面形成,有利于抑制顶部腐蚀进程,使腐蚀速率逐渐减小。

The corrosion environment at the top of oil pipeline was simulated by a sulfur-containing crude oil corrosion test chamber,and the top-of-line corrosion behavior of 16 Mn pipeline steel was studied in the sulfur-containing crude oil under different conditions of temperature and time.Scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD)were used to observe the corrosion morphology of the 16 Mn pipeline steel and to analyze the composition of the corrosion product film on the steel surface.The corrosion rate of the 16 Mn pipeline steel sample was calculated by weight loss method.The results show that the corrosion rate of the 16 Mn pipeline steel increased with the increase of temperature of sulfur-containing crude oil.When the temperature was over 60 ℃,the corrosion product film formed,which can block the contact between steel base and corrosive medium and then slow down the corrosion process,so the corrosion rate stopped rising with a tendency of slow decline.At the same corrosion temperature,the initial corrosion rate was fast.As the corrosion time prolonged,a dense corrosion product film gradually formed on the surface of 16 Mn pipeline steel,which was beneficial to suppress the top-of-line corrosion process and gradually reduced the corrosion rate.