环烷酸与有机硫对Cr5Mo钢高温腐蚀的交互作用研究  

HIGH TEMPERATURE INTERACTIVE CORROSION OF NAPHTHENIC ACID AND ORGANIC SULPHIDE ON Cr5Mo STEEL IN SYNTHETIC REFINING MIXTURE

作　　者：董泽华[1] 何金杯[1] 郭兴蓬[1] 张耀享 汉继成 

机构地区：[1]华中科技大学化学与化工学院,武汉430074 [2]中国石油兰州石化研究院,兰州111003

出　　处：《中国腐蚀与防护学报》2011年第3期219-224,共6页Journal of Chinese Society For Corrosion and Protection

基　　金：中国石油天然气总公司兰州石化项目(20090411)资助

摘　　要：以环烷酸、十二硫醇及白油组成的合成油模拟含酸含硫原油,采用旋转高压釜动态失重实验和微观分析手段,研究280℃下不同硫含量和环烷酸对Cr5Mo低合金钢腐蚀行为的交互影响。研究表明,当油中硫醇(以硫计算)含量<2mass%时,硫化物含量上升会迅速增加环烷酸的腐蚀性;而当油中硫含量>3mass%后,由于保护性Fe_7S_8/Cr_5S_8膜的形成,其腐蚀加速性又显著降低;高酸值下(原油酸值(KOH)>15mg/g),硫醇反而会抑制环烷酸腐蚀,酸值越高,硫醇对环烷酸腐蚀的抑制作用越强。研究还发现,二甲基亚砜含氧硫化物比硫醇对环烷酸腐蚀具有更强烈的抑制作用。Naphthenic acid corrosion （NAC）, sulfur corrosion （SC） and their interaction on Cr5Mo carbon steel were studied by mass loss test using a spinning coupon inside a heated autoclave at 280 ℃. The test mixture with different level of sulfur content and total acid number were prepared by pure naphthenic acid, lauryl mercaptan and low sulfur white oil. It was found that the increasing sulfur content can accelerate the NAC dramatically when the sulfur content lower than 2.0 mass%. However, the boost effect of mercaptan to NAC decreased quickly when the sulfur content is higher than 3.0 mass%, which could be attributed to the formation of protective FeTS8/Cr5S8 layer confirmed by scanning electron microscope （SEM）, energy dispersive X-ray （EDX） analysis and X-ray diffraction （XRD） analysis. Surprisingly, high content of lauryl mercaptan could even inhibit the NAC in case of higher TAN （〉15.0 mg/g KOH）, and the increasing content of TAN could enhance the inhibition of mercaptan on NAC. In contrast, the dimethyl sulfoxide （DMSO） exhibits stronger inhibition ability than mercaptan in case of high TAN in the test mixture.

关 键 词：环烷酸 有机硫 Cr5Mo钢 高温腐蚀 交互作用 

分 类 号：TG174.4[金属学及工艺—金属表面处理]