【作者】 董燕；

【导师】 金有海； 孟庆元；

【作者基本信息】 中国石油大学 ， 机械工程， 2011， 硕士

【摘要】 氢脆现象是困扰着石油化工生产的一个重要问题,氢向钢材内部的渗入易使钢材变脆乃至失效,最终酿成重大的事故与灾难。近年来,围绕设备内部溶液介质对于材料氢脆敏感性的影响问题已有大量研究工作的开展,对大气环境下的氢脆现象却未引起足够的重视。而根据国家炼厂的布局,越来越多的沿海炼厂诞生,考虑到海洋大气本身属于材料发生氢致开裂的敏感环境,结合炼厂工业大气中的SO2等污染物,高温高湿、高盐分、干湿交替的大气环境都可能促进氢向钢材基体的渗透,为生产的稳定运行埋下安全隐患,因此有必要围绕炼厂设备用钢在海洋大气中的氢渗透及脆性行为展开研究。本文以炼厂常用的Q345R(16MnR)钢为研究对象,利用双面电解池技术和慢应变速率拉伸法,结合扫描电镜对断口形貌观察和腐蚀产物分析,研究模拟海洋大气下各环境因素对此类钢材氢渗透行为的规律,并考察进入钢材内部的氢对其力学性能的影响,实验结果表明:⑴在模拟海洋大气环境下,16MnR钢存在氢渗透现象,随着温度、湿度的升高,试样的氢渗透行为加剧,且温度和湿度之间对促进此类钢材的氢渗透行为存在协同效应;亚硫酸盐在试样表面的沉积进一步加速材料的氢渗透现象;干湿交替环境对试样的氢渗透行为也存在明显的加速作用;氢渗透量与腐蚀失重存在线性关系。⑵氢的进入提高了16MnR钢的应力腐蚀敏感性,使其断后延伸率明显降低,扫描电镜分析结果显示,在断口边缘处能够看到脆性断裂的迹象,断口形貌随暴露时间的延长由韧性向脆性断裂转变;高温、高湿、含硫或干湿循环交替的大气环境都会使材料的力学参数降低,其中干湿循环交替的大气环境对16MnR钢的力学性能影响最大。更多还原

【Abstract】 Hydrogen embrittlement is a major problem puzzling the petrochemical production. Hydrogen permeations to steel inside make steel embrittle and even lose effectiveness easily, finally leading to immense accidents or disasters. In the pastfew years, there have been many researches about the solution medium’s effect in apparatus to the material’s hydrogen embrittlement sensitivity, yet that in atmosphere does not cause enough attention. According to refineries layout, more and more coastal factories appear. The marine atmospheric conditions are the sensitive environment for hydrogen induced cracking, and there are a lot of pollutants in the refining industry air, for example SO2 gas. If the atmospheric environment is high temperature and humidity, or high salinity,or depositing of pollutants, it is more likely that the environment will enhance the hydrogen’s permeating into steels. Permeating of hydrogen will bring about security hidden trouble,so the researches of hydrogen permeation and embrittlement of fining equipment steels in marine atmospheric conditions are very necessary.Q345R(16MnR) steel which is used widely in refineries is studied in this article. Devanathan-Stachurski technology,the slow strain rate methods as well as the fracture morphology analysis by Scanning Electron Microscope(SEM) were used to study the laws of this steel in simulated marine atmosphere with various environmental factors,and explore the influence of mechanical performance caused by hydrogen permeation. The results obtained showed that:(1) In simulated marine atmosphere, 16MnR steel had hydrogen permeation phenomenon. As the temperature and humidity increased,the hydrogen permeation phenomenon of sample became to exacerbated. There were synergistic effects between temperature and humidity. The deposition of sulphite could accelerate the hydrogen permeation process. Wet-dry cycle was also showed to accelerate the hydrogen permeation phenomenon significantly. The corrosion weight loss experiment showed that there was clearly linear relationship between corrosion weight loss and the amount of hydrogen permeation.(2) Permeating of hydrogen enhaceds the stress corrosion cracking sensitivity of 16MnR steel,and reduces the percentage elongation after fracture.The analysis results from SEM showed that there were signs of brittle fracture at fracture side-intry cutting. The fracture morphology changed from ductile fracture to brittle fracture as the exposure time increased.The atmospheric environment with high temperature ,high humidity or sulfur or Wet-dry cycle could reduce the mechanical parameters of materials. The Wet-dry cycle of atmospheric environment showed major influence on 16MnR steel.更多还原