Research Of Hydrogen Permeation And Embrittlement Of 16MnR Steel In Inshore Refinery Atmospheric Environment

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.