...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Corrosion: The Journal of Science and Engineering >Modeling of Hydrogen Sulfide Corrosion by Coupling of Phase and Polarization Behavior
【24h】

Modeling of Hydrogen Sulfide Corrosion by Coupling of Phase and Polarization Behavior

机译：Modeling of Hydrogen Sulfide Corrosion by Coupling of Phase and Polarization Behavior

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相关主题

摘要

From an experimental evaluation of oil and gas field materials, a synergy between the formation of dark sulfide layers and hydrogen-supported sulfide stress cracking is frequently reported in the literature. The present work describes a first approach to a deterministic hydrogen sulfide (H_2S) corrosion model for the calculation of precipitation of pyrite (FeS), together with respective changes of pH at the anodic sites of the assumed corrosion system for pure Fe. The model is based on coupling the calculated anodic polarization curves to the precipitated equilibrium masses of magnetite (Fe_2O) and FeS_2, which in a "closed loop" time stepwise procedure are calculated from the solute concentrations. The results show that as a consequence of FeS_2 precipitation the local pH at the anodic site is reduced together with the changes of total concentrations of HS~-, Fe~++, and H~+ in the assumed diffusion layer. Also, the respective changes in corrosion currents and potentials are demonstrated. With increasing bulk pH and total pressures the acidification times from the start of the process to a local pH of 2.5 (t_(pH25)) increase while the respective mean corrosion currents are reduced. At higher pH levels, increasing H_2S contents lead to significant reductions in acidification times as well as corrosion currents. This effect is, however, smaller at lower total pressures. The calculated pH reductions follow a similar course of experimentally measured pH levels during precipitation of iron sulfides in a 0.5 bar H_2S-5 g/L sodium sulfate (Na_2SO) solution at galvanostatic loading with 0.8 mA/cm~2 in a closed cell As a summarizing result, an example ofapH-vol percent H2S domain diagram for constant total pressures, pH reduction time is established and discussed with respect to effects of anodically accumulated hydrogen on cracking processes.

著录项

获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号