碳鋼與耐候鋼20年大氣曝露研究

本研究是探討碳鋼與耐候鋼分別在中鋼公司及中山大學20年之大氣腐蝕行為。研究方法是實際曝露試驗，並以XRD與SEM/EDS進行腐蝕生成物分析。結果顯示鋼材經長期大氣曝露後，下表面腐蝕量比上表面多，但平均腐蝕失重C隨曝露時間t之關係滿足C=At^B，A、B為常數。其中，耐候鋼不僅A值比碳鋼小，B值也比碳鋼小，顯示耐候鋼耐候性較為優異。另外，耐候鋼增加Cr或Si或P含量可提升耐候性，但增加Mn含量反而會降低其耐候性。無論曝露前是拋光料或噴砂料，不同表面狀態經長期大氣曝露後，影響已甚微。同時，無論何種鋼料，在中山的腐蝕失重比在中鋼大，顯示氯離子的影響扮演關鍵角色。

關鍵字

耐候鋼；大氣腐蝕；耐候性；銹層

並列摘要

This study is to investigate the twenty-year atmospheric corrosion behaviors of a carbon steel and a weathering steel in China Steel Corporation and in National Sun Yat-Sen University. The experimental methods included actual exposure tests and analyses of corrosion products by XRD and SEM/EDS. Results revealed that after a long-term exposure, the extent of corrosion on the lower surface of steel was larger than that on the upper surface. The average weight loss (C) versus exposure time (t) can be correlated by the law C = At^B where A and B are constants. The weathering steel has lower A and B values than that of the carbon steel, indicating having better corrosion resistance. An increase in the amount of Cr, Si, or P in the weathering steel improved the corrosion resistance, while an increase in the amount of Mn lowered the corrosion resistance. The difference in weight loss between blasted steel and polished steel after long-term exposure is insignificant. The corrosion of the steels tested in Sun Yat-Sen University was more severe than that in China Steel Corporation, indicating that chloride in the atmosphere played an important role in corrosion.

並列關鍵字

Weathering Steel ； Atmospheric Corrosion ； Weathering Resistance ； Oxide Scale

主題瀏覽