空氣預熱器用鋼材在硫酸中的腐蝕與沖蝕

Corrosion and Erosion Properties in Sulfuric Acid Slurry for the Steel Used in Air Preheater

溫東成(D. C. Wen) ； 鄭德隆(D. L. Cheng)

《中華科技大學學報》 49期 (2011/10) Pp. 1-13

https://doi.org/10.7095/JCUST.201110.0001

摘要

本研究以新日本製鐵公司生產之MnCrCu鋼(S-TEN 2)為實驗材料，討論在PH值1~7硫酸溶液中的腐蝕與沖蝕特性，及兩者間的交互作用機制，進而評估鋼材耗損的主控模式。試片以動電位極化試驗測試腐蝕特性，再以自組的沖磨腐蝕試驗機作浸入沖蝕顆粒（125~273μm碳化矽砂）和硫酸溶液比例為1:4之水砂混合漿料中的沖磨試驗，並以SEM觀察沖磨破壞表面。結果顯示，S-TEN2耐硫酸鋼在硫酸溶液中會先形成保護膜隔離Fe與硫酸溶液的接觸以減緩材料的腐蝕，但在不同酸性環境的保護力也不同，在pH值6至3環境，晶界區域外的其他部位，保護膜還能穩定存在，在pH2與1環境，保護膜失去效用，腐蝕加速進行。因S-TEN2在不同酸性環境的腐蝕率不同，使其在硫酸漿料中的沖磨腐蝕主控機制也不同，pH值由6至3為腐蝕主控的加值效應，pH值2與1為腐蝕與沖蝕相互加乘的協同效應。

關鍵字

耐硫酸鋼 ； pH值 ； 沖蝕 ； 腐蝕

並列摘要

In this paper, a MnCrCu acid resistance steel (S-TEN 2) was selected as test material. The influence of pH value range from 7 to 1 of sulfuric acid slurries on the corrosion and erosion properties of the tested steel was investigated using a rotated slurry erosion-corrosion test unit and a potentiodynamic polarization tester. The synergistic effect between corrosion and erosion and the control mode for the material losses during erosion-corrosion were discussed.Experimental results show that the passive film was formed on the surface of the test steels, as they were immerged into the slurry, to reduce the corrosion of the material. However, the protection behavior of the film was different at various acid environments. In pH 6 to 3 slurries, the protect films were steady on the surface apart the grain boundary areas. While in pH 2 and 1 slurries, all the passive films were breakdown and the corrosion was increased. Due to the corrosion rate was depended on the acid environment. The control mode for the material losses during erosion-corrosion was different. In pH 6 to 3 slurries, the control mode was additive effect based on corrosion, while in pH 2 and 1 slurries the weight loss of material was attributed to the synergistic effect between corrosion and erosion.

並列關鍵字

Acid resistance steel ； pH value ； Erosion ； Corrosion