稀土元素添加对铁基非晶复合材料腐蚀行为影响

Corrosion performance of Fe-based amorphous composites with rare earth elements

摘要:

采用工业原料经包覆剂(CaO-Fe₂O₃-SiO₂)处理制备Fe-15Mn-5Si-14Cr-0.2C非晶复合材料棒状试样,添加稀土元素Ce、Dy及Ce+Dy,通过XRD研究稀土元素对微观组织的影响；采用电化学工作站三电极体系测试试样在1mol/L的HCl及1mol/L的NaOH中的腐蚀行为。结果表明：合金在添加稀土元素的组织依然为非晶复合材料(过冷奥氏体相CFe_15.1+ 铁素体相Fe-Cr),加入1%Ce的试样在HCl及NaOH的耐蚀性均为最佳,在HCl中自腐蚀电位为-0.16205V,自腐蚀电流密度为7.6999×10^₈A.cm^_-2,极化阻值达到9.5774×10^₈Ω.cm^₂,在NaOH自腐蚀电位和自腐蚀电流密度为-0.1839V,1.7453×10^_-8A.cm^_-2,极化阻值为7.1574×10^₈Ω.cm^₂,耐蚀性远优于AISI304,是潜力巨大的耐蚀材料。

关键词:非晶合金;稀土元素;微观组织;耐蚀性

Abstract:

The Fe-15Mn-5Si-14Cr-0.2C amorphous matrix composite rod sample was prepared from industrial raw materials by the coating agent (CaO-Fe₂O₃-SiO₂), and the rare earth elements Ce, Dy and Ce+Dy were added, and the rare earths were studied by XRD ;the influence of elements on the microstructure; the electrochemical workstation three-electrode system was used to test the corrosion behavior of the sample in 1mol/L HCl and 1mol/L NaOH. The results show that the alloy with rare earth elements is still amorphous composite material (undercooled austenite phase CFe_15.1 + ferrite phase Fe-Cr), and the sample with 1% Ce is resistant to corrosion in HCl and NaOH .The self-corrosion potential in HCl is -0.16205V, the self-corrosion current density is 7.699×108A?cm^_-2, and the polarization resistance reaches 9.5774×108Ω?cm^₂. In NaOH the self-corrosion potential and self-corrosion current density is -0.1839V, 1.7453×10^_-8A?cm^_-2, and the polarization resistance value is 7.1574×10^₈Ω?cm2. The corrosion resistance is much better than 304 stainless steel. It is a corrosion-resistant material with great potential.

Key words:Amorphous alloy; rare earth element; microstructure; corrosion resistance