稀土元素添加对铁基非晶复合材料腐蚀行为的影响

Effect of Rare Earth Elements Addition on Corrosion Behavior of Fe-based Amorphous Composites

采用工业级原料经包覆剂(CaO-Fe_(2)O_(3)-SiO2)处理制备了Fe-15Mn-5Si-14Cr-0.2C和添加稀土元素Ce、Dy及Ce+Dy的非晶复合材料棒状试样,用XRD和TEM研究不同稀土元素对复合材料微观组织的影响,用电化学工作站三电极体系分析试样在1 mol/L的HCl及1 mol/L的NaOH中的腐蚀行为。结果表明:合金在添加稀土元素后的组织仍为非晶复合材料,晶体相为过冷奥氏体相CFe15.1和铁素体相Fe-Cr。加入质量分数1%Ce的试样在HCl及NaOH中的耐蚀性均为最佳,在HCl中自腐蚀电位为–0.162 05 V,自腐蚀电流密度为7.6999×10^(-8) A·cm^(-2),极化阻值达到9.5774×10^(8)Ω·cm^(2);在NaOH中自腐蚀电位和自腐蚀电流密度分别为–0.1839 V,1.7453×10^(-8) A·cm^(-2),极化阻值为7.1574×10^(8)Ω·cm^(2)。耐蚀性远优于AISI304,是潜力巨大的耐蚀材料。

The Fe-15Mn-5Si-14Cr-0.2C amorphous composite rod sample added with and without rare earth elements of Ce, Dy and Ce+Dy were prepared using industrial purity raw materials treated by the coating agent(CaO-Fe_(2)O_(3)-SiO2). The effects of Ce, Dy and Ce+Dy rare earth elements addition on the microstructure were studied by XRD and TEM. The electrochemical workstation three-electrode system was used to test the corrosion behavior of the sample in 1 mol/L HCl and 1 mol/L NaOH. The results show that the microstructure of the alloys added with rare earth elements is amorphous composite matrix with the undercooled austenite phase CFe15.1 and the ferrite phase Fe-Cr. The corrosion resistance of the sample with 1 wt% Ce in HCl and NaOH is optimum. The self-corrosion potential in HCl is –0.162 05 V, the self-corrosion current density is 7.6999×10^(-8) A·cm^(-2), and the polarization resistance reaches 9.5774×10^(8) Ω·cm^(2). In NaOH, the self-corrosion potential and self-corrosion current density is –0.1839 V, 1.7453×10^(-8) A·cm^(-2), respectively, and the polarization resistance value is 7.1574×10^(8) Ω·cm^(2). The corrosion resistance is obviously better than that of 304 stainless steel. It is a corrosion-resistant material with great potential.