晶化行为对Fe基块体非晶合金腐蚀性能的影响

Effect of Crystalline Behavior on Corrosion Resistance of Fe-based Bulk Amorphous Alloy

采用电化学极化曲线和交流阻抗技术研究了Fe41Co7Cr15Mo14C15B6Y2非晶及其非晶/纳米晶合金在1.5 molHCl溶液中的腐蚀行为。利用XRD、DSC和SEM对非晶及其非晶/纳米晶合金的相组成、晶化过程及腐蚀形貌进行了分析。结果表明,Fe41Co7Cr15Mo14C15B6Y2非晶合金具有最佳的耐蚀性,虽然部分晶化的该非晶合金抗腐蚀性有所降低并具有差异性,但是自腐蚀电流密度以及钝化膜电阻依然与其非晶试样的数据在同一个数量级,说明其抗腐蚀性能下降并不十分明显。

Amorphous alloys Fe41Co7Cr15Mo14C1586Y2 were prepared by vacuum arc melting method and nano-crystalline Fe41Co7Cr15Mo14C15B6Y2 alloys were obtained by different annealing technique. The corrosion resistance of the alloys compared with its counterpart amorphous alloys in 1.5 mol HC1 solution were carried out by the potentiodynamic polarization method and the electrochemical impedance spectroscopy （EIS） technique respectively. The crystallization processes of the samples were identified by X-ray diffraction and differential scanning calorimeter. The morphologies of the samples after potentiodynamic polarization were observed by SEM. The results show that amorphous alloy has a higher corrosion resistance than that of the counterpart nano-crystalline alloys, but the self corrosion current density and passivation coating resistance of nano-crystalline alloys is the same order of magnitude as amorphous alloy, which mean that the decline rate of corrosion resistance of nano-crystalline alloys is not very obvious.