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采用真空感应熔炼与提拉法技术,经由选晶器制备出三种不同Ti和Ta含量的单晶镍基合金试样,通过动电位极化曲线和交流阻抗法测试了单晶镍基合金(0 0 1)面在3.5%NaCl+10.5%Na_2SO_4溶液中的电化学腐蚀性能。结果表明:单晶镍基合金中的Ti主要提高合金在氯化物和硫酸盐水溶液中的自腐蚀电位而Ta可以提高合金的钝化性能,使得合金的钝化区间变宽,至钝电位变负和维钝电流降低,同时含有Ti和Ta的合金具有最小的自腐蚀电流和自腐蚀速度;含Ti、Ta的三种镍基合金交流阻抗谱均表现出单一的容抗弧,电化学腐蚀受合金中组元与腐蚀介质的电化学反应控制,同时含有Ti和Ta的合金具有最大的电荷传递电阻和最小的自腐蚀速度。
Three kinds of single crystal nickel-base alloy samples with different contents of Ti and Ta were prepared by crystal-melting process using vacuum induction melting and pulling technique. The dynamic characteristics of single-crystal nickel-base alloy 0 0 1) surface in 3.5% NaCl + 10.5% Na_2SO_4 solution. The results show that the Ti in the single crystal Ni-base alloy mainly increases the self-corrosion potential of the alloy in the chloride and sulfate aqueous solution while the Ta can improve the passivation properties of the alloy, so the passivation range of the alloy becomes wider and the blunder potential becomes negative And the decrease of blunt current, while the alloys containing Ti and Ta have the smallest self-corrosion current and self-corrosion rate. The AC impedance spectra of the three Ni-based alloys containing Ti and Ta all show a single capacitive arc, and the electrochemical corrosion Alloy element and the corrosion medium electrochemical reaction control, while containing Ti and Ta alloy has the largest charge transfer resistance and the smallest self-corrosion rate.