温度对J55钢铬铝合金化后电化学阻抗谱的影响

Effect of Temperature on Electrochemical Impendence Spectrum of Chromium-AluminumAlloyed J55 Steel

为了提高油气开采用材J55钢的耐蚀性,对其进行铬铝合金化。用电化学法研究了其在3.5%NaCl溶液中的腐蚀行为,考察了温度对其电化学阻抗谱的影响。结果表明:铬铝合金钢的静、动态开路电位均较J55钢明显正移;J55钢在20℃时出现Warburg阻抗,随着温度的升高,Warburg阻抗消失,之后EIS谱呈现出2个时间常数,极化电阻随温度的升高先减后增;2种合金钢的EIS谱均呈现2个时间常数,其极化电阻均随温度的升高先减小后增大,60℃时最小;不同温度下,铬铝合金钢的极化电阻均较J55钢的大。

Cr-Al alloying of J55 steel used for oil and gas extraction was conducted so as to improve the corrosion resistance. The corrosion behavior of resultant Cr-Al alloyed J55 steel in 3. 5% NaCl solution was evaluated by electrochemical method,and the effect of temperature on the electrochemical impedance spectra( EIS) of J55 steel and Cr-Al alloyed J55 steel was investigated. Results indicated that the static and dynamic open circuit potentials of Cr-Al alloyed J55 steel shifted towards the positive direction as compared with those of J55 steel. The Warburg resistance of J55 steel emerged around 20 ℃,and it tended to disappear with elevating temperature. In the meantime,the EIS spectra of J55 steel and Cr-Al alloyed J55 steel at various temperatures all involved two time constants. The polarization resistance of the unalloyed and alloyed J55 steels tended to rise initially but decline later with elevating temperature,and it reached the minimum at 60 ℃. Moreover,the polarization resistance of Cr-Al alloyed steel at various temperatures was higher than that of J55 steel.