表面技术2016，Vol.45Issue(3)：12-16,126,6.DOI:10.16490/j.cnki.issn.1001-3660.2016.03.003
拉应力对2205双相不锈钢耐点蚀性能的影响
Effect of Tensile Stress on Pitting Resistance of 2205 Duplex Stainless Steel
摘要
Abstract
ABSTRACT:Objective To study the effects of tensile stress on pitting-resistance of 2205 duplex stainless steel at 40 ℃ and 60℃. Methods The characteristics of potentiodynamic polarization was investigated under different elastic tensile stress of 0 MPa, 140 MPa and 540 MPa in 3. 5% NaCl solution below the critical pitting temperature of 40℃ and around the temperature of 60℃. The effect of different tensile stress on the impedance characteristics of 2205 duplex stainless steel was also analyzed. Results The potentiodynamic polarization curves showed a relatively stable pitting potential under condition of 140 MPa, which was about 0. 7 V and 0. 8 V at 40℃ and 60℃, respectively. However, applying tensile stress of 540 MPa significantly decreased the pitting poten-tial from 1. 0 V to 0. 3 V. The electrochemical impedance spectra (EIS) exhibited single impedance arc with high value of electric resistance, and the resistance was decreased by applying stress. As temperature increased up to 60℃, high value of impedance re-sistance was achieved under stress of 0 and 140 MPa, while a pitting initiation characteristics was observed for the EIS under 540 MPa at OCP. At bias polarization of 600 mV, the pitting arcs were observed under 0 MPa and 540 MPa, but the resistance under 140 MPa was still high. The fitting results by using equilibrium circuit plots combined with surface morphologies showed that there was no pitting occurring at 40 ℃, the resistance of the passive film Rp was around 30 000 Ω·cm2 which was not significantly af-fected by applying tensile stresses. At the temperature of 60 ℃, the resistance of passive film decreased significantly. Under the condition of OCP 540 MPa, pitting corrosion occurred, the impedance values decreased from about 20 000Ω·cm2 to about 10 000Ω·cm2 . At bias polarization of 600 mV, pitting occurred under both 0 MPa and 540 MPa, while there was no pitting under 140 MPa at 60 ℃. Conclusion At 40 ℃ and 60 ℃, the pitting of 2205 duplex steel could be inhibited under the stress of 140 MPa while the application of 540 MPa accelerated the occurrence of pitting.关键词
双相不锈钢/拉应力/点蚀/电化学阻抗谱/动电位极化/临界点蚀温度Key words
2205 duplex stainless steel/tensile stress/pitting/electrochemical impedance spectroscopy/potentiodynamic po-larization/critical pitting temperature分类
矿业与冶金引用本文复制引用
张东海,刘睿,程从前,赵杰..拉应力对2205双相不锈钢耐点蚀性能的影响[J].表面技术,2016,45(3):12-16,126,6.基金项目
国家自然科学基金(51571051,51101024,51171037)@@@@Supported by the National Natural Science Foundation of China (51571051,51101024,51171037) （51571051,51101024,51171037）
