塑变拉应力下304不锈钢在稀硫酸中的腐蚀电化学行为

Electrochemical Corrosion Behaviour of AISI 304SS under Plastic Deformation Condition with Bending Tensile Stress in Dilute Sulphuric Acid Solution

运用加载U型弯曲试样研究了塑变拉应力下304不锈钢稀硫酸体系的腐蚀电化学行为。研究了304不锈钢U型弯曲试样拉伸面在0.5mol·L-1 H2SO4溶液中不同应变量下的极化曲线以及阻抗谱的变化规律,同时研究了U型弯曲试样拉伸面在0.5mol·L-1 H2SO4+0.2mol·L-1 KCl溶液中不同应变量下的点蚀保护电位Ep随应变量的变化规律。电化学测试结果表明,U型弯曲试样应变量不同,阻抗谱曲线不同;应变量愈大,阻抗极化电阻Rp愈小,腐蚀速率升高;ΔE=Eb-Ep的大小随着应变量的增加而增大,说明塑性应变愈大,拉伸面钝化膜修复能力愈差,愈易遭受点蚀。

The corrosion electrochemical behaviors of 304 stainless steel with tensile stress under plastic deformation condition in dilute sulphuric acid were studied using U-shaped bending specimens.The tensile surface corrosion behaviors of 304 stainless steels of U bend specimens with different strains in 0.5 mol · L-1 H2SO4 solution were studied by polarization curves and impedance spectroscopy.Pitting corrosion protection potentials of the tensile surfaces of U bend specimens with different strains were studied in 0.5 mol · L-1 H2SO4 ＋ 0.2 mo1 · L-1 KCl.Electrochemical tests show that the larger the plastic strain,the smaller the polarization resistance Rp and the larger the corrosion rate;△E=Eb-Ep increased with increasing the strain,indicating that the tensile surface passive film repair ability was poor,and thus susceptible to pitting.