模拟深海环境下低合金钢的阴极保护准则研究

Cathodic Protection Criteria of Low Alloy Steel in Simulated Deep Sea Environment

模拟了水下350 m的深海环境,讨论了该环境下Ni-Cr-Mo-V低合金钢的阴极保护电位准则,并且分别研究了静水压力和温度两大深海特征环境因素对其保护电位的影响。其中,最小保护电位则是通过阳极Tafel直线关系反推获得,而最大保护则是由阴极极化曲线第二拐点法得到。结果表明,Ni-Cr-Mo-V低合金钢在模拟深海环境下的最小保护电位正移,最大保护电位负移,阴极保护电位范围更加宽泛。静水压力和温度均是造成这种现象的原因,温度的作用更为显著。最后,通过-0.85 VCSE恒电位阴极极化实验进一步验证了浅海现有阴极保护电位准则对深海环境同样适用。

Cathodic protection（CP） criteria of Ni-Cr-Mo-V low alloy steel in simulated deep sea environment（350 m） were studied, while the influence of hydrostatic pressure（HP） and temperature was also discussed. The minimum protection potential was derived by extrapolating the Tafel portion of anodic polarization curves and the maximum protection potential was obtained by deciding the second inflection point in cathodic polarization curves. The results indicate that the minimum protection potential of low alloy steel shifts to positive and the maximum protection potential shifts to negative in deep ocean environment. In other words, the range of CP potential in deep ocean is broader than in shallow water, owing to the combined effect of HP and temperature of which the effect of temperature is more significant. The study suggests that the CP potential criteria suitable to shallow waters is still available for deep ocean environment, which is further confirmed through potentiostatic cathodic polarization experiments at-0.85 VCSE.