循环静水压力对牺牲阳极阴极保护的影响

EFFECT OF CYCLIC HYDROSTATIC PRESSURE ON SACRIFICIAL ANODE CATHODIC PROTECTION

实验模拟了常压和3.5 MPa静水压力循环作用下,牺牲阳极阴极保护系统(CP)中阳极对阴极的保护。利用电化学测试法,结合SEM分析,对CP系统进行了电化学测量和腐蚀形貌观察,并对腐蚀产物进行了XRD成分分析。结果表明:在循环静水压力下,阴极的保护电位升高;牺牲阳极表面形成了一层相对致密的腐蚀产物壳层,导致其工作电位升高,放电能力下降;CP系统中斜率参数增大,牺牲阳极对阴极的保护效果变差。

The protective performance of cathodic protection （CP） system consisted of Zn-Bi sacrificial anode and Ni-Cr-Mo-V steel was investigated by electrochemical measurements and morphology observation. The shallow-deep water alternating cycle was simulated by immersed the CP system to cyclic conditions of 16 h immersion at atmospheric pressure and 8 h pressurized at 3.5 MPa. The experiment results indicated that the cyclic hydrostatic pressure had significant influence on the CP system. Comparing with the counterpart at atmospheric pressure, the anode potential instantaneously responded to the cyclic hydrostatic pressure and the discharge performance of anode decreased due to the deposition of corrosion product. At the cyclic hydrostatic pressure, the CP system exhibited the higher slope parameter, which indicated that the CP system can not provide the adequate protection for Ni-Cr-Mo-V steel.