模拟宫腔液中铜与不锈钢的电偶腐蚀

GALVANIC CORROSION OF COPPER COUPLED WITH STAINLESS STEEL IN SIMULATED UTERINE FLUID

ＶＣｕ宫内节育器中，纯铜丝与不锈钢中心丝相互偶合。为了了解这种条件下发生的电偶腐蚀，在模拟宫腔液中进行了实验研究。这时铜是阳极，不锈钢是阴极，电偶过程受阴极过程控制。铜与不锈钢偶合后的腐蚀增量随介质ｐＨ的降低而变大。如果不锈钢表面预先活化，与铜偶合时的极性相反，铜成为阴极得到保护，而不锈钢作为阳极加速了腐蚀。随着不锈钢表面的钝化，电位朝正方向移动，然后回复到通常的电偶腐蚀行为。

n VCu copper-bearing intrauterine contraceptive device, pure copper wire is coupled with OCr18Ni9 or 1Cr18Ni9Ti stainless steel wire. In order to understand its galvanic corrosion behavior, an investigation was carried out in the simulated uterine fluid. Under normal conditions, copper acted as anode, and the stainless steel, as cathode. The galvanic corrosion was controlled by cathodic process. Corrosion increment caused by the dissimilar metal contact increased with decreasing pH of the test medium. The increment value was 5% at pH 7.0, while 10% at PH 6.0. If a preactiwted stainless steel was connected with copper,reversed polarity was observed. The copper acting as cathode was proteged, while the corrosion of the stainless steel as anode was accelerated. When the stainless steel became passivated, the potential of the couple shifted towards positive and then resumed normal galvanic corrosion condition.