316L不锈钢在模拟体液中的腐蚀行为

Corrosion Behavior of 316L Stainless Steel in Simulated Body Solution

目的研究316L不锈钢生物医用材料植入体内初期的表面行为。方法在模拟体液中,采用浸泡实验,表征了316L不锈钢浸泡不同时间的表面形貌、润湿性及耐腐蚀性。结果白光干涉测试结果表明,样品表面粗糙度随浸泡时间的延长而变大。浸泡1 d后,在样品表面出现大量无规则的腐蚀坑,腐蚀坑内出现金属的溶蚀。润湿性测试结果显示,随浸泡时间的延长,316L不锈钢的接触角减小,亲水性增强,表面能增加。电化学测试表明,浸泡1周后,316L不锈钢的自腐蚀电流为浸泡前的3倍多,腐蚀速度增大,耐腐蚀性变差。结论在模拟体液中,316L不锈钢表面存在局部腐蚀,材料的表面形貌、成分、润湿性及耐腐蚀性均发生改变。

The work aims to investigate the surface behavior of 316 L stainless steel（316L SS） implanted in the body at the preliminary stage. The surface morphology, wettability and corrosion resistance of 316 L SS in simulated body solution based on immersion test were characterized. The results of white light interference test showed that surface roughness increased with increasing immersion time. A large amount of irregular corrosion pits were found on the surface of 316 L SS after immersion for 1 day. Metal ions were released in the corrosion pits. Wettability test results showed that, with prolonged immersion time, the contact angle of 316 L SS decreased, while the hydrophily improved and surface energy increased. The electrochemical test indicated that self-corrosion current of 316 L SS after immersion for 1 week was threes times the amount of the one before immersion. The corrosion rate increased and corrosion resistance became worse. Local corrosion on the surface of 316 L SS occurs in simulated body solution. The surface morphology, composition, wettability and corrosion resistance of 316 L SS are changed.