316L不锈钢强流脉冲电子束表面改性研究 Ⅱ．在模拟体液中的腐蚀行为

SURFACE MODIFICATION OF 316L STAINLESS STEEL BY HIGH CURRENT PULSED ELECTRON BEAM II．Corrosion Behaviors in the Simulated Body Fluid

采用电化学阻抗谱(EIS)和动态极化的方法研究了316L不锈钢经过强流脉冲电子束表面改性后在摸拟体液中的腐蚀行为．结果表明,电子束轰击可以有效地提高316L不锈钢在模拟体液中的耐腐蚀性．经过改性的样品其界面电容下降,极化电阻升高．5次轰击后的样品表面因其火山坑的中心位置残存MnS夹杂或小孔而更易发生点蚀．20次轰击后的样品具有最佳的耐蚀性,其腐蚀电流密度降至原始样品的1／15左右,这主要归因于电子束轰击对材料表面的选择性净化效应及反复重熔对表面缺陷的修复．

Electrochemical impedance spectroscopy （EIS） and potentiodynamic polarization procedures were used to investigate the pitting corrosion behaviors of AISI 316L stainless steel in the simulated body fluid, which was treated by high current pulsed electron beam （HCPEB）. The results showed that the corrosion resistance of 316L samples was significantly improved after HCPEB treatment, which was demonstrated by the increase of polarization resistance （Rp） and decrease of interface capacitance. The samples after 5 pulses are prone to pitting due to the existence of remnant MnS inclusions or holes in the crater centers. Comparatively, the sample after 20 pulses of HCPEB treatment shows the best corrosion resistance. Its corrosion current density has been decreased to 1/15 of the initial samples, which can be attributed to the selective surface purification effect and removal of physical damages with increasing the number of pulses.