利用液相沉積法製備TiO 2抗氫腐蝕薄膜於316L基材之研究

Preparation of a Thin TiO2 Film Resistant to Hydrogen Corrosion on a 316L Substrate Through Liquid Deposition

本研究利用電化學充氫的方式針對氫能專用的316L不鏽鋼管件銲道進行腐蝕特性測試。316L基材在電化學充氫後，316不鏽鋼銲件的表面出現的缺陷皆會加速銲件的腐蝕速度，因此研究中利用液相沉積製備二氧化鈦（TiO2）薄膜可以有效阻隔316L不鏽鋼與氫原子反應，抗腐蝕效果經由腐蝕電化學分析獲得證實，316L的腐蝕電流4.1×10-5 A，但在TiO2鍍膜後降低至9.6×10-6A，電化學充氫後之TiO2/316L基板腐蝕電位為211.31 mV，腐蝕速率為2.3×10-7 A，極化阻抗為1.7*104Ω，其數值皆優於充氫前後未處理之316L基材，這代表如果將TiO2抗蝕膜層鍍在316L基材表面，不但可以減少充氫帶來的攻擊，也可以提升氫攻擊後抗腐蝕的效果。

In this study, electrochemical hydrogen charging was used to test the corrosion characteristics of the weld bead of 316L stainless steel pipe fittings used in hydrogen energy production. After the electrochemical hydrogenation of the 316L base material, surface defects on the stainless steel weldment accelerated the rate of corrosion. These results indicated that the preparation of thin TiO2 molds through liquid phase deposition can effectively block the reaction between 316L stainless steel and hydrogen atoms. Electrochemical analysis revealed an anticorrosion effect. After the pipe fittings were coated with TiO2, the initial corrosion current of 4.1×10−5 was reduced to 9.6×10−6. In addition, the corrosion potential, corrosion rate, and polarization resistance of the TiO2/316L substrate after electrochemical hydrogenation were 211.31 mV, 2.3×10−7 A, and 1.7×104Ω, respectively, which are all more favorable than the values obtained for the untreated 316L substrate before and after hydrogen charging. These findings suggest that TiO2 coating on the surface of 316L substrates can mitigate hydrogen charging attacks and enhance the subsequent anticorrosion effect.