可攜式氫燃料電池儲氫氣瓶銲道防蝕研究

Abstract

燃料電池等新興能源，已被視為取代石化燃料的重要研究項目，為了將氫能有效運用在交通運輸工具與3C產品上，可攜式儲存裝置已成為普及化之重要環節之一。 本文利用鋁合金7075(Al-Zn-Mg)作為儲氫氣瓶之材料，採用鎢極惰性氣體電弧銲(GTWA)進行上蓋與瓶身接合銲接，並利用添加固化劑之水玻璃溶液塗覆於銲道表面，填補銲道之微裂縫，使氣瓶在儲氫使用環境下，銲道不易受到氫氣滲透，因而產生應力腐蝕破壞(SCC)之影響。利用田口實驗方式研究不同固化劑、固化方式、塗層厚度與烘烤溫度之最適化參數，使得銲道之耐蝕性能可有效提昇。 實驗結果由田口實驗方式求得之最佳塗覆參數，經由10%之硫酸液腐蝕驗證，添加氧化鎂作為固化劑之水玻璃塗層，相較於未添加固化劑之水玻璃塗層可提升耐腐蝕能力200%，而添加滑石粉作為固化劑之水玻璃塗層在塗層滲透深度能力相較於未添加固化劑之水玻璃塗層可提升約20%之深度。

The fuel cell new energy has been considered as an important substitute to replace fossil fuels for decades. In order to make the application of hydrogen energy popular, portable storage devices for hydrogen, such as hydrogen storage bottle, have become a critical element.

This study investigated the resistance effect of sodium silicate solution which was coated on the surface of welding zone to the Stress Corrosion Cracking (SCC). SCC was caused by storage hydrogen penetration to the micro-crack that occasionally occurred while welding the joint by the tungsten insert gas arc welding (GTWA) between bottle cover and bottle body both made of the material of aluminum alloy 7075 (Al-Zn-Mg). Four study factors, including curing agents, curing methods, coating thicknesses and baking temperatures, to the coating effect of sodium silicate were investigated. By obtaining the optimal parameters from the tested factors by Taguchi analysis method, the corrosion resistance of welding zone can be effectively improved. The obtained optimum coating parameter by Taguchi analysis method showed that corrosion resistance of tested group adding with magnesium oxide as curing agent was increased to 200% compared to the sodium solution without adding curing agent. The results also demonstrated that the penetration depth of tested group adding with talc as an curing agent was increased to 20%.