添加鉬、銅對鐵錳鋁鉻合金鋼腐蝕行為之影響

Effects of Mo and Cu addition on the corrosion behavior of Fe-Mn-Al-Cr alloys

本研究選用四種鐵錳鋁鉻合金鋼，藉著3.5wt%NaCl水溶液的電化學測試與硝酸、醋酸、磷酸及氫氧化鈉等四種沸騰酸（鹼）液的浸泡實驗來評估添加不同含量鉬元素與銅元素的Fe-26Mn-7Al-5.5Cr-1C 合金鋼之腐蝕行為。傳統Fe-29Mn-9Al-0.75C之鐵錳鋁合金鋼、商用304不銹鋼及410不銹鋼亦被選取測試以作比較。由測試結果發現，不含鉻鉬的鐵錳鋁合金鋼抗蝕性最差，添加1%鉬則使鐵錳鋁鉻合金具有最佳的耐蝕性。而添加1.6%鉬會促使鐵錳鋁鉻合金鋼析出碳化鉬而降低抗蝕性，不過在該合金鋼添加1%銅並無法使其耐蝕性變好。整體而言，Fe-26Mn-7Al-5.5Cr-1C-1Mo合金與傳統410不銹鋼的耐腐蝕性相當，而且在20%醋酸沸騰溶液的48小時浸泡實驗中，該合金鋼之抗蝕性則優於410不銹鋼，並逼近304不銹鋼。

The corrosion properties of four Fe-26Mn-7Al-5.5Cr-1C based alloy steels have been studied. The electrochemical tests in 3.5wt%NaCl aqueous solution and immersion tests in boiling nitric acid, acetic acid, phosphorous acid and sodium hydroxide solutions were employed to evaluate the effects of Mo and Cu addition on the corrosion behavior of these alloy steels. The Fe-29Mn-9Al-0.75C alloy, commercial 304 and 410 stainless steels were also chosen for comparison. The results showed that the Fe-Mn-Al alloy without any Cr, Mo or Cu addition had very poor corrosion resistance, whereas the alloy addition with 1% Mo and 5.5%Cr exhibited excellent performance. The corrosion resistance of Fe-Mn-Al-Cr alloy addition with 1.6% Mo was inferior due to the precipitation of carbides. The addition of 1% Cu cannot enhance the corrosion resistance. In general, the corrosion resistance of Fe-26Mn-7Al-5.5Cr-1C-1Mo alloy is similar to that of 410 SS. Especially the corrosion resistance of this alloy is even better than 410 SS, and comparable to 304 SS in the boiling 20% acetic acid solution immersion test for 48 hours.