摘 要
本研究利用光學顯微鏡、掃描式電子顯微鏡、能譜分析、X光繞射分析儀、衝擊試驗、硬度試驗及酸液腐蝕檢測等方法，分別來檢測Sill-Cu2型高矽鑄鐵的微觀晶相組織，組成成分、衝擊能量、硬度與抗腐蝕性等性質。晶相組織顯示了石墨組織的存在，由能譜分析與X光繞射分析結果發現Sill-Cu2型高矽鑄鐵的主要基地為富矽的鐵相Fe3Si相，而衝擊試驗與硬度試驗的結果顯示了材料的室溫衝擊值並不高只有0.65J/cm2且硬度高達HRC 50.5，這也顯示了Fe3Si相可能是造成高矽鑄鐵脆性與高硬度的可能原因之一。此外在重量百分比濃度98%濃硫酸，溫度為150℃，的72小時腐蝕實驗後發現其腐蝕速率為2.35 g‧m-2‧h-1，顯示高矽鐵鑄鐵對於硫酸具有極佳抗腐蝕性，本研究對國內業者之硫酸循環系統設備和管道選材具有參考數據。
ABSTRACT
Microscope, scanning electron microscope, energy spectrum analysis, X-ray diffraction analyzer, impact test, hardness test and acid corrosion test are employed to observe the microstructure、composition、mechanical properties and corrosion property of the Sill-Cu2 type silicon rich cast irons. The results indicated that the matrix phase of Sill-Cu2 type silicon rich cast iron is Fe3Si phase. The impact test shows the value as low as 0.65J/cm2 and the hardness test has a value as high as HRC 50.5. These results of low impact value and high hardness might be due to the brittle matrix phase of the Fe3Si matrix. In addition, the corrosion test was carried out with 98wt% sulfuric acid at a temperature of 150°C for 72-hour. It was found that the corrosion rate was 2.35 g‧m-2‧h-1, showing that high silicon iron cast iron has excellent corrosion resistance to sulfuric acid. This study might provide reference data for domestic industry players in selecting sulfuric acid circulation system equipment and pipeline materials.Keywords: Microscope, SEM, EDX, XRD