- 期刊
變溫式沃斯回火製程對延性鑄鐵機械性質之影響
Effect of Variable Austempering Temperature Process on Mechanical Properties of Ductile Iron
摘要
本研究嘗試利用兩種非恆溫沃斯回火製程（持續升溫及持續降溫）方式處理延性鑄鐵，再進一步與傳統恆溫沃斯回火處理者做比較，以探討是否可藉由此變溫式沃斯回火熱處理來提升其機械性能。實驗結果顯示：相較於傳統之恆溫沃斯回火製程，不論是持續升溫(300→360℃)或持續降溫(360→300℃)方式對其顯微組織影響不大，但對殘留沃斯田鐵(γ(下标 R))之碳含量有影響，即前者會減少γ(下标 R)碳含量(1.98→1.64%C)而後者會增加γ(下标 R)碳含量(1.95→2.19%C)。在機械性質方面，持續升溫(300→360℃)方式可提升ADI之硬度和抗拉強度，而持續降溫(360→300℃)方式則可增加衝擊韌性和破裂韌性（K(下标 IC)值）。
並列摘要
In this study, two types of variable austempering temperature processes were utilized to treat ductile iron for further exploring the effects of the non-isothermal heat treatment on mechanical properties of austempered ductile iron (ADI). In the first route, the specimens after 910℃-1.5hrs austenitization were quenched into a salt bath held at 300℃ then progressively heated to 360℃. In the second route, the austenitized specimens were else quenched into a salt bath held at 360℃ then steadily cooled to 300℃. The results showed that both obtained ADIs almost had the same microstructures after the above austempering treatments, but carbon content in retained austenite was changed as compared to isothermal-treated ADI. The austempering process with temperature increasingly (300→360℃) resulted in a decrease of the carbon content (1.98→1.64%C), while another process (360→300℃) resulted in an increase of the carbon content (1.95→2.19%C). In the case of mechanical properties, the first process (300→360℃) generated the better hardness and strength, the last one (360→300℃) had an increment in impact toughness and K(subscript IC) value.