沃斯回火球墨鑄鐵切削性之研究

The Study on Machinability of Austempered Ductile Iron

李國光(K. K. Lee) ； 楊棟賢(D. S. Yang) ； 雷添壽(T S Lei)

《鑄造工程學刊》 33卷1期 (2007/03) Pp. 24-32

https://doi.org/10.29809/JTFS.200703.0003

摘要

本論文主旨為研究3種球墨鑄鐵包括兩階段沃斯田鐵化之沃斯回火球墨鑄鐵、傳統沃斯回火球墨鑄鐵及鑄態球墨鑄鐵的切削特性，並分析其顯微組織及測試其機械性質，以作為討論分析之依據。實驗結果顯示：(1)在上、下臨界溫度內進行低溫沃斯田鐵化熱處理後，在球墨周圍或晶界處有初析肥粒鐵生成；(2)含鎳及鋁合金元素的球墨鑄鐵在兩階段沃斯田鐵化之沃斯回火後具有最大量的初析肥粒鐵，並具有最軟韌的機械性質；(3)兩階段沃斯田鐵化之沃斯回火球墨鑄鐵的切削性大致上優於傳統沃斯回火球墨鑄鐵。

關鍵字

沃斯回火球墨鑄鐵 ； 切削性 ； 兩階段沃斯田鐵化

並列摘要

This thesis has been aimed to study the machinability of three types ductile irons including austempered ductile irons treated with two-stage austenitizing, conventional austempered and as-cast ductile irons. In order to analyze the relationship between the machinability with the structure and properties of the irons, the characteristic of microstructures was analyzed and also the testing of mechanical properties of hardness and toughness was conducted.
The results of this research show that: (1) The microstructure of austempered ductile irons treated with a second stage low-temperature austeniting within the upper and lower critical temperatures existed a certain among of pro-eutectoid ferrite grains which precipitated along graphite nodular and or grain boundaries; (2) The austempered ductile irons alloying with Ni and Mo and treated with two-stage austenitizing had a microstructure with larger among of pro-eutectoid ferrite grains, and with mechanical properties softer and tougher; (3) In general, the machinability of austempered ductile irons treated with two-stage austenitizing was better than that of which treated with conventional one-stage process.

並列關鍵字

Austempered ductile irons ； machinability ； two-stage austenitizing