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題名 | 回火時間對下變韌球墨鑄鐵顯微結構與機械性質的影響=The Effect of Austempering Time on the Microstructures and Mechanical Properties of Lower Bainitic Ductile Iron |
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作者 | 溫東成; | 書刊名 | 中華工商專校學報 |
卷期 | 14 1997.03[民86.03] |
頁次 | 頁48-59 |
分類號 | 472.2 |
關鍵詞 | 下變韌球墨鑄鐵; 顯微結構; 機械性質; Lower bainitic ductile iron; Microstructures; Mechanical properties; |
語文 | 中文(Chinese) |
中文摘要 | 本文旨在探討下變韌球墨鑄鐵在不同回火持溫時間的顯微結構及機械性質的變化 。 試驗首先由回火過程中電阻係數的變化決定沃斯回火處理的持溫時間, 再以 X 光繞射儀及 金相觀察來分析及判斷結構上的變化,並進行拉伸、衝擊與硬度等機械性質測試。結果顯示 大量麻田散鐵存在會使延、韌性嚴重劣化;但少量麻田散鐵的存在,經由其散佈強化效果反 而使抗拉強度,延伸率及衝擊韌性皆大幅提昇而優於窗間性質。 |
英文摘要 | This paper is aimed to evaluate the effect of martensite on the microstructures and mechanical properties of lower bainitic ductile iron. The specimens were austenitized at 900 ℃ for 1 hour and then were quenched to a salt bath at 300 ℃ for various times. The holding times were derived from the electrical resistivity variation during austempering in a vacuum heat treating system. The X-ray diffraction technique and optical metallographic method were used to study the microstructures. The mechanical testing, include tensile test, Charpy impact test and hardness test were performed to evaluate the mechanical properties. Results of this study show that a large amount of martensites were formed at initial period of the first stage of ADI transformation, which is detrimental to mechanical properties. But, toward the end of the first stage transformation, a small amount of martensites dispersed at matrix everywhere, which causes dispersion hardening and gives a more excellent of tensile strength, elongation and toughness when comparing with those treated within the processing window. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。