镍元素对沃斯回火球墨铸铁微结构及机械性质之影响-YOKEnet.PDF

鎳元素對沃斯回火球墨鑄鐵微結構及機械性質之影響 Effects of nickel element on microstructure and mechanical properties of ADI 許正勳 *呂佳鴻 **韓濟帆 ** Cheng-Hsun Hsu* Jia-Hong Lu** Chi-Fan Han** * 大同大學 材料工程研究所教授 ** 大同大學 材料工程研究所研究生 * Professor, Department of Materials Engineering, Tatung University **Graduate student, Department of Materials Engineering Tatung University 摘要 本研究乃針對非合金和含鎳元素(4wt%) 兩種球墨鑄鐵素材進行ADI 熱處理 即先施以沃斯， 田體化處理 (910℃-1.5hrs)後 ，淬火至不同回火溫度(分別為300℃、360℃)並持溫2 小時後再空 冷之 ；藉由微結構觀察 、殘留沃斯田體含量 、硬度 、拉伸及衝擊韌性等試驗來瞭解 Ni 元素對 ADI微結構及機械性質之影響 。由實驗結果得知 Ni的添加可使 ADI ：(1)有較多的殘留沃斯田 體含量 ；(2)降低沃斯回火溫度對 殘留沃斯田體含量之影響 ；(3)經300℃-2hrs處理可提高抗拉強 度至 1377MPa ，但對衝擊韌性與伸長率影響不大 。 關鍵詞 ：球墨鑄鐵 、沃斯回火熱處理、鎳元素 、微結構 、機械性質 Abstract In this study, both the materials consisting of unalloyed DI and 4wt% Ni-alloyed DI were performed austempered treatment. They were austenitized at 900℃ for 1.5 hrs before quenched in a salt bath of 300℃ and 360℃ for 2 hrs, respectively, and finally air-cooled to room temperature. And then, microstructure observation, retained austenite measurement, hardness, tensile and impact tests were all carried out for understanding the effect of nickel addition on microstructure and mechanical properties of ADI. The results are showed as the follows: (1) Ni-alloyed ADI has the more retained austenite content than unalloyed DI; (2) 4% nickel addition can reduce the effect of austempering temperature on retained austenite content of ADI; (3) Ni-alloyed ADI austempered 300℃ for 2 hrs has the highest tensile strength about 1377 MPa, while its elongation an