鎳元素及沃斯回火對延性鑄鐵延脆轉換溫度之影響

Effects of Nickel Addition and Austempering on Ductile-to-brittle Transition Temperature of Ductile Iron

許正勳(C. H. Hsu) ； 林冠廷(K. T. Lin)

《鑄造工程學刊》 35卷3期 (2009/09) Pp. 25-30

https://doi.org/10.29809/JTFS.200909.0003

摘要

本研究主要是針對鎳合金化延性鑄鐵施以沃斯回火處理，以獲得高強度沃斯回火延性鑄鐵(ADI)，然後在各種不同溫度下進行衝擊試驗，以探討鎳元素及沃斯回火對延性鑄鐵之延脆轉換溫度(Ductile-to-brittle transition temperature, DBTT)的影響。實驗結果顯示：相較於鑄態，添加4%Ni元素ADI不但可增加抗拉強度達33%(1027→1366 MPa)，而且可明顯降低其DBTT(-20→-70℃)。另非合金化延性鑄鐵經沃斯回火處理後，則可大幅增加抗拉強度(499→1113~1193 MPa)及可略降低DBTT(-70→-100℃)，其中360-ADI似乎有一最低的DBTT值(-100℃)。

關鍵字

鎳元素 ； 延性鑄鐵 ； 沃斯回火 ； 延脆轉換溫度

並列摘要

This study adopted austempering process to treat nickel alloyed ductile iron for attaining high strength austempered ductile iron (ADI), and then impact tests were performed at the different temperatures. The experimental aim is to explore the effects of nickel addition and austempering on ductile-to-brittle transition temperature (DBTT) of ductile irons. The results showed that ADI with 4% Ni addition not only increase the tensile strength up to 33% (1027→ 1366 MPa) as compared with Ni-DI, but also evidently has a reduction in the value of DBTT (-20→-70℃). In addition, the unalloyed ADI also has a higher tensile strength than that of as-cast (499 vs. 1113~1193 MPa), and its DBTT value is slightly reduced (-70→-100℃). In particular, 360-ADI seems to have a lowest (-100℃) value of DBTT among the ADIs.

並列關鍵字

Nickel ； Ductile iron ； Austempering ； Ductile-to-brittle transition temperature