稀土元素（鑭）對延性鑄鐵球化率衰退的影響

The Influence of Rare Earth Element (Lanthanum) on Nodularity Decay of Ductile Iron

唐自標(Tzu-Piao Tang) ； 李承諺(Cheng-Yen Lee)

《鑄造工程學刊》 36卷2期 (2010/06) Pp. 1-6

https://doi.org/10.29809/JTFS.201006.0001

摘要

本實驗主要目的在於研究添加稀土元素（鑭）對延性鑄鐵球化率衰退的影響，使材料開發者能加以運用。以5公斤週波爐，利用純度99%以上鑭取代球化劑添加到鐵水中，以100% FCD-450回收料熔煉，爐內球化方式進行球化反應，並將鐵水持溫至球化元素衰退過程中，間隔固定時間出湯，以連續觀察球化效果和球化衰退的趨勢。鑭的抗衰退效果可有效延長球化時間，接種效果和球化效果同時具備是鑭的特色之一。另外也在經鑭處理的球墨內部觀察到漩渦狀組織，可做為鑭球化石墨的特徵，此構造之特色為在球墨斷面觀察到石墨生長方向改變。
數據顯示，鑄件添加2%鑭完全代替鎂球化劑，以0.5%的矽鐵做接種處理，球化反應開始後的10分鐘內，可得到80%的球化率，雖然比不上同球化時間的鈰90%，但衰退緩慢，球化反應開始30分後，球化率降到65%，進入縮墨的區間，而且碳化物開始明顯增加。

關鍵字

稀土元素 ； 鑭 ； 球墨鑄鐵 ； 球化率

並列摘要

The main purpose of this paper is to investigate the influence on nodularity decay of ductile iron which add rare earth elements. (Lanthanum). We added Lanthanum which pure rate above 99% in place of nodulation to nodularize in an 5kg electric furnace. The melt came from 100% FCD-450 returns. Then keep degree to observe the decay of nodulation. The effecf of anti-decay that make Lanthanum can extend nodulation time. Lanthanum can be inoculant and spheroidiser at same time. We also found a structure in the center of nodular graphite like an eddy. It just like characteristic marks that means Lanthanum's effect of nodulation. The formation of graphite changed that doesn't continuously in a nodular graphite cross-section.
Data shows that use Lanthanum 2% to replace magnesium to be nodularizer, and add FeSi 0.5% to inoculant in thin wall ductile iron. When nodularize 10 minutes, we got 80% nodularity, less than cerium in same nodulation time. when nodulation over 30 minutes, nodularity below 65%. Carbide increased in matrix after 30mins.

並列關鍵字

Rare earth element ； Lanthanum ； Nodular graphite cast iron ； nodularity