薄鑄件縮狀石墨鑄鐵研製

A Study on Thin Section Compacted/Vermicular Cast Iron

林正豪(C. H. Lin) ； 朝春光(C. K. Chao) ； 洪敏雄(M. H. Hon)

《鑛冶：中國鑛冶工程學會會刊》 30卷2期 (1986/06) Pp. 81-91

https://doi.org/10.30069/MM.198606_30(2).0007

摘要

製造薄鑄件縮狀石墨鑄鐵時，由於冷却速率快，容易在鑄件中產生碳化物。而增加矽鐵後接種量，雖可消除碳化物，却造成高球墨率。本實驗以添加1%含鈦縮墨處理合金，探討提高原鐵水中的矽含量，及改變矽鐵對於縮墨鑄鐵組織的影響。鋁具有石墨化及反球化的效應，本文亦探討添加鋁（1～3wt%）對縮墨鑄鐵組織的影響。實驗結果顯示：以1%含鈦合金處理矽含量為1.9～2.8%鐵水，以0.05%矽鐵後接種，卽可在厚度≧6mm鑄件中，得到滿意的縮墨組織，且不產生碳化物。3mm鑄件中，增加矽含量及後接種量，有利於減少碳化物，而以0.2%矽鐵後接種，矽含量約為2.6%，可得較高的縮墨率，且不產生碳化物。鑄件不論厚簿，矽含量在2.8%左右皆有急速降低縮墨率的現象。添加鋁，可減少鐵水遇冷度，並使縮墨外形變粗變短。添加1%鋁，卽可消除3mm鑄件的碳化物，且縮墨率優良。

並列摘要

When a thin section of compacted graphite cast iron was being casted, due to the fast cooling rate, it would accompany with massive carbide. By increasing the amount of ferrosilicon in post-inoculation, the carbide could be eliminated completely, but the percentage of nodularity would be very high. In this study, the base iron was treated with 1% C. G. alloy. The effects of varied Si contents and ferrosilicon post-inoculations on compacted graphite cast iron structures were investigated. 1-3% Al was added as alloying element to study the effects of Al on the structures of compacted graphite cast iron. Cast iron with 1.9-2.8% Si, which was treated with 1% C. G. alloy and 0.05% ferrosilicon post-inoculation, has shown that a desired graphite structure and no carbide was obtained for section thickness ≥6mm. In 3mm section, the carbide percentage decreased with increasing Si contents and ferrosilicon post-inoculation. It could be achieved better compacted graphite cast iron structure with Si content at about 2.6%, and 0.2% ferrosilicon post-inoculation. The compactization ratio of graphite decreased rapidly in Si content at about 2.8% in all section sizes. Al could decrease chilling tendency and make the graphite shape thicker and shorter. Adding 1% Al in base iron, a good compacted graphite structure without carbide can be obtained even in 3mm section.