中矽型球墨鑄鐵件的開發

The Development of Medium Silicon as-cast Ductile Iron Castings

張世穎(S. Y. Chang) ； 張文雄(W. H. Chang) ； 趙苡捷(Y. C. Chao) ； 林介宇(J. Y. Lin)

《鑄造工程學刊》 43卷4期 (2017/12) Pp. 17-24

摘要

高矽含量的球墨鑄鐵有較佳的高溫特性(高溫抗拉強度、高溫疲勞限，耐氧化能力及抗熱陡震等)，因此常被做為耐熱鑄件的材料之一。本研究針對鑄件的使用環境及條件的考量下，提高矽含量生產中矽型球墨鑄鐵，並對其機械性質進行探討。結果顯示，雖然一般型和中矽型球墨鑄鐵在室溫下具有相同水準的抗拉強度。由於矽元素對基地的固溶強化作用，中矽型球墨鑄鐵的降伏強度會比一般型提高約20~30%。中矽型球墨鑄鐵為全肥粒鐵基地，延伸率會高於一般型球墨鑄鐵。鑄件在實際使用條件下需承受熱陡震，經由提高矽含量後可延長鑄件使用壽命，壽命隨著矽含量的增加而延長。

關鍵字

球墨鑄鐵 ； 熱陡震 ； 耐熱性 ； 固溶強化

並列摘要

High silicon ductile cast irons have good mechanical properties in high temperature (eg: high temperature strength, fatigue life, resistance to oxidation, and thermal shock). As a result, Hi-Si ductile irons are one kind of the thermal resistance materials in high temperature. In this study, it was aimed to assess the mechanical properties of ductile iron castings with medium silicon contents in high temperature conditions. The results show that both the normal grade and medium Si ductile cast irons have the same level of tensile strength in room temperature, but the yielding strength of medium silicon ductile iron was better than that of the normal grade by about 20~30% due to solid solution strengthening of silicon. Because of the graphitizing effect of silicon, the matrix of Med-Si ductile cast irons are fully ferritic, and also the elongations of Med-Si ductile iron castings are higher than those of the normal grades. At the elevated temperature conditions, the Med-Si ductile iron castings can provide an increased working life as the silicon content increases.

並列關鍵字

Ductile iron ； Thermal shock ； Thermal resistance ； Solid solution strengthen