耐低溫衝擊性能之厚壁球墨鑄鐵研發

Study on the Production of Heavy Section Ductile Irons with Specified Low Temperature Impact Property

蘇子銘(Tzu-Ming Su)

指導教授 ： 潘永寧

國立臺灣大學/工學院/機械工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.03035

摘要

全球使用風力機裝置容量約從2000年的17,400MW增加到2010年的194,390 MW，而這些風力機裝置由幾樣厚壁的球墨鑄件所組裝，如：輪轂(Hub)、輪軸(Rotor Shaft)及機座(Main frame)等，其面臨鐵水熔煉量的增加與處理時間的延長等問題，所以鑄造廠的生產技術也需跟著提升。此外，風力機也會被裝設在低溫的環境，所以除了抗拉/降伏強度和伸長率，其低溫衝擊強度也必須符合工程上的機械性質規範(DIN EN 1563)。
本研究針對大型風力發電機之關鍵零組件，探討化學成分及熔鑄條件(球化、接種、澆鑄時間及溫度等)對於顯微組織(球化率、球墨數、波來鐵含量)及機械性質(抗拉強度、降伏強度、伸長率、低溫衝擊性能)的影響，以建立符合各種不同材質規格之合金設計及最佳熔鑄條件。此外，本研究以迴歸分析的方法，建立化學成分、顯微組織與機械性質之相關性迴歸方程式。此相關性迴歸方程式可針對不同規格要求的鑄件，提供最佳之合金設計及顯微組織，此外，亦可以由化學成分及顯微組織依據特定之迴歸方程式來預測鑄件之各項機械性質。

關鍵字

大型風力發電機 ； 球墨鑄鐵 ； 拉伸性質 ； 低溫衝擊強度 ； 合金設計

並列摘要

The global installed wind turbines capacity has increased from 17,400MW in 2000 to 194,390 MW in 2010, and these wind turbines require several heavy-section DI castings, i.e. hub, rotor shaft, main frame, etc.. Due to the increased melted mass and the extended solidification time encountered in heavy-section ductile irons, the stringent metallurgical and process control is a must and requires special attention. In addition, because the wind mills are often installed in a cold environment, the ductile iron castings normally requires excellent low temperature impact properties, in addition to meet the tensile/yield strength and elongation requirements.
The primary purpose of this research is to investigate the effects of chemical compositions and selected processing parameters, including nodularization treatment, post inoculation, pouring time and pouring temperature, on microstructures (nodularity, nodule count and pearlite percentage) and mechanical properties (tensile strength, yield strength, elongation and low temperature impact value) of key cast components used in large-scale windmills. This study has established the optimal alloy design and process conditions for different targeted castings. In addition, regression analysis had been performed to correlate the mechanical properties with chemical compositions and microstructures. The attained regression equations can be used to obtain the appropriate alloy design for castings with specified specification. Furthermore, by employing these regression equations, we can predict the mechanical properties of alloys based upon the chemical composition and microstructure.

並列關鍵字

Large-scale windmill ； ductile cast iron ； alloy design ； tensile property ； impact property

參考文獻

3. H. Itofuji, K. Kawamura, N. Hashimoto and H. Yamada, “Production and Evaluation of Heavy-Section Ductile Iron,” AFS Transactions, vol. 98, 1990, pp. 585-595.

15. Ductile Iron Data for Design Engineers, Rio Tinto Trion and Titanium, 1998, pp. 3-42, 12-9, 12-10.

1. A. Javaid and C. R. Loper, Jr., ”Production of Heavy-Section Ductile Cast Iron,”AFS Transactions, vol. 103, 1995, pp. 135-150.

2. A. Javaid and C. R. Loper, Jr., ”Quality Control of Heavy-Section Ductile Cast Irons,” AFS Transactions, vol. 103, 1995, pp. 119-134.

4. S. Nakamura, N. Sakamoto, K. Inoue, K. Ogi and K. Matsuda, “As-Cast Heavy Section Ferritic Spheroidal Graphite Cast Iron,” AFS Transactions, vol. 97, 1989,