本研究是針對鈷、鎳合金添加後,對ADI機械性質、恆溫變態的影響,以及和未添加合金的原始態作一比較,本文所研究的球墨鑄鐵包含三種成分(不含其他合金)、(4﹪鈷)、(4﹪鎳),並藉由球墨數的不同比較對機械性質的影響,材料先在900℃進行沃斯田鐵化處理,時間為1.5小時,之後在300℃~360℃範圍進行沃斯回火處理,時間為1~3小時。所要探討的機械性質包括抗拉強度、伸長率、硬度、衝擊值、破裂韌性及殘留沃斯田鐵量和碳含量。 實驗結果顯示,在低溫進行沃斯回火時,A、B、C合金的微結構在恆溫變態1~3小時內變化不大,當恆溫變態溫度升至360℃時各種成分的ADI其微結構都會隨恆溫變態時間的增加而改變。 在機械性質方面,經過熱處理的球墨鑄鐵,不管有無添加合金其拉伸強度皆有提升,在各種機械性質的測試之下,均有一最佳化的條件存在,而經由成分分析發現,鈷與鎳合金的強化機構皆為散佈強化,在本次實驗中皆無偏析的現象發生,而石墨數和基地組織確實會對機械性質造成某些程度上的影響。
The study focus on the influence of alloying elements with cobalt and nickel added on mechanical properties, constant temperature transformation of ADI. Comparing them with the original situation that added nothing with alloying element. The article in this study among three ingredients(without alloying element),(4﹪cobalt),(4﹪nickel). By doing the difference of graphite numbers to compare the influence of mechanical properties. The material first austenization at 900℃ and holds time for 1.5hrs,then austempering processing at300℃~360℃ and holds time for 1~3hrs. The mechanical properties of discussion including tensile strength, elongation, hardness, impact values, fracture toughness and amount of retained austenite. The experimental results showed when austempering in lower temperature, the microstructure of A,B,C alloying elements almost unchanged during 1~3hrs. In the portion of mechanical characteristics, the ductile iron through heat treatment will promote whether add alloying element or not. For the testing of all kinds of mechanical properties, all have the optimum existence. By the observation of ingredient analysis, cobalt and nickel are almost no segregation phenomenon. The graphite numbers and base organization really affect the mechanical properties in some level.