35ACR之機械性質與破斷面顯微結構隨回火溫度的演化探討

The Evolution of the Mechanical Properties and Microstructure of 35ACR Steel with Tempering Temperature

林俊宏(J. H. Lin)；陳聖祈(S. C. Chen)；許進忠(J. J. Hseu)；葉松瑋(S. W. Yeh)

35ACR ； 熱處理 ； 回火脆性 ； 機械性質 ； 微觀組織 ； 35ACR ； heat treatment ； tempering brittleness ； mechanical properties ； microstructures

鑄造工程學刊

48卷2期（2022 / 12 / 01）

25 - 30

繁體中文;英文

本研究選用材料特性優異以及在業界應用範圍廣泛的35ACR鋼材，將鋼料矯直後，整個材料熱處理過程可分為（1）在870°C持溫一個小時來進行正常化熱處理（2）放入約攝氏80℃度的油中淬火（3）將經過淬火後的試片在150～700℃的溫度區間以每隔50℃為一間隔溫度，進行回火兩小時之回火熱處理。並將各種熱處理條件之測試樣品分別進行拉伸試驗、衝擊、硬度測試與電子顯微鏡的觀察來分別測量其抗拉伸強度，降伏強度、伸長率、衝擊值與硬度值等機械性質與微觀的顯微斷面組織觀察。結果顯示在35ACR經回火熱處理後，整體具有優異的機械性質表現，只有在250℃的回火溫度區間，表現出些微的低溫回火脆性的特性。

In this study, 35ACR steel, which is widely used in the industry, is selected. After straightening the steel, the entire heat treatment process of the material can be divided into (1) normalizing heat treatment at 870°C for one hour (2) placing it in (80°C)quenching oil (3) The quenched samples were tempered for two hours in the temperature range of 150~700°C with an interval temperature of 50°C. The test samples under various heat treatment conditions were subjected to tensile test, impact test, hardness test and electron microscope observation to measure the tensile strength, yield strength, elongation, impact value and hardness value, respectively. The results show that 35ACR has excellent mechanical properties as a whole after tempering heat treatment. Only in the tempering temperature range of 250°C, it shows a slight low-temperature tempering brittleness.

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