沃斯田鐵系高溫變形阻抗之研究

A Study on the Hot Deformation Resistance of Austenitic Stainless Steels

陳威廷(Wei-Ting Chen) ； 吳翼貽(Ye-Ee Wu) ； 關聖立(Sheng-Lih Kuan)

《鍛造》 16卷2期 (2007/07) Pp. 13-29

https://doi.org/10.29791/Forging.200707.0003

摘要

本研究目的為應用多元迴歸分析法建構－適用於沃斯田鐵系不銹鋼之高溫變形阻抗預估方程式。本研究係用熱加工模擬試驗機對不同合金成分之沃斯田鐵系不銹鋼（304L、304H、304N、316L及316LN）於不同加熱溫度及加工製程參數進行高溫壓縮試驗；將各鋼種實驗後所得數據轉換成真實應力－真實應變曲線以探討不同實驗條件下鋼種的高溫機械性質；最後，應用實驗數據先行建構高溫變形阻抗預估方程式，再利用多元迥歸分析取得組成方程式的相關係數，以代入所建構之組成方程式，完成高溫變形阻抗預估方程式的建立工作。
在本研究內先行應用304L、304H、304N及316L等鋼種在固定工程應變率(e=2 sec^(-1))，溫度範圍為1000℃≦T≦1200℃，及感變範圍為0.16≦ε≦0.5之條件下，建構適用於沃斯田鐵系不誘鋼高溫變形阻抗預估方程式。高溫變形阻抗為應變、應變速率及溫度之函數，且活化能為合金元素的函數，故可應用多元線性迥歸分析求得活化能預估方程式。
為確定已建構公式之準確性，應用不銹鋼316LN依照預估之實驗條件進行高溫壓縮試驗，並將實驗值與預估值做比較：實驗結果顯示高溫變形阻抗應力之預估值均大於實驗值，準確性約為83%；活化能預估值與活化能平均值差異約為2.7%，顯示活化能預估方程式之準確性是可被接受的。

關鍵字

高溫變形阻抗 ； 組成方程式 ； 沃斯田鐵系不銹鋼

並列摘要

This study was aimed to construct a constitutive equation suitable for the prediction of hot deformation resistance of Austenitic stainless steels by multiple regression analysis. 5 stainless steels, 304L, 304H, 304N, 316L. and 316LN having different alloying compositions were used in this study as experimental materials. Hot compression tests based on various combinations of process parameters were done by the thermo-mechanical simulator. Load-displacement curses were transferred into the true stress-true strain curves to analyze hot workability.
Based on experimental results, the activation energy for hot deformation of any 300 series stainless steel can be estimated as a function of chemical compositions. A constitutive equation for hot deformation resistance prediction under constant engineering strain rate (e-2 see^(-1)) was proposed and verified the accuracy between the prediction value and experimental value was within 17%.

並列關鍵字

Hot deformation resistance ； Constitutive equation ； Austenitic stainless steels