查詢結果分析
相關文獻
- 低熱膨脹球墨鑄鐵之尺寸熱穩定性分析
- 低熱膨脹球墨鑄鐵鑄造技術
- 均質化熱處理對低熱膨脹鑄鐵之熱膨脹係數及尺寸穩定性的影響
- 不同石墨型態低熱膨脹鑄鐵之尺寸熱穩定性分析
- 低熱膨脹球墨鑄鐵鑄造技術
- Computer Simulation of Electro-Thermomechanical Interactions of an Oxygen Sensor during Warm-Up
- 電子構裝產品熱應力分析軟體評估與選用
- 介面噴塗層與基板種類對Ti10/W90濺鍍層之應力分析
- 電子構裝多層結構衝擊震動之研究
- The Effect of Coating Film on the Thermal Stress of Metal Matrix Composite
頁籤選單縮合
| 題 名 | 低熱膨脹球墨鑄鐵之尺寸熱穩定性分析=Thermal Dimensional Stability of Low Thermal Expansion Ductile Cast Irons |
|---|---|
| 作 者 | 劉宗霈; 潘永寧; 潘永寧; 劉宗霈; | 書刊名 | 鑄造工程學刊 |
| 卷 期 | 41:3=166 2015.09[民104.09] |
| 頁 次 | 頁1-8 |
| 分類號 | 472.2 |
| 關鍵詞 | 低熱膨脹球墨鑄鐵; 均質化熱處理; α值; 熱應力; 尺寸穩定性; Low thermal expansion ductile cast iron; Homogenization heat treatment; α value; Dimensional stability; Finite element analysis; |
| 語 文 | 中文(Chinese) |
| 中文摘要 | 本研究之內容包含三部分:第一部分係探討均質化熱處理對於低熱膨脹球墨鑄鐵之Ni偏析程度及基地固溶C量之影響,並進一步探討上述合金組成變化對於α值的影響;最後,深入分析均質化熱處理如何影響α值之機理;第二部分係以拘束型熱循環試驗,針對不同化學組成(35%Ni、30%Ni+5%Co),但相同Ni當量之合金成份下,探討不同熱處理條件對於低熱膨脹球墨鑄鐵之形狀變形量(翹曲度)之影響,並進一步分析α值對於工件尺寸安定性的影響;第三部分係以理論模擬試片經拘束型熱循環試驗後之尺寸變化情況,藉由ANSYS模擬軟體來探討不同合金:不鏽鋼(SUS304)、一般球墨鑄鐵(SG)和低熱膨脹球墨鑄鐵(D-5)之溫度場及熱應力分布,並比較三種模擬結果之差異。最後深入分析α值對於熱應力之影響,並分析其與試片尺寸變化量之關係。本研究結果顯示:(1)Ni偏析程度隨著均質化熱處理溫度及持溫時間之增加而降低,而有利於α值之降低:且T5(1150℃/4hr/FC/750℃/4hr/WQ)熱處理幾乎可以完全消除Ni偏析現象。另一方面,固溶C量理論上應隨均質化熱處理溫度及持溫時間增加而增高,但本研究之固溶C量隨不同熱處理條件之變化並不大。為進一步瞭解固溶C量及Ni偏析程度對於α值之影響,以迴歸分析得出方程式:α(10^(-6)/℃)=0.56"Ni"_d+3.45%"C"+2.74; R^2=0.86。由上述迴歸方程式可知,欲獲致較低之α值,必須同時降低固溶C量及Ni偏析程度。(2)均質化熱處理可有效降低試片之形狀變形量,且以T5(1150℃/4hr/FC/750℃/4hr/WQ)之熱處理具有最佳之效果。(3)模擬結果顯示,合金之楊氏係數(E)與α值對於熱應力之影響較溫度梯度顯著。另,ΔPV值(尺寸安定性之無因次參數)與熱應力之關係由迴歸分析可得關係式如下:ΔPV(μm)=0.87σ_(th)(Mpa)-35.6; R^2=0.96二者呈高度線性相關,亦即試片所承受之熱應力越大,其ΔPV值亦越大。 |
| 英文摘要 | The objectives of this study are threefold: (1) To investigate the effect of homogenization heat treatment on both the degree of Ni segregation and the content of dissolved carbon in the matrix of the low thermal expansion ductile cast irons, and then to analyze the influence of compositional factor on α value. (2) To study the effects of alloy composition and homogenization heat treatment on the dimensional and shape changes of the test specimens by means of constrained thermal cyclic fatigue tests (30~200℃). (3) The temperature distribution and the thermal stress field in the test specimens after the constrained thermal cyclic fatigue tests were analyzed first by both calculation and simulation (ANSYS), and then the dimensional and shape changes of the alloys studied (Alloy D-5, Regular SG and SUS304) were calculated and compared with the measured data. In addition, the correlations among α value, thermal stress and dimensional change were analyzed. The experimental results indicate that the degree of Ni segregation can be reduced by increasing the homogenization temperature and/or time, rendering a decrease in α value. On the other hand, the dissolved C content in the matrix showed little affected by homogenization heat treatment, regardless of the fact that increasing both heat treatment temperature and time will increase the dissolved C content. Among the various heat treatment procedures employed, heat treatment T5(1150℃/4hr/FC/750℃/4hr) not only can effectively eliminate the Ni segregation, but also can reduce the C concentration in the matrix. It is clear from the equation below that in order to achieve a low α value, both the degree of Ni segregation and the dissolved C content should decrease. α(10^(-6)/℃)=0.56"Ni"_d+3.45%"C"+2.74; R^2=0.86 Finally, numerical simulation by finite element method (FEM) was employed to obtain the temperature distribution and thermal stress field for different alloys (Alloy D-5, Regular SG and SUS304) after thermal cyclic fatigue tests. Regression analysis was performed to obtain the correlation between thermal stress and ΔPV. The lower the thermal stress, the lower the ΔPV value. Also, low thermal expansion ductile irons with T5 heat treatment (1150℃/4hr/FC/750℃/4hr/WQ) exhibit the best dimensional stability due to its lowest α value (2.86x10^(-6)/℃). Besides, regression analysis was performed to obtain the correlation between the thermal stress and the PV values, with the results were shown as follows: ΔPV(μm)=0.87σ_(th)(Mpa)-35.6; R^2=0.96 The results indicate a highly positive linear correlation between the PV value and the thermal stress. |
本系統中英文摘要資訊取自各篇刊載內容。