臺灣博碩士論文加值系統

提升汽車吸收撞擊能量的能力可以透過製作不同強度鋼板來達成，其中一種方法為裁縫式熱沖壓成形，此製程是藉由控制模內淬火的冷卻速率進而控制鋼板各部位所需的強度，一般汽車大樑的多段強度性質大多利用焊接不同厚度或材質的鋼板進行沖壓成形，而本研究將利用無需增加零件數量的裁縫式熱沖壓方式使製程更為簡化，只需藉由加熱及冷卻來變換模具各個位置的溫度，以控制板材的冷卻速率差異，進而使單一板材經過一次熱沖壓製程即可獲得多種強度性質，研究首先設計多段裁縫式熱沖壓模具並建構模型，再應用有限元素軟體進行各項模擬分析，探討模具溫度分佈以及板材成形性等相關參數之研究，最後配合實驗以驗證模擬結果的準確性。
研究結果顯示，模擬分析連續二十次熱沖壓循環，可使無冷卻系統之模具溫度升高至320℃，為確保板材高強度區能達到要求的強度，轉置時間應在10秒之內完成，模具有浮料銷的設計可避免板材成形前降溫過快，有無此設計溫差達300℃以上，模擬板材成形後的厚度與實驗成品量測值之誤差均在4%以內，成品硬度比對結果顯示，模擬在淬火強化處及熱區450℃處準確性高，而熱區550℃處則因微觀組織與實驗不同而準確性低，比較裁縫式與多段裁縫式熱沖壓成形實驗結果後可以得知，多段裁縫式熱沖壓除了和裁縫式熱沖壓同樣能使板材具有高、低強度差之外，還能使兩強度之間產生漸變過渡的多段強度，當第一熱區分別為500、550℃，第二熱區皆為450℃時，兩者板材在過渡區的硬度皆為平緩變化，然而為了使板材前段硬度保持穩定，模具兩熱區的溫差應盡量縮小，因此第一、第二熱區溫度為500、450℃可得到最佳的多段漸變強度。

Improving the ability of automobiles to absorb impact energy can be achieved by making steel sheets with different strengths. One such process is tailored hot stamping, which controls the required strength of each part of the sheet by controlling the cooling rate of in-die quenching. Most of the multistage mechanical properties of automobile beams are stamped by welding steel sheets of different thicknesses or materials. In this study, the manufacturing process will be simplified without increasing the number of parts. It is only necessary to change the temperature at each position of the die by heating and cooling, to control the difference in the cooling rate of the sheet, so that the sheet can be formed by one-time hot stamping. The multistage mechanical properties can be obtained. First, a multistage tailored hot stamping die is designed and a model is constructed. The finite element software is used to conduct various simulation, and the research on relevant parameters such as die temperature distribution and sheet formability were discussed. Finally, the accuracy of the simulation results is verified with experiments.
The simulation results show that the temperature of the die without cooling channels is increased to 320℃ after twenty cycles of hot stamping. To ensure that the high strength area of the sheet can reach the required strength, the transfer time should be completed within 10 seconds The design of the mold with floating pins can prevent the sheet from cooling too fast before forming, and the temperature difference with or without this design is more than 300℃.The error between the simulation and experiment of the formed sheet thickness is within 4%. The simulation hardness results of the sheet have high accuracy in the quenching zone and the heated zone at 450℃. Low accuracy due to different microstructures at 550°C in the heated zone. After comparing the experimental results of tailored and multistage tailored hot stamping, it can be known that both have hard and soft zones as well. However, multistage tailored hot stamping can also produce multistage strength with a gradual transition between the hard and soft zones. When the first heated zone is 500°C, 550°C, and the second heated zone is both 450 °C, the hardness of both in the transition zone changes gently. To keep the hardness of the front section of the sheet stable, the temperature difference between the two heated zones of the die should be minimized. Therefore, the best multistage gradient strength was obtained at 500°C in the first heated zone and 450°C in the second heated zone.

摘要.....i
Abstract.....ii
誌謝.....iv
目錄.....v
表目錄.....vii
圖目錄.....viii
第一章 緒論.....1
1.1 前言.....1
1.2 研究動機與目的.....2
1.3 研究方法與步驟.....4
1.4 文獻回顧.....5
1.5 論文總覽.....7
第二章 理論基礎.....8
2.1 熱沖壓製程與裁縫式板件介紹.....8
2.1.1 熱沖壓製程.....8
2.1.2 裁縫式板件.....9
2.2 熱傳遞原理.....11
2.2.1 熱傳遞機制.....11
2.2.2 熱沖壓熱傳機制.....12
2.3 熱沖壓用鋼材料性質.....13
2.3.1 錳硼鋼.....13
2.3.2 應力應變性質曲線.....13
2.3.3 熱傳導與比熱係數.....15
2.3.4 連續冷卻變態相圖.....15
2.3.5 熱摩擦係數.....16
2.3.6 介面熱傳係數.....17
第三章 研究方法.....19
3.1 多段裁縫式熱沖壓模具設計.....19
3.1.1 模具各區域規劃.....19
3.1.2 模具結構設計.....20
3.1.3 浮料銷配置.....21
3.1.4 模具加熱系統.....21
3.1.5 加熱區模具設計.....22
3.1.6 模具冷卻系統.....24
3.1.7 有冷卻區及無冷卻區模具設計.....24
3.1.8 增設第二加熱區.....26
3.2 有限元素模擬分析.....27
3.2.1 熱沖壓成形模擬參數建立.....27
3.2.2 模具有冷卻區及無冷卻區模擬參數建立.....28
3.2.3 模具加熱區模擬參數建立.....29
3.3 多段裁縫式熱沖壓成形實驗.....30
3.3.1 板材準備.....30
3.3.2 板材加熱與成形設備.....31
3.3.3 實驗流程與規劃.....32
3.4 成品檢測.....34
3.4.1 模具溫度量測.....34
3.4.2 厚度量測.....35
3.4.3 微觀組織檢測.....35
3.4.4 硬度檢測.....38
第四章 結果與討論.....40
4.1 多段裁縫式熱沖壓之模具分析.....40
4.1.1 模具加熱區分析.....40
4.1.2 模具有冷卻區及無冷卻區分析.....42
4.2 多段裁縫式熱沖壓之板材分析.....44
4.2.1 板材轉置過程分析.....44
4.2.2 板材成形性分析.....45
4.2.3 板材溫度及微觀組織分析.....46
4.3 多段裁縫式熱沖壓成品檢測.....48
4.3.1 實驗與模擬之厚度比對.....49
4.3.2 常溫熱沖壓成品檢測.....50
4.3.3 裁縫式熱沖壓成品檢測.....51
4.3.4 多段裁縫式熱沖壓成品檢測.....54
4.3.5 不同熱區模具溫度之成品硬度分佈.....58
第五章 結論與建議.....59
5.1 結論.....59
5.2 建議.....60
參考文獻.....61
Extended Abstract.....64

[1] William J Joost, "Reducing vehicle weight and improving US energy efficiency using integrated computational materials engineering," Jom, vol. 64, no. 9, pp. 1032-1038, 2012.
[2] Hossein Karbasian, A Erman Tekkaya, "A review on hot stamping," Journal of Materials Processing Technology, vol. 210, no. 15, pp. 2103-2118, 2010.
[3] Henric Lindberg, Volvo Car Corporation, "Advanced high strength steel technologies in the 2016 Volvo XC90," Great Designs in Steel Conference, 2016.
[4] Shawn Crichley, TJ Palesano, Honda R&D America Inc., "New Global Model Introduction: The All-New 2016 Honda Civic," Great Designs in Steel Conference, 2016.
[5] R George, A Bardelcik, MJ Worswick, "Hot forming of boron steels using heated and cooled tooling for tailored properties," Journal of Materials Processing Technology, vol. 212, no. 11, pp. 2386-2399, 2012.
[6] Siying Deng, Guozhe Shen, Ping Hu, Lizhong Liu, Liang Ying, "Investigations on numerical simulation of tailored tempering process based on related experiments," AIP Conference Proceedings, vol. 1532, no. 1, pp. 924-930, 2013.
[7] BT Tang, QL Wang, S Bruschi, A Ghiotti, PF Bariani, "Influence of temperature and deformation on phase transformation and Vickers hardness in tailored tempering process: numerical and experimental verifications," Journal of Manufacturing Science and Engineering, vol. 136, no. 5, 2014.
[8] Zijian Wang, Peixing Liu, Ya Xu, Yilin Wang, Yisheng Zhang, "Hot stamping of high strength steel with tailored properties by two methods," Procedia Engineering, vol. 81, pp. 1725-1730, 2014.
[9] TK Eller, L Greve, MT Andres, M Medricky, A Hatscher, Vincent T Meinders, Antonius H van den Boogaard, "Plasticity and fracture modeling of quench-hardenable boron steel with tailored properties," Journal of materials processing technology, vol. 214, no. 6, pp. 1211-1227, 2014.
[10] 陳永紘, "差異溫度模具之高強度鋼板熱沖壓成形研究," 碩士論文, 國立虎尾科技大學, 2014.
[11] Kaab Omer, Ryan George, Alexander Bardelcik, Michael Worswick, Skye Malcolm, Duane Detwiler, "Development of a hot stamped channel section with axially tailored properties–experiments and models," International Journal of Material Forming, vol. 11, no. 1, pp. 149-164, 2018.
[12] Kaab Omer, Lukas ten Kortenaar, Clifford Butcher, Michael Worswick, Skye Malcolm, Duane Detwiler, "Testing of a hot stamped axial crush member with tailored properties–experiments and models," International Journal of Impact Engineering, vol. 103, pp. 12-28, 2017.
[13] 凃君翰, "裁縫式鋼板熱沖壓之成形性分析," 碩士論文, 國立虎尾科技大學, 2019.
[14] Yuki Nakagawa, Ken-ichiro Mori, Yasutaka Suzuki, Yuki Shimizu, "Tailored tempering without die heating in hot stamping of ultra-high strength steel parts," Materials & Design, vol. 192, p. 108704, 2020.
[15] Li-Wei Chen, Chun-Han Tu, "The Effect of the tooling temperature on the mechanical properties of CSC-15B22 Steel sheets that undergo tailored tempering," International Journal of Material Forming, vol. 14, no. 4, pp. 729-738, 2021.
[16] PF Bariani, S Bruschi, A Ghiotti, A Turetta, "Testing formability in the hot stamping of HSS," CIRP annals, vol. 57, no. 1, pp. 265-268, 2008.
[17] Marion Merklein, Maren Johannes, Michael Lechner, Andreas Kuppert, "A review on tailored blanks—Production, applications and evaluation," Journal of Materials Processing Technology, vol. 214, no. 2, pp. 151-164, 2014.
[18] E. Rathakrishnan, Elements of Heat Transfer. Taylor & Francis, 2012.
[19] Malek Naderi, "Hot stamping of ultra high strength steels," Doctoral Thesis, RWTH Aachen University, 2007.
[20] 涂睿帆, 潘永村, 劉弦錦, "超高強度汽車車門防撞鋼樑開發," 鑛冶：中國鑛冶工程學會會刊, vol. 55, no. 4, pp. 27-37, 2011.
[21] A Yanagida, A Azushima, "Evaluation of coefficients of friction in hot stamping by hot flat drawing test," CIRP annals, vol. 58, no. 1, pp. 247-250, 2009.
[22] T. Altan, A.E. Tekkaya, "Sheet Metal Forming: Processes and Applications," Chapter 7 Hot Stamping, pp. 133-156, 2012.
[23] M Merklein, J Lechler, T Stoehr, "Characterization of tribological and thermal properties of metallic coatings for hot stamping boron-manganese steels," in Proceedings of the Seventh International Conference on Coatings in Manufacturing Engineering, 2008: Citeseer, pp. 1-3.
[24] Arthur B Shapiro, "Using LS-Dyna for hot stamping," in Proc. 7th European LS-DYNA Users Conference, Salzburg, Austria, 2009.
[25] Woo-Seung Lim, Hong-Seok Choi, Seok-young Ahn, Byung-Min Kim, "Cooling channel design of hot stamping tools for uniform high-strength components in hot stamping process," The International Journal of Advanced Manufacturing Technology, vol. 70, no. 5, pp. 1189-1203, 2014.
[26] "Metallic materials—Conversion of hardness values," ISO 18265, International Organization for Standardization, 2003.