锻压技术

40Mn钢热变形行为及加工图研究

英文标题：Research on hot deformation behavior and processing map for 40Mn steel

作者：孔得磊雷丽萍曾攀

单位：清华大学

分类号：TG142.1+4

出版年,卷(期):页码：2019,44(3):122-132

摘要：

为研究40Mn钢的热变形行为和动态再结晶特征，在Gleeble-1500D热模拟机上对40Mn钢进行了等温压缩实验，建立了高温流变应力模型和加工图，并采用光学显微镜观察压缩后试样的显微组织。结果表明：40Mn钢高温流变应力可采用包含动态再结晶特征的双曲正弦模型来描述。实验条件下获得的热变形平均变形激活能为300.48 kJ·mol-1。40Mn钢具有动态再结晶软化特征，不同应变下加工图有明显区别。将其加工图分为加工硬化-动态回复阶段和动态再结晶阶段。在加工硬化-动态回复阶段，存在两个加工失稳区，分别位于900 ℃-1 s-1和1200 ℃-1 s-1附近，机理分别为绝热剪切带和晶界开裂；在动态再结晶阶段，存在一个加工失稳区，位于低温高应变速率区域，机理为绝热剪切带，存在一个最佳加工区域为温度1050~1150 ℃，应变速率0.003~0.01 s-1，其为动态再结晶区域。在850 ℃-1 s-1条件下，金相图中观察到“项链”组织，验证了加工图的可靠性，可为热加工性能评估和锻造工艺研究提供指导。

The isothermal compression test was carried out by Gleeble-1500D thermo-mechanical simulator to study the hot deformation behavior and dynamic recrystallization of 40Mn steel. Then, the high-temperature rheological stress model and the processing map were established, and the microstructure of compressed specimens was observed by the Optical Microscope. The results show that the high temperature rheological stress of 40Mn steel can be described by a hyperbolic sine model including dynamic recrystallization characteristic, and the average deformation activation energy of thermal deformation is 300.48 kJ·mol-1. Therefore, 40Mn steel has the characteristic of dynamic recrystallization softening, and there are obvious differences in the processing map under different strains. Furthermore, the processing map is divided into work hardening-dynamic recovery stage and dynamic recrystallization stage. In the work hardening-dynamic recovery stage, there are two processing instability regions located at 900 ℃-1 s-1 and 1200 ℃-1 s-1 respectively, and the mechanisms are adiabatic shear zone and grain boundary cracking respectively. In the dynamic recrystallization stage, there is a processing instability zone located in the low-temperature and high-strain-rate zone, and the mechanism is adiabatic shear zone. There is an optimal processing zone with temperature 1050-1150 ℃ and strain rate 0.003-0.01 s-1, which is a dynamic recrystallization zone. The ‘necklace’ microstructure at 850 ℃-1 s-1 is observed, which verifies the reliability of the processing map and provides the guidance for the evaluation of hot workability and research the forging process.

基金项目：

国家重点研发计划(2017YFB0701800)

孔得磊(1993－)，男，硕士研究生，E-mail： kdl16@mails.tsinghua.edu.cn；通讯作者: 雷丽萍(1968－)，女，博士，副研究员，E-mail: leilp@mail.tsinghua.edu.cn

参考文献：

［1］陈飞. 热锻非连续变形过程微观组织演变的元胞自动机模拟
［D］. 上海:上海交通大学. 2012.

Chen F. Simulation of Microstructure Evolution during Discontinuous Hot Forging Processes Using Cellular Automaton Method
［D］. Shanghai: Shanghai Jiao Tong University. 2012.

［2］Mecking H, Kocks U F. Kinetics of flow and strain-hardening
［J］. Acta Metallurgica, 1981，29(11): 1865-1875.

［3］Sellars C M, Whiteman J A. Recrystallization and grain growth in hot rolling
［J］. Metal Science, 1979, 13(3-4):187-194.

［4］Wahabi M E,Cabrera J M,Prado J M. Hot working of two AISI 304 steels: A comparative study
［J］. Materials Science and Engineering A, 2003, 343(1-2):116-125.

［5］Prasad Y V R K, Gegel, H L, Doraivelu S M, et al. Modeling of dynamic material behavior in hot deformation: Forging of Ti-6242
［J］. Metallurgical Transactions A, 1984, 15(10): 1883-1892.

［6］李庆波, 周海涛, 蒋永峰, 等. 加工图的理论研究现状与展望
［J］. 有色冶金设计与研究, 2009, 30(4):1-6.

Li Q B, Zhou H T, Jiang Y F, et al. Research status quo and prospect of the theory of shop drawing
［J］. Nonferrous Metals Engineering and Research, 2009, 30(4):1-6.

［7］曾卫东, 周义刚, 周军, 等. 加工图理论研究进展
［J］. 稀有金属材料与工程, 2006, 35(5): 673-677.

Zeng W D, Zhou Y G, Zhou J, et al. Recent development of processing map theory
［J］. Rare Metal Materials and Engineering, 2006, 35(5): 673-677.

［8］肖宏超, 刘楚明, 徐璐, 等. Mg-10Gd-4.8Y-0.6Zr镁合金热变形行为与加工图
［J］. 中国有色金属学报, 2013, 23(2):303-310.

Xiao H C, Liu C M, Xu L, et al. Deformation behavior and processing map of Mg-10Gd-4.8Y-0.6Zr magnesium alloy
［J］. The Chinese Journal of Nonferrous Metals, 2013, 23(2):303-310.

［9］鞠泉, 李殿国, 刘国权. 15Cr-25Ni-Fe基合金高温塑性变形行为的加工图
［J］. 金属学报, 2006, 42(2):218-224.

Ju Q, Li D G, Liu G Q. The processing map of hot plastic deformation of a 15Cr-25Ni-Fe base superalloy
［J］. Acta Metallurgica Sinica, 2006, 42(2):218-224.

［10］李展志, 李慧中, 王海军，等. 6069铝合金的热变形行为和加工图
［J］. 粉末冶金材料科学与工程, 2011, 16(2):155-161.

Li Z Z, Li H Z, Wang H J, et al. Hot deformation behavior and processing map of 6069 aluminum alloy
［J］. Materials Science and Engineering of Powder Metallurgy, 2011, 16(2):155-161.

［11］邱旭东, 王振军, 田亮，等. AZ91D镁合金热变形行为及加工图研究
［J］. 特种铸造及有色合金, 2018, 38(4):453-457.

Qiu X D, Wang Z J, Tian L, et al. Hot deformation behavior and processing maps of as-cast AZ91D magnesium alloy
［J］. Special Casting and Nonferrous Alloys, 2018, 38(4):453-457.

［12］Wang Z, Wang X, Zhu Z S. Characterization of high-temperature deformation behavior and processing map of TB17 titanium alloy
［J］. Journal of Alloys and Compounds, 2017, 692:149-154.

［13］Meng Q G, Bai C G, Xu D S. Flow behavior and processing map for hot deformation of ATI425 titanium alloy
［J］. Journal of Materials Science & Technology, 2018, 34(4):679-688.

［14］Ren F C, Chen F, Chen J, et al. Hot deformation behavior and processing maps of AISI 420 martensitic stainless steel
［J］. Journal of Manufacturing Processes, 2018, 31:640-649.

［15］Sivakesavam O, Prasad Y V R K. Hot deformation behaviour of as-cast Mg-2Zn-1Mn alloy in compression: A study with processing map
［J］. Materials Science and Engineering A, 2003, 362(1-2):118-124.

［16］Ziegler H, Sneddon I N, Hill R, et al. Progress in Solid Mechanics
［M］. Amsterdam: North-Hoddand Publishing, 1985.

［17］Prasad Y V R K. Processing maps: A status report
［J］. Journal of Engineering and Performance, 2003, 12（6）: 638-645.

服务与反馈：

【文章下载】【加入收藏】