| 引用本文: | 宋仁伯,李佳佳,李轩,周乃鹏,王莉.Fe-8Mn-3Al-0.2C轻质高强钢的热变形行为[J].材料科学与工艺,2018,26(1):81-87.DOI:10.11951/j.issn.1005-0299.20170229. |
| SONG Renbo,LI Jiajia,LI Xuan,ZHOU Naipeng,WANG Li.Hot deformation behavior of Fe-8Mn-3Al-0.2C steel[J].Materials Science and Technology,2018,26(1):81-87.DOI:10.11951/j.issn.1005-0299.20170229. |
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| 摘要: |
| 为了探究Fe-8Mn-3Al-0.2C轻质高强钢的热变形行为，在变形温度为1 123~1 423 K，应变速率0.01, 0.1, 1, 10 s-1，真应变为0.6的条件下利用Gleeble-1500热模拟实验机进行热压缩模拟实验，通过实验机记录温度、真应力与真应变的关系，观察组织形貌演变规律.结果表明：流变应力曲线分为3个阶段，即加工硬化、动态软化及稳定流变应力；当变形温度升高和应变速率下降时，峰值应力及其所对应的临界应变减小，说明更容易发生动态再结晶；在变形初期ε < 0.1时，流变应力曲线出现应变增加而应力几乎保持不变的类屈服平台；压缩后的组织为奥氏体/铁素体双相组织，动态再结晶先在铁素体内部发生，随后由奥氏体承担；随着变形温度的升高和应变速率的下降，晶粒尺寸细化并趋于均匀，说明动态再结晶完成的更充分；本实验钢在本文处理工艺及0.6真应变下的最佳热加工工艺参数区间为1 250~1 400 K，应变速率为0.03~0.3 s-1；受合金元素影响，实验用钢的表观应力指数和热变形激活能分别为4.588 9和250.6 kJ/mol，本构方程为$\dot \varepsilon = 6.20 \times {10^9}{[{\rm{sinh(0}}{\rm{.009}}\sigma {\rm{)}}]^{4.588\;9}}\exp \left( { - \frac{{250\;601}}{{8.314T}}} \right)$
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| 关键词: Fe-Mn-Al-C钢 热变形 动态再结晶 本构方程 热加工图 |
| DOI：10.11951/j.issn.1005-0299.20170229 |
| 分类号:TG142.1 |
| 文献标识码:A |
| 基金项目: |
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| Hot deformation behavior of Fe-8Mn-3Al-0.2C steel |
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SONG Renbo1,LI Jiajia1,LI Xuan1,ZHOU Naipeng1,WANG Li2
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(1.School of Materials Science Engineering, University of Science and Technology Beijing, Beijing 100083, China; 2.School of Electronics and Information Engineering, Liaoning University of Science and Technology, Anshan 114051,China)
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| Abstract: |
| In the present research, the hot deformation behavior of Fe-8Mn-3Al-0.2C steel was investigated by uniaxial compression test using Gleeble-1500 thermal-mechanical simulator within the temperature range of 1 123~1 423 K and the strain rate range of 0.01~10 s-1. The flow curves could be divided into three stages: work hardening, dynamic softening and stress steady. As temperature increased and strain rate decreased, the peak stress and critical strain decreased, implying that the dynamic recrystallization was easier to occur. At the initial stage of ε < 0.1, the yield-like platform at which the flow stresses keep constant with the increase of strain will appear in the flow stress curves. The microstructure after compressed was austenite and ferrite dual structure. The dynamic recrystallization occurred first in the ferrite, followed by the austenite. As deformation temperature increased and strain rate decreased, the grain refinement was uniform and the dynamic recrystallization was completed.The hot processing map showed that the optimum hot processing area was the temperature range of 1 250~1 400 K and strain rate range of 0.03~0.3 s-1. The apparent activation energy (Q) and the stress exponent (n) were 250.64 kJ/mol and 4.588 9, respectively after calculation, so constitutive equation for hot deformation could be described as $\dot \varepsilon = 6.20 \times {10^9}{[{\rm{sinh(0}}{\rm{.009}}\sigma {\rm{)}}]^{4.588\;9}}\exp \left( { - \frac{{250\;601}}{{8.314T}}} \right)$
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| Key words: Fe-Mn-Al-C steel hot deformation dynamic recrystallization constitutive equation hot processing map |
