锻压技术

EA4T车轴钢高温拉伸变形行为及塑性损伤演变规律

英文标题：Tensile deformation behavior and plastic damage evolution law of EA4T axle steel at high temperature

作者：卞志远霍元明何涛白杰任旭杜向阳

单位：上海工程技术大学

分类号：TG115.21

出版年,卷(期):页码：2023,48(2):224-232

摘要：

为了研究EA4T车轴钢在高温拉伸时的力学性能、微观组织和塑性损伤演变规律,在Gleeble-3800热模拟试验机上进行了光滑圆棒和缺口圆棒的高温拉伸试验，试验温度为970、1070和1170 ℃，应变速率为0.1、1.0和10.0 s-1，缺口半径分别为15、10和5 mm的缺口圆棒试样对应不同的应力三轴度。结果表明：EA4T车轴钢在高温变形中，断裂应变随着温度的升高而降低，随着应变速率的增大而增大。随着应力三轴度的增大，平均断裂应变呈降低趋势，微观组织中微孔洞的数量更多、尺寸更大。动态再结晶过程会阻碍微孔洞的长大和汇聚，随着再结晶程度的加深，孔洞由宽大椭圆形变为细长梭形，平均尺寸减小，孔洞的拉长方向指向断面收缩的中心，拉长的孔洞使断面形成了较深的等轴韧窝。

In order to study the mechanical properties, microstructure and plastic damage evolution law of EA4T axle steel during high temperature tensile, the high temperature tensile tests of smooth and notched round bars were carried out on the thermal simulation test machine Gleeble-3800. The test temperature was 970, 1070 and 1170 ℃, the strain rates was 0.1, 1.0 and 10.0 s-1, and the notched round bar samples with the notched radius of 15, 10 and 5 mm respectively had different stress triaxialities. The results show that the fracture strain of EA4T axle steel decreases with the increasing of temperature and increases with the increasing of strain rate during high temperature deformation. With the increasing of stress triaxiality, the average fracture strain shows a decreasing trend, and the number and size of microvoids in the microstructure are larger. The dynamic recrystallization process hinders the growth and aggregation of microvoids. As the degree of recrystallization deepens, the microvoids change from wide oval to slender shuttle, and the average size decreases, and the elongation direction of the microvoids points to the center of the section shrinkage. Thus, the elongated microvoids cause the section to form a deep equiaxed dimple.

基金项目：

国家重点研发计划资助（2018YFB1307900）

作者简介：卞志远（1997-），男，硕士研究生，E-mail：bian_zhiyuan2020@163.com；通信作者：霍元明（1984-），男，博士，副教授，E-mail：yuanming.huo@sues.edu.cn

参考文献：

[1]王之香，王玉玲，国产与进口EA4T车轴材料性能对比研究[J].山西冶金，2017，40(1)：1-2，10.

Wang Z X，Wang Y L.Comparison research of performance with domestic and imported EA4T axle material [J].Shanxi Metallurgy，2017，40(1)：1-2，10.

[2]Xu G，Wang L N，Li S Q，et al.Hot deformation behavior of EA4T steel[J].Acta Metallurgica Sinica:English Letters，2012，25(5)：374-382.

[3]杨千华，薛春，楚志兵，等.大型轴类楔横轧装备结构优化设计[J].重型机械，2021，(6):74-80.

Yang Q H,，Xue C，Chu Z B,et al.Structural optimization design of large shaft cross wedge rolling equipment [J].Heavy Machinery，2021，(6)：74-80.

[4]Li C Y，Dai W B， Zhang H Z，et al.Effect of initial forging temperature on mechanical properties and fatigue behavior of EA4T steel[J].Engineering Fracture Mechanics，2020，238:107287.

[5]徐刚，李士琦，王乐，等.高铁用EA4T车轴钢热变形行为及变形抗力模型的试验研究[J].特殊钢，2013，34(3)：60-63.

Xu G，Li S Q，Wang L，et al.Experimental study on hot deformation behavior and math models for deformation resistance of EA4T axle steel for high speed rail[J]. Special Steel， 2013，34(3)：60-63.

[6]黄昌虎，宋新莉，贾涓，等.拉伸温度对Cr18Ni10Ti不锈钢力学性能影响[J].材料热处理学报，2021，42(9)：112-118.

Huang C H，Song X L，Jia J，et al.Effect of tensile temperature on mechanical properties of Cr18Ni10Ti stainless steel [J].Transactions of Materials and Heat Treatment， 2021，42(9)：112-118.

[7]贾昌远，霍元明，何涛，等.40CrNiMo钢高温拉伸变形行为和组织演变规律[J].金属热处理，2022，47(4)：69-74.

Jia C Y，Huo Y M，He T，et al. High temperature tensile deformation behavior and microstructure evolution law of 40 CrNiMo steel[J].Heat Treatment of Metals,2022，47(4)：69-74.

[8]张丁非，戴庆伟，胡耀波，等.塑性损伤的发展与应用[J].材料工程，2011,(1)：92-98.

Zhang D F，Dai Q W，Hu Y B，et al.Development and application of ductile damage [J].Journal of Materials Engineering，2011,(1)：92-98.

[9]曹方，杨卯生，杨树峰，等.高氮不锈轴承钢碳化物分布与高温断裂机制[J].钢铁,2022,(6):132-142.

Cao F，Yang M S，Yang S F，et al.Carbide distribution and high-temperature fracture mechanism of high nitrogen stainless bearing steel [J]. Iron and Steel,2022,(6):132-142.

[10]尚晓晴. 316LN钢空洞损伤的微观机理与热变形断裂准则的研究[D].上海：上海交通大学，2019.

Shang X Q.Research on the Micro-mechanics of Void Damage and the Modeling of Ductile Fracture for Hot Deformation of the 316LN Steel [D].Shanghai：Shanghai Jiao Tong University，2019.

[11]王敏婷，李学通，张祥玉，等.EA4T钢热变形行为及组织演变规律研究[J].塑性工程学报，2018，25(1)：224-232.

Wang M T，Li X T，Zhang X Y，et al.Investigation on hot deformation behavior and microstructure evolution of EA4T steel [J].Journal of Plasticity Engineering，2018，25 (1)：224-232.

[12]霍元明，王宝雨，林建国，等.楔横轧高铁车轴钢25CrMo4塑性损伤形成机理 [J].东北大学学报：自然科学版，2013，34(11)：1625-1629.

Huo Y M，Wang B Y，Lin J G，et al.Damage mechanisms research for the high-speed railway axle steel 25CrMo4 during hot cross wedge rolling[J].Journal of Northeastern University:Natural Science，2013，34(11)：1625-1629.

[13]Fu J，Zhang Y S.Mechanism of crack initiation and propagation of 316LN stainless steel during the high temperature tensile deformation[J].Materials Research Express，2020，7(8)：085801.

[14]Shang X Q，Cui Z S，Fu M W.Dynamic recrystallization based ductile fracture modeling in hot working of metallic materials [J].International Journal of Plasticity，2017，95：105-122.

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