锻压技术

DP780双相钢在不同应变状态下的断裂特性及机理

英文标题：Fracture characteristics and mechanism on DP780 dual-phase steel under different strain states

作者：余立刘静葛锐魏星彭周陈明刘冬

关键词：DP780双相钢应变状态断裂失效等效塑性断裂应变极限减薄率相界面应力集中

分类号：TG386

出版年,卷(期):页码：2022,47(10):48-55

摘要：

先进高强钢（AHSS）是重要的汽车轻量化材料，其在不同应变状态下会表现出不同的断裂特性。以DP780双相钢为研究对象，研究了其在典型应变状态下的断裂失效行为，并对试样的微观组织和断口形貌进行了观察和表征，分析了DP780双相钢在不同应变状态下断裂的微观机理。研究表明：随着应变比的提高，等效塑性断裂应变ε-f先减小后增大；平面应变状态下ε-f最小，等轴拉伸应变状态下ε-f最大。应变状态对DP780双相钢的断裂特性和失效有重要影响：平面应变状态下，试样芯部的厚向应变梯度和三向拉应力状态增加了变形的不协调程度，加速了微孔洞的萌生和生长，相对于单轴拉伸更容易产生厚向裂纹而发生撕裂；等轴拉伸应变状态下，材料变形均匀，厚向应变梯度小，孔洞的萌生和生长受到抑制，从而使DP780双相钢在等轴拉伸应变状态下的等效塑性断裂应变最大。

Advanced high strength steel (AHSS) is an important material for lightweight in automobile, which performs different fracture characteristics under different strain states. Therefore, for DP780 dual-phase steel, the fracture failure behavior under typical strain state was studied. Then, the microstructure and fracture morphology of samples were observed and characterized, and the fracture micro-mechanism of DP780 dual-phase steel under different strain states was analyzed. The results show that with the increasing of strain ratio, the equivalent plastic fracture strain εf decreases first and then increases, εf is the smallest under plane strain state. And the largest under equiaxial tension strain state. And the strain state has a significant effect on the fracture characteristics and failure of DP780 dual-phase steel. Under the plane strain state, the strain gradient along the thickness direction and the triaxial tensile stress state in the material core increase the inconsistency degree of deformation, accelerate the initiation and growth of micro-voids, and are more likely to produce cracks along the thickness direction and tear compared with the uniaxial tensile state. Under the equiaxial tension strain state, the material deforms uniformly, the stain gradient along the thickness direction is small, and the initiation and growth of pores are inhibited so that the equivalent plastic fracture strain of DP780 dual-phase steel under the equiaxial tensile strain state is the largest.

基金项目：

国家自然科学基金资助项目（U20A20270）

余立（1984-），男，博士研究生，高级工程师,E-mail：yu.li@baosteel.com;通信作者：刘静（1964-），女，博士，教授,E-mail：liujing@wust.edu.cn

参考文献：

[1]马鸣图. 先进汽车用钢[M]. 北京: 化学工业出版社, 2008.

Ma M T. Advanced Automotive Steel [M]. Beijing: Chemical Industry Press, 2008.

[2]李光瀛, 王利, 马鸣图,等. 第3代先进高强度钢AHSS汽车板的开发[J]. 轧钢, 2019, 36(5): 1-13.

Li G Y, Wang L, Ma M T, et al. Development of 3rd generation advanced high strength steel for automobile[J]. Steel Rolling, 2019, 36(5): 1-13.

[3]刘清梅，封娇洁. 汽车轻量化条件下先进高强钢的发展及现状[J]. 轧钢, 2020, 37(4): 65-70,90.

Liu Q M, Feng J J. Development and current situation of advanced highstrength steel under the condition of automotive light weight[J]. Steel Rolling, 2020, 37(4): 65-70,90.

[4]金学军, 龚煜, 韩先洪,等. 先进热成形汽车钢制造与使用的研究现状与展望[J]. 金属学报, 2020, 56(4): 411-428.

Jing X J, Gong Y, Han X H, et al. A review of current state and prospect of the manufacturing and application of advanced hot stamping automobile steels[J]. Acta Metallurgica Sinica, 2020, 56(4): 411-428.

[5]路洪洲, 王智文, 陈一龙. 汽车轻量化评价[J]. 汽车工程学报, 2015, 5(1): 1-8.

Lu H Z, Wang Z W, Chen Y L. Evaluation methodology for automotive lightweight design[J]. Chinese Journal of Automotive Engineering, 2015, 5(1): 1-8.

[6]Keeler S, Kimchi M. Advanced Highstrength Steels Application Guidelines V6[M]. Brussels: World Auto Steel, 2018.

[7]Hu Q, Zhang F, Li X, et al. Overview on the prediction models for sheet metal forming failure: Necking and ductile fracture[J]. Acta Mechanica Solida Sinica, 2018, 31(3): 259-289.

[8]Park N, Huh H, Lim S J, et al. Fracturebased forming limit criteria for anisotropic materials in sheet metal forming[J]. International Journal of Plasticity, 2017, 96: 1-35.

[9]Barnwal V K, Lee S Y, Choi J, et al. Fracture assessment in dual phase and transformationinduced plasticity steels during 3-point bending[J]. Theoretical and Applied Fracture Mechanics, 2020, 110: 1-16.

[10]Barrett T J, Knezevic M. Modeling material behavior during continuous bending under tension for inferring the postnecking strain hardening response of ductile sheet metals: Application to DP780 steel[J]. International Journal of Mechanical Sciences, 2020, 174105508.

[11]潘利波, 左治江, 周文强,等. 双相钢的成形与断裂极限性能分析[J]. 锻压技术, 2021, 46(7): 185-189.

Pan L B, Zuo Z J, Zhou W Q, et at. Analysis on forming and fracture limit properties for dual phase steel[J]. Forging & Stamping Technology, 2021, 46(7): 185-189.

[12]Bao Y, Wierzbicki T. On fracture locus in the equivalent strain and stress triaxiality space[J]. International Journal of Mechanical Sciences, 2004, 46(1): 81-98.

[13]Bao Y, Wierzbicki T. On the cutoff value of negative triaxiality for fracture[J]. Engineering Fracture Mechanics, 2005, 72(7): 1049-1069.

[14]Bai Y, Wierzbicki T. A new model of metal plasticity and fracture with pressure and Lode dependence[J]. International Journal of Plasticity, 2008, 24(6): 1071-1096.

[15]Bai Y, Wierzbicki T. Application of extended mohr-coulomb criterion to ductile fracture[J]. International Journal of Fracture, 2010, 161(1): 1-10.

[16]Lou Y S, Huh H, Lim S, et al. New ductile fracture criterion for prediction of fracture forming limit diagrams of sheet metals[J]. International Journal of Solids and Structures, 2012, 49(25): 3605-3615.

[17]Lou Y S, Lim S J, Huh H. Prediction of fracture forming limit for DP780 steel sheet[J]. Metals and Materials International, 2013, 19(4): 697-705.

[18]Cheng C, Meng B, Han J Q, et al. A modified LouHuh model for characterization of ductile fracture of DP590 sheet[J]. Materials & Design, 2017, 118: 89-98.

[19]Samei J, Green D E, Cheng J, et al. Influence of strain path on nucleation and growth of voids in dual phase steel sheets[J]. Materials & Design, 2016, 92: 1028-1037.

[20]ISO 12004—2:2021,Metallic materials—Determination of forminglimit curves for sheet and strip—Part 2: Determination of forming-limit curves in the laboratory[S].

[21]Nikhare C, Hodgson P D, Weiss M. Necking and fracture of advanced high strength steels[J]. Materials Science and Engineering: A, 2011, 528(6): 3010-3013.

[22]王平, 崔建忠. 金属塑性成形力学[M]. 北京: 冶金工业出版社, 2018.

Wang P, Cui J Z. Mechanics of Metal Plastic Forming [M]. Beijing: Metallurgical Industry Press, 2018.

[23]王自强, 段祝平. 塑性细观力学[M]. 北京: 科学出版社, 1995.

Wang Z Q, Duan Z P. Micromechanics of Plasticity [M]. Beijing: Science Press, 1995.

[24]Ashrafi H, Shamanian M, Emadi R, et al. Void formation and plastic deformation mechanism of a coldrolled dualphase steel during tension[J]. Acta Metallurgica Sinica (English Letters), 2020, 33: 299-36.

[25]夏志皋. 塑性力学[M]. 上海: 同济大学出版社, 1991.

Xia Z G. Plastic Mechanics [M]. Shanghai: Tongji University Press, 1991.

[26]Frómeta D, Lara A, Grifé L, et al. Fracture resistance of advanced highstrength steel sheets for automotive applications[J]. Metallurgical and Materials Transactions A, 2021, 52(2): 840-856.

服务与反馈：

【文章下载】【加入收藏】