|
|
Prediction and Experimental Validation of Forming Limit Curve of a Quenched and Partitioned Steel |
Xue-li GAO1,Jun-ying MIN2,Ling ZHANG1,Quan-chao LI1,Chang-wei LIAN1,3,Jian-ping LIN1 |
1. School of Mechanical Engineering, Tongji University, Shanghai 201804, China 2. Chair of Production Systems,Ruhr-University Bochum, Bochum 44801, Germany 3. State Key Laboratory of Development and Application Technology of Automotive Steels Baosteel, Shanghai 201900, China |
|
|
Abstract Forming limit curve (FLC) is an effective tool to evaluate the formability of sheet metals. An accurate FLC prediction for a sheet metal is beneficial to its engineering application. A quenched and partitioned steel, known as QP980, is one of the 3rd generation advanced high strength steels and is composed of martensite, ferrite and a considerable amount of retained austenite (RA). Martensite transformation from RA induced by deformation, namely, transformation induced plasticity (TRIP), promotes the capability of work hardening and consequently formability. Nakazima tests were carried out to obtain the experimental forming limit strains with the aid of digital image correlation techniques. Scanning electron microscopy (SEM) was employed to examine the fracture morphologies of Nakazima specimens of the QP980 steel. The observed dimple pattern indicated that tensile stress was the predominant factor which led to failure of QP980 specimens. Therefore, maximum tensile stress criterion (MTSC) was adopted as the forming limit criterion. To predict the FLC of QP980 steel, Von-Mises yield criterion and power hardening law were adopted according to the tested mechanical properties of QP980 steel. Results were compared with those derived from other three representative instability theories, e.g. Hill criterion, Storen-Rice vertex theory and Bressan-Williams model, which shows that the MTSC based FLC is in better agreement with the experimental results.
|
Received: 25 May 2015
Published: 12 June 2016
|
Fund:�ߵ�ѧУ��ʿѧ�Ƶ�ר����л��� |
Corresponding Authors:
Jianping Lin
E-mail: jplin58@tongji.edu.cn
|
|
|
|
[1] |
Qiu-lin Niu,,Wei-wei Ming,Ming Chen,Si-wen Tang,,Peng-nan Li,. Dynamic mechanical behavior of ultra-high strength steel 30CrMnSiNi2A at high strain rates and elevated temperatures[J]. Chinese Journal of Iron and Steel, 2017, 24(7): 724-729. |
[2] |
Shu-lin Tan,Kun Yang,,Ya-nan Ding,Xian-hong Han,,*. Fracture morphologies of a hot stamped steel and comparisons with several sheet metals[J]. Chinese Journal of Iron and Steel, 2017, 24(6): 634-640. |
[3] |
Xuan-wei Lei,Ji-hua Huang*,Shu-hai Chen,Xing-ke Zhao. New bainite kinetics of high strength low alloy steel in fast cooling process[J]. Chinese Journal of Iron and Steel, 2017, 24(2): 229-233. |
[4] |
Meng-xuan Guo,Kai-xiang Gao,Wu-rong Wang,Xi-cheng Wei. Microstructural evolution of Al-Si coating and its influence on high tempera-ture tribological behavior of ultra-high strength steel against H13 steel[J]. Chinese Journal of Iron and Steel, 2017, 24(10): 1048-1058. |
[5] |
Zhen-xue Shi,Shi-zhong Liu,Xiao-dai Yue,Li-jie Hu,Wan-peng Yang,Xiao-guang Wang,Jia-rong Li. Effect of cellular recrystallization on tensile properties of a nickel-based single crystal superalloy containing Re and Ru[J]. Chinese Journal of Iron and Steel, 2017, 24(10): 1059-1064. |
[6] |
Jian KANG,Cheng-ning LI,Xiao-lei LI,,Jin-hua ZHAO,Guo YUAN,Guo-dong WANG. Effects of Processing Variables on Microstructure and Yield Ratio of High Strength Constructional Steels[J]. Chinese Journal of Iron and Steel, 2016, 23(8): 815-821. |
|
|
|
|