Tensile Behavior, Constitutive Model, and Deformation Mechanisms of MarBN Steel at Various Temperatures and Strain Rates

Yifan Cai; Quanyi Wang; Meng Liu; Yunqing Jiang; Tongfei Zou; Yunru Wang; Qingsong Li; Yubing Pei; Hong Zhang; Yongjie Liu; Qingyuan Wang

doi:10.3390/ma15248745

Tensile Behavior, Constitutive Model, and Deformation Mechanisms of MarBN Steel at Various Temperatures and Strain Rates

Materials (Basel). 2022 Dec 7;15(24):8745. doi: 10.3390/ma15248745.

Authors

Yifan Cai^{1

2}, Quanyi Wang^{1

2}, Meng Liu^{1

2}, Yunqing Jiang^{1

2}, Tongfei Zou^{1

2}, Yunru Wang^{1

2}, Qingsong Li³, Yubing Pei³, Hong Zhang^{1

2

3}, Yongjie Liu^{1

2}, Qingyuan Wang^{1

2

4}

Affiliations

¹ Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
² Key Laboratory of Deep Underground Science and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China.
³ State Key Laboratory of Long-Life High Temperature Materials, Dongfang Turbine Co., Ltd., Deyang 618000, China.
⁴ School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China.

Abstract

To reduce harmful gas emission and improve the operational efficiency, advanced ultra-supercritical power plants put forward higher requirements on the high temperature mechanical properties of applied materials. In this paper, the tensile behavior and deformation mechanisms of MarBN steel are discussed at different strain rates (5 × 10^-3 s^-1, 5 × 10^-4 s^-1, and 5 × 10^-5 s^-1) under room temperature and 630 °C. The results show that the tensile behavior of the alloy is dependent on temperature and strain rate, which derived from the balance between the average dislocation velocity and dislocation density. Furthermore, observed dynamic recrystallized grains under severe deformation reveal the existence of dynamic recovery at 630 °C, which increases the elongation compared to room temperature. Finally, three typical constitutive equations are used to quantitatively describe the tensile deformation behavior of MarBN steel under different strain rates and temperatures. Meanwhile, the constitutive model of flow stress for MarBN steel is developed based on the hyperbolic sine law.

Keywords: MarBN steel; constitutive model; deformation mechanism; microstructure; tensile behavior.

Grants and funding

The work was supported by the National Natural Science Research Funds of China (No. 12272245, No. 11832007, No.12172238), the National Postdoctoral funds of China (No. 2019M653396), the National Key R & D Program (No. 2018YFE0307104), the Applied Basic Research Programs of Sichuan Province (No. 2022NSFSC0324), the Sichuan University and ZiGong Government Support Program (No. 2019CDZG-4), and the International Visiting Program for Excellent Young Scholars of SCU. The authors are sincerely grateful and supported by the fund of the State Key Laboratory of Long-Life High-Temperature Materials (No. DECSKL202102). The authors thank Yan Li for performing the experiments and Weihua Guo for performing the microstructure tests.