|
|
|
| Influence of N/C ratio on microstructure and properties of new high-strength weathering steels |
| Jian Cheng1,2 Yue-hua Guo3 Ming Liu3 Hou-fa Shen2 |
| 1 The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China 2 Key Laboratory for Advanced Materials Processing Technology, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China 3 Pangang Group Research Institute Co., Ltd., State Key Laboratory of Vanadium and Titanium Comprehensive Utilization, Panzhihua 617000, Sichuan, China |
|
|
|
|
Abstract Influence of the N/C ratio on the microstructure and properties of new-generation high-strength weathering steels was investigated using calculation of phase diagram (CALPHAD) and experiments. The microstructures of weathering steels containing different N/C ratios were predicted by a CALPHAD approach, and only three phases were predicted in these steels within the rolling temperature range of 850–1050 C. The precipitation fraction of VN/V(C, N) increases with increasing N/C ratio. Microstructures of the four tested steels were all experimentally determined to contain bainite, ferrite, and VN precipitates after air cooling to room temperature. The bainite fraction increases with increasing N/C ratio, and it is 85% in the steel containing 0.038% N and 0.032% C. The results of the tensile tests and impact tests demonstrated that the yield strength and tensile strength of the steel containing 0.038% N and 0.032% C are greater than 550 and 650 MPa, respectively, and the elongation is greater than 24%, which satisfies the design objectives for mechanical properties. The impact toughness values of the four steels at 0, - 20, and - 40 C are all greater than 24 J. With increasing N/C ratio, the bainite fraction and the precipitation fraction of VN/V(C, N) increase, resulting in increasing yield strength and tensile strength.
|
|
|
|
|
|
| Cite this article: |
|
Jian Cheng,Yue-hua Guo,Ming Liu, et al. Influence of N/C ratio on microstructure and properties of new high-strength weathering steels[J]. Journal of Iron and Steel Research International, 2019, 26(1): 84-90.
|
|
|
|
| [1] |
Wen-gang Bu, Wei Zhang, Jin-liang Gao, Yan Qi, Dong-liang Zhao, Xiao-ping Dong, Yang-huan Zhang. Structure and electrochemical performances of as-milled LaMg12-type alloy–Ni composites[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2019, 26(1): 59-68. |
| [2] |
He Wei, Yin-li Chen, Lan Su, Di Tang. Effect of simulated thermomechanical processing on transformation behavior and microstructure of 82B steel[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2019, 26(1): 69-77. |
| [3] |
Jin-biao Zhou, Peng-yan Sun, Chang-yu Zhou, Xiao-hua He. Experimental characterization of anisotropic tensile mechanical behavior of pure titanium tube[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2019, 26(1): 91-101. |
| [4] |
Xi-yang Chai, . Tao Pan . Feng Chai . Xiao-bing Luo . Hang Su . Zhi-gang Yang . Cai-fu Yang. Interlayer engineering for titanium clad steel by hot roll bonding[J]. , 2018, 25(7): 739-745. |
| [5] |
Shuai Xu . Zhang-jian Zhou . Shao-fu Li . Hao-dong Jia. Long-term thermal-aging stability of oxide-dispersion-strengthened ferritic steels at 753 K[J]. , 2018, 25(7): 753-784. |
| [6] |
Jun Jiang,. Hua Ding . Zong-an Luo . Guang-ming Xie. Interfacial microstructure and mechanical properties of stainless steel clad plate prepared by vacuum hot rolling[J]. , 2018, 25(7): 732-738. |
|
|
|
|
2019, Vol. 26 
