|
|
|
| Microstructure and properties evolution of Nb-bearing medium Cr wear-resistant cast steel during heat treatment |
| Jia-cheng Zhang1, Tuo Zhang1, Yi-tao Yang1 |
| 1 School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China |
|
|
|
|
Abstract The effect of quenching temperature and cooling conditions on the microstructure and mechanical properties of a 0.2%Nb medium chromium wear-resistant cast steel was investigated. The microstructure, carbides and volume fraction of retained austenite were characterized using the optical microscope, scanning electron microscope, transmission electron microscope and X-ray diffraction. The influence of heat treatment on hardness, impact toughness and tensile properties of test steel was studied. It can be observed that lath martensite can be obtained under the condition of air cooling and oil cooling upon austenitizing in the range of 900–1020 °C. Total carbide content of 0.2–1.1 wt.% under air cooling is more than that under oil cooling due to the lower cooling rate. Nb6C5, M23C6 and M7C3 were found at lower austenitizing temperature, of which niobium carbide mostly located at grain boundaries, while chromium carbides were uniformly distributed in the matrix with the size of 20–50 nm. The chromium carbides are basically dissolved into the matrix in test steel austenitized at 1020 °C. Meanwhile, the negligible growth of prior austenite grain size is achieved. Specimen austenitized at 1020 °C and cooled in air + tempered at 200 °C has a best combination of hardness, plasticity and tensile strength due to fine grain size and more amount of retained austenite. Under this condition, the hardness is 58 HRC, the impact toughness is 22.92 J/cm2, and the tensile strength is 1136.9 MPa.
|
|
|
|
|
|
| Cite this article: |
|
Jia-cheng Zhang,Tuo Zhang,Yi-tao Yang. Microstructure and properties evolution of Nb-bearing medium Cr wear-resistant cast steel during heat treatment[J]. Journal of Iron and Steel Research International, 2021, 28(06): 739-751.
|
|
|
|
| [1] |
Fei Zhu, Feng Chai, Xiao-bing Luo, Zheng-yan Zhang, Cai-fu Yang. Strengthening and toughening mechanism of a Cu-bearing highstrength low-alloy steel with refined tempered martensite/bainite (M/ B) matrix and minor inter-critical ferrite[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2021, 28(4): 464-478. |
| [2] |
Yu‑lu Li, Yue Zhao, Lin Shen, Hao Wu, He‑guo Zhu. Microstructure and mechanical properties of in situ (TiC + SiC)/FeCrCoNi high entropy alloy matrix composites[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2021, 28(4): 496-504. |
| [3] |
Chen‑chong Wang, Chun‑guang Shen, Zhen Zhang, Wei Xu. Simulation and verification of core–shell MC carbide design in Fe–C–Ni–V–Ti steel[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2021, 28(1): 58-65. |
| [4] |
Guang‑di Zhao, Xi‑min Zang, Wen‑ru Sun. Role of carbon in modifying solidification and microstructure of a Ni?based superalloy with high Al and Ti contents[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2021, 28(1): 98-110. |
| [5] |
Xiang‑dong Huo, Kang He, Ji‑nian Xia, Lie‑jun Li, Song‑jun Chen. Isothermal transformation and precipitation behaviors of titanium microalloyed steels[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2021, 28(03): 335-345. |
| [6] |
Chang-sheng Li, Bin-zhou Li, Xin Jin, Yu Wang. Microstructure and mechanical properties in core of a carburizing 20CrNi2MoV bearing steel subjected to cryogenic treatment[J]. JOURNAL OF IRON AND STEEL RESEARCH,INTERNATIONAL, 2021, 28(03): 360-369. |
|
|
|
|
2021, Vol. 28 
