The Effects of Prior Austenite Grain Refinement on Strength and Toughness of High-Strength Low-Alloy Steel
<p>Band contrast map (<b>a</b>–<b>c</b>) and inverse pole figure color map (<b>d</b>–<b>f</b>) of three experimental samples: (<b>a</b>) and (<b>d</b>) Q850, (<b>b</b>) and (<b>e</b>) Q950, (<b>c</b>) and (<b>f</b>) Q1050.</p> "> Figure 2
<p>The density of HAGBs in three experimental samples.</p> "> Figure 3
<p>Different types of boundaries (black lines: PAG boundaries, blue lines: packet boundaries, red lines: block boundaries, green lines: sub-block boundaries) of (<b>a</b>) Q850, (<b>b</b>) Q950 and (<b>c</b>) Q1050.</p> "> Figure 4
<p>Comparison of density according to different grain boundary type.</p> "> Figure 5
<p>PAG boundary map of three experimental samples: (<b>a</b>) Q850, (<b>b</b>) Q950 and (<b>c</b>) Q1050.</p> "> Figure 6
<p>Charpy impact energy of experimental samples: (<b>a</b>) Q850, (<b>b</b>) Q950 and (<b>c</b>) Q1050.</p> "> Figure 7
<p>Morphology of fracture surface of Q950 impact tested specimen. (<b>a</b>) overall macro-morphology of fracture surface, (<b>b</b>) micro-morphology of fracture surface close to the notch, (<b>c</b>) micro-morphology of fracture surface at the center.</p> "> Figure 8
<p>Morphology of fracture surface of Q1050 impact tested specimen. (<b>a</b>) overall macro-morphology of fracture surface, (<b>b</b>) micro-morphology of fracture surface close to the notch, (<b>c</b>) micro-morphology of fracture surface at the center.</p> "> Figure 9
<p>Micro-morphology of fracture surface of three experimental samples impact tested at −120 °C: (<b>a</b>) Q850, (<b>b</b>) Q950 and (<b>c</b>) Q1050.</p> ">
Abstract
:1. Introduction
2. Materials and Methods
3. Results
4. Discussion
5. Conclusions
- The uniform refinement of prior austenite grain can increase the density of packet boundary and block boundary, so as to obtain a higher density of HAGBs and realize multi-level microstructure refinement.
- The contribution of this microstructure refinement formed by refining prior austenite grains to toughness is significant, but its contributions to strength and elongation is relatively limited.
- If the PAGs are mixed crystal, the new formed block boundaries are fewer, and the density of high angle boundary with misorientation >45° will be reduced.
- Mixed crystal PAGs weaken the positive effect of microstructure refinement on toughness improvement.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Samples | Yield Strength (MPa) | Tensile Strength (MPa) | Uniform Elongation (%) | Total Elongation (%) | Reduction (%) |
---|---|---|---|---|---|
Q850 | 934 ± 1 | 1280 ± 3 | 4.1 ± 0.1 | 14.9 ± 0.3 | 68 ± 2 |
Q950 | 893 ± 5 | 1243 ± 9 | 4.0 ± 0.1 | 14.5 ± 0.1 | 67 ± 2 |
Q1050 | 898 ± 7 | 1260 ± 1 | 3.9 ± 0.1 | 13.8 ± 0.2 | 67 ± 1 |
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Li, X.; Lu, G.; Wang, Q.; Zhao, J.; Xie, Z.; Misra, R.D.K.; Shang, C. The Effects of Prior Austenite Grain Refinement on Strength and Toughness of High-Strength Low-Alloy Steel. Metals 2022, 12, 28. https://doi.org/10.3390/met12010028
Li X, Lu G, Wang Q, Zhao J, Xie Z, Misra RDK, Shang C. The Effects of Prior Austenite Grain Refinement on Strength and Toughness of High-Strength Low-Alloy Steel. Metals. 2022; 12(1):28. https://doi.org/10.3390/met12010028
Chicago/Turabian StyleLi, Xiucheng, Guangyi Lu, Qichen Wang, Jingxiao Zhao, Zhenjia Xie, Raja Devesh Kumar Misra, and Chengjia Shang. 2022. "The Effects of Prior Austenite Grain Refinement on Strength and Toughness of High-Strength Low-Alloy Steel" Metals 12, no. 1: 28. https://doi.org/10.3390/met12010028