Formation Mechanism of MgO Containing Inclusions in the Molten Steel Refined in MgO Refractory Crucibles
Abstract
1. Introduction
2. Experimental Procedure
3. Variation of the Composition of Steel and Slag
4. Characteristics of Inclusions
5. Formation Mechanism of MgO-Containing Inclusions
6. Conclusions
- (1)
- In ultra-low Al ultra-low C steel ([Al] < 0.0010%, C < 0.0025%), there was no MgO-containing inclusions other than FeO formed.
- (2)
- In ultra-low Al high C steel ([Al] < 0.0010%, C > 0.5%), almost all inclusions were pure MgO. When the [Al] content in steel increased to larger than 0.0015%, inclusions were changed to spinel, some of which were rich in MgO.
- (3)
- In high Al low C steel ([Al] > 0.01%, C < 0.006%)—in the cases of slag-free and addition of MgO-free slag—inclusions were mainly MgO and MgO-rich spinel, while with the addition of 10% MgO contained slag, inclusions were almost pure MgO.
- (4)
- For both the low Al high C steel and the high Al low C steel, the order of MgO content from large to small was: slag B > slag A > slag-free. Based on the experimental results, a simple formation mechanism of MgO-containing inclusions in the steel with different compositions in MgO crucibles was proposed.
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Group | Heat no. | Slag (R = 7, 50 g) | Steel Preparation (around 100 g) |
---|---|---|---|
ULAULC | 1 | No slag | Electrolytic iron (EI) |
2 | Slag A | ||
3 | Slag B | ||
LAHC | 1 | No slag | 1 kg EI + 10 g C melted in Al2O3 crucible using VIF |
2 | Slag A | ||
3 | Slag B | ||
ULAHC | 1 | No slag | 1 kg EI melted in graphite crucible using VIF |
2 | Slag A | ||
3 | Slag B | ||
HALC | 1 | No slag | 1 kg EI + 10 g Al melted in Al2O3 crucible using VIF |
2 | Slag A | ||
3 | Slag B |
Element | C | Si | Mn | P | S | T.Al | T.Mg | T.O |
---|---|---|---|---|---|---|---|---|
Content | 0.0024 | <0.0005 | 0.0001 | 0.0004 | 0.0006 | 0.0018 | <0.0004 | 0.0105 |
Slag | CaO | SiO2 | Al2O3 | MgO |
---|---|---|---|---|
A | 48.1 | 6.9 | 45.0 | 0.0 |
B | 43.2 | 6.2 | 40.6 | 10.0 |
Group | No. | Slag | Steel Composition | Slag Composition after Experiment | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|
[Al] | T.Mg | C | T.O | CaO | Al2O3 | MgO | SiO2 | Fe2O3 | |||
ULAULC | 0 | 0.0008 | <0.0004 | 0.0024 | 0.0105 | ||||||
1 | none | <0.0005 | <0.0005 | - | 0.0060 | ||||||
2 | A | <0.0005 | <0.0005 | - | 0.0041 | 48.55 | 32.20 | 9.04 | 6.69 | 3.01 | |
3 | B | <0.0005 | 0.0005 | - | 0.0081 | 48.19 | 31.45 | 9.43 | 6.20 | 4.35 | |
LAHC | 0 | 0.0021 | <0.0004 | 0.84 | - | ||||||
1 | none | 0.0032 | 0.0068 | - | 0.0160 | ||||||
2 | A | 0.0016 | 0.0003 | 0.78 | 0.0123 | 50.45 | 33.40 | 7.46 | 6.64 | 1.62 | |
3 | B | 0.0075 | 0.0039 | - | 0.0106 | 47.97 | 33.60 | 9.91 | 6.33 | 1.73 | |
ULAHC | 0 | 0.0006 | <0.0004 | 4.37 | 0.0181 | ||||||
2 | A | 0.0012 | 0.0004 | 3.77 | 0.0167 | 50.61 | 33.78 | 9.09 | 6.52 | 1.86 | |
3 | B | 0.0012 | 0.0007 | 3.85 | 0.0133 | 50.52 | 33.67 | 9.54 | 6.27 | ||
HALC | 0 | 0.40 | <0.0004 | 0.0062 | - | ||||||
1 | none | 0.32 | 0.0010 | - | 0.00050 | ||||||
2 | A | 0.0096 | <0.0005 | - | 0.00044 | 50.31 | 33.26 | 8.16 | 5.61 | 1.73 | |
3 | B | 0.0110 | 0.0006 | - | 0.00043 | 48.52 | 34.49 | 9.81 | 5.14 | 1.58 |
Group | No. | Slag | Inclusion | |
---|---|---|---|---|
Morphology | Type | |||
ULAULC | 1 | none | FeO | |
2 | A | FeO | ||
3 | B | FeO | ||
LAHC | 1 | none | spinel | |
2 | A | spinel | ||
3 | B | spinel | ||
ULAHC | 2 | A | MgO | |
3 | B | MgO | ||
HALC | 1 | none | MgO + spinel | |
2 | A | MgO + spinel | ||
3 | B | MgO |
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Li, Y.; Yang, W.; Zhang, L. Formation Mechanism of MgO Containing Inclusions in the Molten Steel Refined in MgO Refractory Crucibles. Metals 2020, 10, 444. https://doi.org/10.3390/met10040444
Li Y, Yang W, Zhang L. Formation Mechanism of MgO Containing Inclusions in the Molten Steel Refined in MgO Refractory Crucibles. Metals. 2020; 10(4):444. https://doi.org/10.3390/met10040444
Chicago/Turabian StyleLi, Yiyan, Wen Yang, and Lifeng Zhang. 2020. "Formation Mechanism of MgO Containing Inclusions in the Molten Steel Refined in MgO Refractory Crucibles" Metals 10, no. 4: 444. https://doi.org/10.3390/met10040444
APA StyleLi, Y., Yang, W., & Zhang, L. (2020). Formation Mechanism of MgO Containing Inclusions in the Molten Steel Refined in MgO Refractory Crucibles. Metals, 10(4), 444. https://doi.org/10.3390/met10040444