1
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Réant BL, Mackintosh FJ, Gransbury GK, Mattei CA, Alnami B, Atkinson BE, Bonham KL, Baldwin J, Wooles AJ, Vitorica-Yrezabal IJ, Lee D, Chilton NF, Liddle ST, Mills DP. Tris-Silanide f-Block Complexes: Insights into Paramagnetic Influence on NMR Chemical Shifts. JACS AU 2024; 4:2695-2711. [PMID: 39055148 PMCID: PMC11267535 DOI: 10.1021/jacsau.4c00466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/25/2024] [Accepted: 06/26/2024] [Indexed: 07/27/2024]
Abstract
The paramagnetism of f-block ions has been exploited in chiral shift reagents and magnetic resonance imaging, but these applications tend to focus on 1H NMR shifts as paramagnetic broadening makes less sensitive nuclei more difficult to study. Here we report a solution and solid-state (ss) 29Si NMR study of an isostructural series of locally D 3h -symmetric early f-block metal(III) tris-hypersilanide complexes, [M{Si(SiMe3)3}3(THF)2] (1-M; M = La, Ce, Pr, Nd, U); 1-M were also characterized by single crystal and powder X-ray diffraction, EPR, ATR-IR, and UV-vis-NIR spectroscopies, SQUID magnetometry, and elemental analysis. Only one SiMe3 signal was observed in the 29Si ssNMR spectra of 1-M, while two SiMe3 signals were seen in solution 29Si NMR spectra of 1-La and 1-Ce. This is attributed to dynamic averaging of the SiMe3 groups in 1-M in the solid state due to free rotation of the M-Si bonds and dissociation of THF from 1-M in solution to give the locally C 3v -symmetric complexes [M{Si(SiMe3)3}3(THF) n ] (n = 0 or 1), which show restricted rotation of M-Si bonds on the NMR time scale. Density functional theory and complete active space self-consistent field spin-orbit calculations were performed on 1-M and desolvated solution species to model paramagnetic NMR shifts. We find excellent agreement of experimental 29Si NMR data for diamagnetic 1-La, suggesting n = 1 in solution and reasonable agreement of calculated paramagnetic shifts of SiMe3 groups for 1-M (M = Pr and Nd); the NMR shifts for metal-bound 29Si nuclei could only be reproduced for diamagnetic 1-La, showing the current limitations of pNMR calculations for larger nuclei.
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Affiliation(s)
- Benjamin
L. L. Réant
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Fraser J. Mackintosh
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Gemma K. Gransbury
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Carlo Andrea Mattei
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Barak Alnami
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Benjamin E. Atkinson
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Katherine L. Bonham
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, U.K.
| | - Jack Baldwin
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Ashley J. Wooles
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | | | - Daniel Lee
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, U.K.
| | - Nicholas F. Chilton
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
- Research
School of Chemistry, The Australian National
University, Sullivans
Creek Road, Canberra 2601, Australian Capital Territory, Australia
| | - Stephen T. Liddle
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - David P. Mills
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
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Xiong F, Wang S, Kang C, Wang Y, Bai R, Li H, Yang J, Guo L. Geographical verification of Pleuropterus multiflorus thunb. by functional compounds, stable isotope ratios, and multielement combined with machine learning methods. Food Chem 2024; 440:138209. [PMID: 38104449 DOI: 10.1016/j.foodchem.2023.138209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/24/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
The dry roots of Pleuropterus multiflorus Thunb. (PM) have been traditionally utilized as functional foods and medicines China and various Asian countries. They are extensively cultivated in multiple provinces in China, with variations in prices and qualities. This study aims to investigate the regional characteristics of PM by 4 stable isotope ratios, 40 multielement and 16 functional compounds contents, using a total of 357 samples from 8 different geographical origins. Machine learning methods were developed to authenticating the geographical origins of PM, yielding the accuracy range from 94.44 % to 100 % in the test set. Notably, the protected designation of origin, Deqing PM, exhibited a high accuracy of 100 % in most models, A total of 30 significant prediction variables, encompassing 16 functional compounds, δ2H, 12 rare earth elements, and Cu, were identified. Additionally, the study identified altitude, high temperature, and dry or moisture index as the primary influenced environmental factors.
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Affiliation(s)
- Feng Xiong
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; Key Laboratory of Biology and Cultivation of Herb Medicine, Ministry of Agriculture and Rural Affairs, Beijing 100700, PR China
| | - Siman Wang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; Key Laboratory of Biology and Cultivation of Herb Medicine, Ministry of Agriculture and Rural Affairs, Beijing 100700, PR China
| | - Chuanzhi Kang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; Key Laboratory of Biology and Cultivation of Herb Medicine, Ministry of Agriculture and Rural Affairs, Beijing 100700, PR China
| | - Youyou Wang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; Key Laboratory of Biology and Cultivation of Herb Medicine, Ministry of Agriculture and Rural Affairs, Beijing 100700, PR China
| | - Ruibin Bai
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; Key Laboratory of Biology and Cultivation of Herb Medicine, Ministry of Agriculture and Rural Affairs, Beijing 100700, PR China
| | - Haiyan Li
- Institute of Information on Traditional Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing 100700, PR China
| | - Jian Yang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; Key Laboratory of Biology and Cultivation of Herb Medicine, Ministry of Agriculture and Rural Affairs, Beijing 100700, PR China.
| | - Lanping Guo
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China; Key Laboratory of Biology and Cultivation of Herb Medicine, Ministry of Agriculture and Rural Affairs, Beijing 100700, PR China
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Liu Z, Wang Y, Yuan Y, Luo F, Wang T, Han W, Tan L. Effect of Boron Additions on the Microstructural Evolution and Properties of Fe-Mo-Cu-Ni-C Sintered Steel. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6953. [PMID: 37959550 PMCID: PMC10648901 DOI: 10.3390/ma16216953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/04/2023] [Accepted: 10/18/2023] [Indexed: 11/15/2023]
Abstract
The effects of different boron (B) additions from 0 to 0.5 wt.% on the microstructure and properties of Fe-Mo-Cu-Ni-xB-C powder metallurgy (PM) steels were investigated in this work. The results indicated that the ferrite phase quantity decreased and disappeared, Ni/Cu became more homogeneous, and M2B phase formed, with the addition of B. The density and hardness of the sintered steels monotonously increased with increasing B content, whereas the tensile strength and impact toughness first increased and then decreased. The tensile strength of the steels reached a maximum value of 1097 MPa at a 0.2% B content, whereas the impact toughness reached a maximum value of 25.7 J/cm2 at a 0.1% B content and then sharply decreased when the B content exceeded 0.2%. Frictional wear experiments showed that the weight loss of the steels decreased with an increasing B content under low load conditions (100 N), and the lowest weight loss of 0.043 g occurred at a 0.2% B content. Under high load conditions (200 N), the 0.1% B content steel saw the lowest weight loss 0.075 g, exhibiting excellent wear resistance, but the abrasive resistance of the steels decreased with a further increase in the B content due to the germination of microcracks and large spalling caused by the high hardness and brittleness.
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Affiliation(s)
- Zenglin Liu
- China Iron and Steel Research Institute Group, Beijing 100081, China;
| | - Yankang Wang
- Shandong Luyin New Material Technology Co., Ltd., Jinan 271104, China; (Y.W.); (Y.Y.); (T.W.)
| | - Yong Yuan
- Shandong Luyin New Material Technology Co., Ltd., Jinan 271104, China; (Y.W.); (Y.Y.); (T.W.)
| | - Fenghua Luo
- State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
| | - Tao Wang
- Shandong Luyin New Material Technology Co., Ltd., Jinan 271104, China; (Y.W.); (Y.Y.); (T.W.)
| | - Wei Han
- China Iron and Steel Research Institute Group, Beijing 100081, China;
| | - Liming Tan
- State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
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Gransbury GK, Réant BLL, Wooles AJ, Emerson-King J, Chilton NF, Liddle ST, Mills DP. Electronic structure comparisons of isostructural early d- and f-block metal(iii) bis(cyclopentadienyl) silanide complexes. Chem Sci 2023; 14:621-634. [PMID: 36741509 PMCID: PMC9847655 DOI: 10.1039/d2sc04526e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
We report the synthesis of the U(iii) bis(cyclopentadienyl) hypersilanide complex [U(Cp'')2{Si(SiMe3)3}] (Cp'' = {C5H3(SiMe3)2-1,3}), together with isostructural lanthanide and group 4 M(iii) homologues, in order to meaningfully compare metal-silicon bonding between early d- and f-block metals. All complexes were characterised by a combination of NMR, EPR, UV-vis-NIR and ATR-IR spectroscopies, single crystal X-ray diffraction, SQUID magnetometry, elemental analysis and ab initio calculations. We find that for the [M(Cp'')2{Si(SiMe3)3}] (M = Ti, Zr, La, Ce, Nd, U) series the unique anisotropy axis is conserved tangential to ; this is governed by the hypersilanide ligand for the d-block complexes to give easy plane anisotropy, whereas the easy axis is fixed by the two Cp'' ligands in f-block congeners. This divergence is attributed to hypersilanide acting as a strong σ-donor and weak π-acceptor with the d-block metals, whilst f-block metals show predominantly electrostatic bonding with weaker π-components. We make qualitative comparisons on the strength of covalency to derive the ordering Zr > Ti ≫ U > Nd ≈ Ce ≈ La in these complexes, using a combination of analytical techniques. The greater covalency of 5f3 U(iii) vs. 4f3 Nd(iii) is found by comparison of their EPR and electronic absorption spectra and magnetic measurements, with calculations indicating that uranium 5f orbitals have weak π-bonding interactions with both the silanide and Cp'' ligands, in addition to weak δ-antibonding with Cp''.
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Affiliation(s)
- Gemma K Gransbury
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Benjamin L L Réant
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Ashley J Wooles
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Jack Emerson-King
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Nicholas F Chilton
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Stephen T Liddle
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - David P Mills
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
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5
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Réant BL, Wooles AJ, Liddle ST, Mills DP. Synthesis and Characterization of Yttrium Methanediide Silanide Complexes. Inorg Chem 2023; 62:137-146. [PMID: 36537859 PMCID: PMC9832533 DOI: 10.1021/acs.inorgchem.2c03053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The salt metathesis reactions of the yttrium methanediide iodide complex [Y(BIPM)(I)(THF)2] (BIPM = {C(PPh2NSiMe3)2}) with the group 1 silanide ligand-transfer reagents MSiR3 (M = Na, R3 = tBu2Me or tBu3; M = K, R3 = (SiMe3)3) gave the yttrium methanediide silanide complexes [Y(BIPM)(SitBu2Me)(THF)] (1), [Y(BIPM)(SitBu3)(THF)] (2), and [Y(BIPM){Si(SiMe3)3}(THF)] (3). Complexes 1-3 provide rare examples of structurally authenticated rare earth metal-silicon bonds and were characterized by single-crystal X-ray diffraction, multinuclear NMR and ATR-IR spectroscopies, and elemental analysis. Density functional theory calculations were performed on 1-3 to probe their electronic structures further, revealing predominantly ionic Y-Si bonding. The computed Y-Si bonds show lower covalency than Y═C bonds, which are in turn best represented by Y+-C- dipolar forms due to the strong σ-donor properties of the silanide ligands investigated; these observations are in accord with experimentally obtained 13C{1H} and 29Si{1H} NMR data for 1-3 and related Y(III) BIPM alkyl complexes in the literature. Preliminary reactivity studies were performed, with complex 1 treated separately with benzophenone, azobenzene, and N,N'-dicyclohexyl-carbodiimide. 29Si{1H} and 31P{1H} NMR spectra of these reaction mixtures indicated that 1,2-migratory insertion of the unsaturated substrate into the Y-Si bond is favored, while for the latter substrate, a [2 + 2]-cycloaddition reaction also occurs at the Y═C bond to afford [Y{C(PPh2NSiMe3)2[C(NCy)2]-κ4C,N,N',N'}{C(NCy)2(SitBu2Me)-κ2N,N'}] (4); these reactivity profiles complement and contrast with those of Y(III) BIPM alkyl complexes.
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Wang CJ, Liu C, Zhang MX, Jiang L, Liu Y, Liu ZB, Liang JX. Effect of Yttrium on the Microstructure and Mechanical Properties of PH13-8Mo Stainless Steels Produced by Selective Laser Melting. MATERIALS (BASEL, SWITZERLAND) 2022; 15:5441. [PMID: 35955376 PMCID: PMC9369835 DOI: 10.3390/ma15155441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/20/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
In the present work, PH13-8Mo stainless steel parts without yttrium and with yttrium (Y) were manufactured by selective laser melting (SLM). The microstructure, phase composition and grain orientation of the stainless steels parts with Y and without Y were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), electron-backscatter diffraction (EBSD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The characterization results revealed that the addition of Y clearly refined the grain size of the PH13-8Mo steel formed part, resulting in more equiaxed massive grains and in a less anisotropic microstructure. PH13-8Mo stainless steel formed parts were mainly composed of martensite and retained austenite. The addition of Y could significantly increase the content of retained austenite and also generate nano-sized precipitates containing Y. The mechanical test results showed that both strength and toughness of the shaped parts containing Y were improved synergistically. The yield strength reached 1443 MPa, the elongation was 12.2%, and the room temperature impact energy reached 124.25 J/cm2. The strengthening and toughening by Y of the formed parts were mainly attributed to grain refinement, higher volume fraction of the retained austenite and the formation of nano-sized precipitates containing Y.
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Affiliation(s)
- Chang-Jun Wang
- Central Iron & Steel Research Institute Company Limited, Beijing 100081, China
| | - Chang Liu
- Central Iron & Steel Research Institute Company Limited, Beijing 100081, China
| | - Meng-Xing Zhang
- Central Iron & Steel Research Institute Company Limited, Beijing 100081, China
| | - Lu Jiang
- Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia
| | - Yu Liu
- Central Iron & Steel Research Institute Company Limited, Beijing 100081, China
| | - Zhen-Bao Liu
- Central Iron & Steel Research Institute Company Limited, Beijing 100081, China
| | - Jian-Xiong Liang
- Central Iron & Steel Research Institute Company Limited, Beijing 100081, China
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Zhang S, Li Y, Wang P, Zhu F, Yang Y, Xiao B. Effect of Oxide Metallurgy on Inclusions in 125 ksi Grade OCTG Steel with Sulfide Stress Corrosion Resistance. MATERIALS 2022; 15:ma15134544. [PMID: 35806666 PMCID: PMC9267455 DOI: 10.3390/ma15134544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/09/2022] [Accepted: 06/24/2022] [Indexed: 11/16/2022]
Abstract
The effects of Al deoxidation and Zr deoxidation on the microstructure and properties of sulfide stress corrosion resistant high-strength steel have been investigated. The feasibility of the Zr deoxidation instead of Al deoxidation was confirmed by the thermodynamic analysis of the deoxidation of various elements. The experimental results indicate that the average diameters of the inclusions in Al-Steel and Zr-Steel were 2.45 μm and 1.65 μm, respectively. The Al-Steel and Zr-Steel contained 22.38% and 68.77% inclusions per unit area, respectively, and the fraction of inclusions in the Al-Steel and Zr-Steel with diameters less than 2 μm was about 73.46% and 89.63%, respectively, indicating that the Zr deoxidation process could effectively refine inclusions and promote dispersion. The average diameters of austenite grain for the Al-Steel and Zr-Steel were about 9.1 μm and 8 μm, respectively. The fine particles in Zr-Steel could pin the austenite grain boundaries and clearly refine the grains. The average grain size of tempered martensite was 8.2 μm and 3.8 μm, respectively. The yield strength of the Al-Steel and Zr-Steel was 922 MPa and 939 MPa, respectively; the impact energy was 60 ± 6 J and 132 ± 6 J, respectively. Moreover, the fracture time of the NACE-A was from 28 h (Al-Steel) to 720 h (Zr-Steel) without fracture. The experimental steel deoxidized by Zr achieved a simultaneous improvement in strength, toughness and sulfide stress corrosion resistance, and the effect of inclusions on the fracture of the sulfide stress corrosion resistant high-strength steel can be explained by the Griffith theory.
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Affiliation(s)
- Si Zhang
- Key Laboratory of Electromagnetic Processing of Materials, Northeastern University, Shenyang 110819, China; (S.Z.); (Y.Y.); (B.X.)
| | - Yanmei Li
- State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China;
- Correspondence: (Y.L.); (P.W.)
| | - Ping Wang
- Key Laboratory of Electromagnetic Processing of Materials, Northeastern University, Shenyang 110819, China; (S.Z.); (Y.Y.); (B.X.)
- Correspondence: (Y.L.); (P.W.)
| | - Fuxian Zhu
- State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China;
| | - Yulong Yang
- Key Laboratory of Electromagnetic Processing of Materials, Northeastern University, Shenyang 110819, China; (S.Z.); (Y.Y.); (B.X.)
| | - Bang Xiao
- Key Laboratory of Electromagnetic Processing of Materials, Northeastern University, Shenyang 110819, China; (S.Z.); (Y.Y.); (B.X.)
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Effect of Yttrium-Based Rare Earth on Inclusions and Cryogenic Temperature Impact Properties of Offshore Engineering Steel. CRYSTALS 2022. [DOI: 10.3390/cryst12030305] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
EH36 offshore engineering steels with varied yttrium-based rare earth content were prepared by trials in industrial production. The effects of yttrium-based rare earth on the inclusions and cryogenic temperature impact properties of EH36 offshore engineering steel were investigated by scanning electron microscopy, automatic statistics of inclusions, thermodynamic analysis and fracture morphology analysis. Yttrium-based rare earth could refine the inclusions and modify irregular Al2O3 and MnS inclusions into small, spherical, regular rare earth inclusions. The optimal impact properties were found in EH36 steel with 0.020 wt.% yttrium-based rare earth. Compared with 0RE steel, the RE-inclusions were within 3 μm (91.95% of total inclusions) in diameter and were spherical or quasi-spherical when dispersed in 200RE steel. Meanwhile, the cryogenic temperature impact properties significantly increased: 200RE steel impact properties were increased by 245.1% at −80 °C.
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Wang H, Gao X, Xing L, Zhai T, Lv M, Ren H, Wei H, Zhi J. Effects of RE (La, Ce) on fcc-bcc martensitic transformation of iron via Bain transformation path. J RARE EARTH 2021. [DOI: 10.1016/j.jre.2021.09.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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10
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Effect of Cerium on the Microstructure and Inclusion Evolution of C-Mn Cryogenic Vessel Steels. MATERIALS 2021; 14:ma14185262. [PMID: 34576484 PMCID: PMC8471360 DOI: 10.3390/ma14185262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 12/03/2022]
Abstract
The effects of Cerium (Ce) were studied on the casting slab quality, microstructure, and inclusion evolution of cryogenic vessel steel. An optical metallographic microscope, scanning electron microscope, energy dispersive spectrometer, and Thermo-calc thermodynamic software were used for characterization and analysis. The results indicated that the central segregation was significantly improved after adding Ce and reached the lowest level when the content of Ce was 0.0009 wt.%. Meanwhile, the presence of Ce reduces the size of ferrite and improves pearlite morphology. Ce also enables the modification of Al2O3 and MnS + Ti4C2S2 inclusions into ellipsoid CeAlO3 and spherical Ce2O2S + Ti4C2S2 composite inclusions, respectively, which are easier to remove. The formed Ce2O2S inclusions are fine and can work as heterogeneous nucleation points to refine the microstructure of steel.
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The Effect of Rare Earth Metals Alloying on the Internal Quality of Industrially Produced Heavy Steel Forgings. MATERIALS 2021; 14:ma14185160. [PMID: 34576384 PMCID: PMC8472719 DOI: 10.3390/ma14185160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 11/18/2022]
Abstract
The paper presented the findings obtained by industrial research and experimental development on the use of rare earth metals (REMs) in the production of heavy steel ingots and their impact on the internal quality of the 42CrMo4 grade steel forging. REMs alloying was carried out after vacuuming the steel. A relatively large melting loss of cerium (about 50%) and its further decrease in casting due to reoxidation were observed. Refinement of structure and better mechanical properties of forged bar containing about 0.02 wt.% of Ce compared to that of the standard production were not achieved. The wind power shaft with content of about 0.06 wt.% of Ce showed high amount of REM inclusions, which were locally chained, and in some cases, initiated cracks. Four stoichiometrically different types of REM inclusions were detected in forgings, namely (La-Ce)2O2S + (La-Ce)O2 + SiO2 (minority); oxygen, phosphorus, arsenic, and antimony bound to lanthanum and cerium probably bonded with iron oxides La + Ce, MgO, Al2O3 a SiO2; (La-Ce)2O2S, FeO, SiO2, and CaO or CaS.
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Gong J, Wang X, Liao H, Zhang K. Microstructure and mechanical properties of laser beam welded joints of China low-activation ferritic/martensitic steel with cerium addition. FUSION ENGINEERING AND DESIGN 2021. [DOI: 10.1016/j.fusengdes.2021.112494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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The Effect of Electrochemical Composite Coatings with LaF 3-LaB 6 Particles in Nickel-Copper Matrix on the Metallurgical Processes in Arc Welding of Low Alloy Ferrite-Pearlite Steels. MATERIALS 2021; 14:ma14061509. [PMID: 33808803 PMCID: PMC8003712 DOI: 10.3390/ma14061509] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 11/16/2022]
Abstract
Development of welding consumables with fluorides and borides of rare earth metals is a promising area for improving the weldability of low alloy steels. As lanthanum fluoride and boride dissociate, lanthanum and boron dissolve in the weld pool and the welding arc plasma is saturated with fluorine. As a result of FeO, MnO, SiO2 deoxidation and FeS, MnS desulfurization, refractory lanthanum sulfides and oxides La2O3, La2S3 are formed in the weld pool, which can be the crystallization nuclei in the weld pool and the origin of acicular ferrite nucleation. The paper proposes a model of metallurgical processes in the arc and weld pool, as well as a model of electrochemical adsorption of Ni2+ cations in colloidal electrolytes during electrostatic deposition of nano-dispersed insoluble particles of LaF3 or LaB6 on the surface of wire. The paper discusses the constructional design of the welding wire and the technology for forming electrochemical composite coatings with copper and nickel matrix. The composite wires applied in the welding of low alloy steels make it possible to refine the microstructure, increase the tensile strength by 4% and the impact toughness of welds by 20%.
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Gong J, Liao H, Zhang K, Wang X. Heat treatment optimization of China low-activation ferritic/martensitic steel with cerium addition. FUSION ENGINEERING AND DESIGN 2020. [DOI: 10.1016/j.fusengdes.2020.111696] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Effects of Rare Earth Elements on Microstructure and Mechanical Properties of H13 Die Steel. METALS 2020. [DOI: 10.3390/met10070918] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effects of rare earth (RE) elements on the carbide distribution, transformation temperature, and mechanical properties of H13 die steels after annealing were systematically investigated by scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy. The results indicated that the addition of RE elements is helpful in increasing the fraction of the disrupted M23C6 carbide along the grain boundaries, hindering the migration of grain boundaries and improving the crack-formation and expansion resistance of the carbides in the tensile process. With the addition of RE, the Ac3 temperature increased by 11.4 °C and the diffusion of carbon atoms was pinned during the austenitizing process. Moreover, the carbides were modified by rare earth elements, and RE-inclusion promoted the transition of brittle-type failure to ductile-type failure. Therefore, the impact energy, hardness, and ultimate tensile strength improved significantly in the RE-modified H13 die steels.
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16
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Effects of Yttrium on Microstructure Stability and Tensile Properties of China Low Activation Martensitic Steel. METALS 2019. [DOI: 10.3390/met9040446] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study investigated the microstructural stability and mechanical properties exhibited by China low activation martensitic (CLAM) steels with different yttrium (Y) contents over 3000 h of aging at 550 °C. Scanning electron microscopy, electron backscatter diffraction analysis, and transmission electron microscopy were employed to investigate the microstructural evolution of the steels. Results indicated that grain boundary migration was slow and the Laves phase precipitation was delayed in Y-containing steels. Grain boundaries at different angles in 0Y and 6Y CLAM steels were significantly affected, and those in 36Y and 71Y alloys exhibited negligible changes during the long-term thermal aging. Moreover, Y contents had appreciable effects on the strength and toughness of the aged steels. The stable microstructure of Y-containing CLAM alloys is responsible for improved strength and impact toughness during aging.
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17
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Roles of Lanthanum and Cerium in Grain Refinement of Steels during Solidification. METALS 2018. [DOI: 10.3390/met8110884] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Refinement of as-cast structures is one of the most effective approaches to improve mechanical properties, formability, and surface quality of steel castings and ingots. In the past few decades, addition of rare earths (REs), lanthanum and cerium in particular, has been considered as a practical and effective method to refine the as-cast steels. However, previous reports contained inconsistent, sometime even contradictory, results. This review summaries the major published results on investigation of the roles of lanthanum or/and cerium in various steels, provides reviews on the similarity and difference of previous studies, and clarifies the inconsistent results. The proposed mechanisms of grain refinement by the addition of lanthanum or/and cerium are also reviewed. It is concluded that the grain refinement of steels by RE additions is attributed to either heterogeneous nucleation on the in-situ formed RE inclusions, a solute effect, or the combined effect of both. The models/theories for evaluation of heterogeneous nucleation potency and for solute effect on grain refinement of cast metals are also briefly summarized.
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Kim DW, Sohn SS, Kim WK, Kim KS, Lee S. Study of Bauschinger effect of acicular ferrite and polygonal ferrite through ex-situ interrupted bending tests in API X80 linepipe steels. Sci Rep 2018; 8:15598. [PMID: 30348971 PMCID: PMC6197288 DOI: 10.1038/s41598-018-34046-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/09/2018] [Indexed: 11/19/2022] Open
Abstract
Linepipe steels complexly consisted of low-temperature transformation microstructures of bainitic ferrite, granular bainite, and acicular ferrite (AF) as well as polygonal ferrite (PF) which individually affect the Bauschinger effect occurring during the pipe-forming. In this study, microscopic analyses of electron back-scattered diffraction (EBSD) coupled with tension-compression and interrupted bending tests were performed for verification of the Bauschinger effect of AF and PF working as major microstructures in single-phase- and two-phase-rolled API X80 steels, respectively. With respect to microstructural effects on Bauschinger effect, the reduction in mobile dislocation density during the flattening was smaller in the AF than in the PF. However, the dislocation pile-up at low-angle substructures and high-angle grain boundaries was more frequently observed, thereby leading to the higher back stress and Bauschinger effect in the AF. Boundary kernel average misorientation (KAM) profile played a critical role in determining the Bauschinger effect because they were closely related with the back stress. Thus, the Bauschinger effect was higher in the single-phase-rolled steel than in the two-phase-rolled steel. The present ex-situ interrupted bending methods coupled with EBSD analyses are outstanding ones for the detailed explanation of Bauschinger effect and provide an important idea for the yield strength designs of linepipe steels.
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Affiliation(s)
- Dae Woong Kim
- Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Seok Su Sohn
- Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237, Düsseldorf, Germany.
| | - Wan-Keun Kim
- POSCO Computational Optimization of API steels Project Team, Technical Research Laboratories, POSCO, Kwangyang, 545-875, Korea
| | - Ki-Seok Kim
- Structural Research Group, Steel Solution Marketing Department, POSCO, Incheon, 406-840, Korea
| | - Sunghak Lee
- Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784, Korea
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19
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Abstract
Ceria is the main component in glass polishing powders due to its special physico-chemical properties. Glass polishing powder loses its polishing ability gradually during usage due to the accumulation of other compounds on the polishing powder or due to changes in the particle size distribution. The recovery of cerium from the glass polishing waste results in the efficient utilization of natural resources. This paper reviews processes for the recovery of rare earths from polishing waste. Glass polishing powder waste can be reused via physical, physico-chemical or chemical processes by removing silica and/or alumina. The removal of silica and/or alumina only improves the life span up to some extent. Therefore, removal of other elements by chemical processes is required to recover a cerium or cerium-rich product. However, cerium leaching from the polishing waste is challenging due to the difficulties associated with the dissolution of ceria. Therefore, high acid concentrations, high temperatures or costly reducing agents are required for cerium dissolution. After leaching, cerium can be extracted from the leach solution by solvent extraction or selective precipitation. The product can be used either in glass polishing again or other high value added applications.
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20
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Electrical Conductivity and Optical Properties of Pulsed Laser Deposited LaNi₅ Nanoscale Films. MATERIALS 2018; 11:ma11081475. [PMID: 30126256 PMCID: PMC6120037 DOI: 10.3390/ma11081475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 02/07/2023]
Abstract
This work presents pulsed laser deposition as a method to obtain unoxidized LaNi₅ nanoscale films and describes their temperature and thickness dependent electrical conductivity and the spectral dispersions of some optical properties. AB₅-type rare earth element (REE)-nickel compounds are currently studied from both theoretical and practical points of view. Special challenges are posed during the preparation of these nanomaterials, which can be overcome using finely tuned parameters in a preparation process that always involves the use of high energies. Film deposition was made by laser-induced vaporization, with short and modulated impulses and electro⁻optical tuning of the quality factor, mainly on glass and one SiO₂ substrate. Deposition geometry dependent linear thickness increase, between 1.5⁻2.5 nm per laser burst, was achieved. Film structures and phase compositions were determined using XRD and discussed in comparison with films obtained by similar deposition procedures. Temperature and scale dependent properties were determined by studying electrical conductivity and optical properties. Electrical conductivity was measured using the four-probe method. The observed semiconductor-like conductivity for film thicknesses up to 110 nm can be explained by thermal activation of electrons followed by inter-insular hopping or quantum tunneling, which, on the other hand, modulates the material's native metallic conductance. Films with thicknesses above this value can be considered essentially metallic and bulk-like. The spectral behaviors of the refractive index and absorption coefficient were deduced from differential reflectance spectroscopy data acquired on a broad ultraviolet, visible, near- and mid-infrared (UV-VIS-NIR-MIR) domain, processed using the Kramers-Krönig formalism. Their study led to the identification of the allowed interband transitions. Electronic behavior in the energy bands near the Fermi level and in the surface and interface-states was described, discussing the differences between experimental data and the classical free-electron theoretical model applied for the bulk intermetallic alloy, in correlation with theoretical optical properties or experimental X-ray photoelectron spectroscopy (XPS) results from references. However, the dielectric-like shape of the reflectance of the thinnest film was in accordance with the Lorentz⁻Drude model.
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21
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The Effect of Gadolinium on the Microstructures and Charpy Impact Properties of Super Duplex Stainless Steels. METALS 2018. [DOI: 10.3390/met8070474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Study on the Control of Rare Earth Metals and Their Behaviors in the Industrial Practical Production of Q420q Structural Bridge Steel Plate. METALS 2018. [DOI: 10.3390/met8040240] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Additive Manufacturing of a 316L Steel Matrix Composite Reinforced with CeO2 Particles: Process Optimization by Adjusting the Laser Scanning Speed. TECHNOLOGIES 2018. [DOI: 10.3390/technologies6010025] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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24
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The Influence of La and Ce Addition on Inclusion Modification in Cast Niobium Microalloyed Steels. METALS 2017. [DOI: 10.3390/met7090377] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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25
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Inclusions properties at 1673 K and room temperature with Ce addition in SS400 steel. Sci Rep 2017; 7:2564. [PMID: 28566704 PMCID: PMC5451397 DOI: 10.1038/s41598-017-02478-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 04/13/2017] [Indexed: 11/24/2022] Open
Abstract
Inclusion species formed in SS400 steel with Ce-addition was predicted by thermodynamic calculation. The analysis of the inclusion morphology and size distribution was carried out by applying Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM). Nano-Fe3O4 particles were also found in cerium-deoxidized and -desulfurized steel and their shapes were nearly spherical. The complex Ce2O3 inclusions covering a layer of 218 nm composed by several MnS particles with similar diffraction pattern. Most importantly, the complex Ce2O3 characterized by using TEM diffraction is amorphous in the steel, indicating that Ce2O3 formed in the liquid iron and then MnS segregated cling to it.
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Thermodynamic Calculation among Cerium, Oxygen, and Sulfur in Liquid Iron. Sci Rep 2016; 6:35843. [PMID: 27767092 PMCID: PMC5073290 DOI: 10.1038/srep35843] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 10/06/2016] [Indexed: 11/08/2022] Open
Abstract
Thermodynamic calculation has been applied to predict the inclusion formation in molten SS400 steel. When the Cerium addition in liquid iron is 70 ppm and the initial Oxygen and Sulphur are both 110 ppm, the formation of oxides containing Cerium would experience the transformation from Ce2O3 to CeO2 and also the formation of sulfides containing Cerium would experience the transformation from CeS to Ce2S3 and then to Ce3S4. Below 2000 K the most thermodynamic stable matter is CeO2 and the less thermodynamic stable inclusion is CeS. Only when the amount of [O] is extremely low and the amount of [S] and [Ce] is relatively high, Ce2S3 has the possibility to form.
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