共查询到20条相似文献,搜索用时 15 毫秒
1.
Metallurgical and Materials Transactions A - The limits of occurrence and the morphology of martensite in Cu-Zn-Al alloys with 30 to 50 wt pct Zn and ≤ 1.5 wt pct Al... 相似文献
2.
Kohne Thomas Fahlkrans Johan Stormvinter Albin Maawad Emad Winkelmann Aimo Hedström Peter Borgenstam Annika 《Metallurgical and Materials Transactions A》2023,54(4):1083-1100
Metallurgical and Materials Transactions A - The martensitic transformation was studied by in situ and ex situ experiments in two high-carbon, 0.54 and 0.74 wt pct C, steels applying three... 相似文献
3.
Metallurgical and Materials Transactions B - The phase equilibria of the TiO2-CaO-SiO2-10 wt pct Al2O3-5 wt pct MgO system in the TiO2-rich part were... 相似文献
4.
Scrap-based electric arc furnace (EAF) steelmaking is limited by a surface cracking problem in the recycled steel products,
which is known as surface hot shortness. This problem originates from the excessive amount of copper (Cu) in the steel scrap, which enriches during the oxidation
of iron (Fe) and consequently melts and penetrates into the austenite grain boundaries. In this article, the effects of arsenic
(As), antimony (Sb), and tin (Sn) on surface hot shortness were investigated. A series of Fe-0.3 wt pct Cu-x wt pct (As, Sb, or Sn) alloys with x content ranging from 0.06 to 0.10 wt pct was oxidized in air at 1423 K (1150 °C) for 60, 300, and 600 seconds inside the
chamber of a thermogravimety analyzer (TGA) where heat is supplied through infrared radiation. Scanning electron microscopy
(SEM) investigations show that (1) the presence of Sb and Sn results in severe grain boundary cracking, whereas the presence
of As does not, (2) open cracks with Fe oxides were found beneath the oxide/metal interface in the Sb and Sn alloys, and (3)
the oxide/metal interfaces for all As, Sb, and Sn alloys are planar. Penetration experiments of pure Cu and Cu-30 wt pct Sn
liquid were also conducted in the chamber of a hot-stage confocal laser scanning microscopy (CLSM) in nonoxidizing atmosphere:
(1) on the Fe-35 wt pct manganese (Mn) alloys to study the correlation between cracking and grain boundary characters, and
(2) on the pure Fe substrates to exclude the bulk segregation effects of Sn on grain boundary cracking. It was found that
grain boundary cracking rarely took place on low-energy grain boundaries. The results also suggest that the bulk segregation
of Sn in the substrate is not necessary to promote significant grain boundary cracking, and as long as the liquid phase contains
Sn, it will be highly embrittling. 相似文献
5.
Metallurgical and Materials Transactions B - The activities of MnO in the MnO-CaO-SiO2-Al2O3 (10, 20, and 30 mass pct)-MgO (5 mass pct) melts at 1873 K... 相似文献
6.
Metallurgical and Materials Transactions A - This paper concerns the β-phase depletion kinetics of a thermally sprayed free-standing CoNiCrAlY (Co-31.7 pct Ni-20.8 pct... 相似文献
7.
K. R. Ravi S. Manivannan G. Phanikumar B. S. Murty Suresh Sundarraj 《Metallurgical and Materials Transactions A》2011,42(7):2028-2039
Although the grain-refinement practice is well established for wrought Al alloys, in the case of foundry alloys such as near
eutectic Al-Si alloys, the underlying mechanisms and the use of grain refiners need better understanding. Conventional grain
refiners such as Al-5Ti-1B are not effective in grain refining the Al-Si alloys due to the poisoning effect of Si. In this
work, we report the results of a newly developed grain refiner, which can effectively grain refine as well as modify eutectic
and primary Si in near eutectic Al-Si alloys. Among the material choices, the grain refining response with Al-1Ti-3B master
alloy is found to be superior compared to the conventional Al-5Ti-1B master alloy. It was also found that magnesium additions
of 0.2 wt pct along with the Al-1Ti-3B master alloy further enhance the near eutectic Al-Si alloy’s grain refining efficiency,
thus leading to improved bulk mechanical properties. We have found that magnesium essentially scavenges the oxygen present
on the surface of nucleant particles, improves wettability, and reduces the agglomeration tendency of boride particles, thereby
enhancing grain refining efficiency. It allows the nucleant particles to act as potent and active nucleation sites even at
levels as low as 0.2 pct in the Al-1Ti-3B master alloy. 相似文献
8.
Meka S. R. Schubert A. Bischoff E. Mittemeijer E. J. 《Metallurgical and Materials Transactions A》2020,51(6):3154-3166
Metallurgical and Materials Transactions A - The influence of Si, substitutionally dissolved in ferritic Fe-2 at. pct Si and Fe-4.5 at. pct Si alloys, on the nucleation and growth... 相似文献
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10.
Zarif Muhammad Mckay Brian Schumacher Peter 《Metallurgical and Materials Transactions A》2011,42(6):1684-1691
Al-5 wt pct Si master-alloys with controlled Sr and/or P addition/s were produced using super purity Al 99.99 wt pct and Si
99.999 wt pct materials in an arc melter. The master-alloy was melt-spun resulting in the production of thin ribbons. The
Al matrix of the ribbons contained entrained Al-Si eutectic droplets that were subsequently investigated. Differential scanning
calorimetry, thermodynamic calculations, and transmission electron microscopy techniques were employed to examine the effect
of the Sr and P additions on eutectic undercoolings and nucleation phenomenon. Results indicate that, unlike P, Sr does not
promote nucleation. Increasing Sr additions depressed the eutectic nucleation temperature. This may be a result of the formation
of a Sr phase that could consume or detrimentally affect potent AlP nucleation sites. 相似文献
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The Effect of Nb Addition on the Microstructure and the High-Temperature Strength of Fe3Al Aluminide
Kratochvíl Petr Švec Martin Král Robert Veselý Jozef Lukáč Pavel Vlasák Tomáš 《Metallurgical and Materials Transactions A》2018,49(5):1598-1603
Metallurgical and Materials Transactions A - The microstructural and high-temperature mechanical properties of Fe–26Al–xNb (x = 3 and 5 at. pct) are... 相似文献
15.
M. Ahmed K. Hasnain I. Nasim H. Ayub 《Metallurgical and Materials Transactions A》1995,26(7):1869-1876
Magnetic properties of maraging steels have been investigated as a function of nickel concentration. The alloys nickel content
varied from 12 to 24 wt pct, while other alloying constituents were kept at a level maintained in the 18Ni-2400 MPA-grade
maraging steel. The magnetic properties were determined following aging for 1 hour in the temperature range of 450 °C to 750
°C. In every alloy investigated, the coercive field increased with aging temper-ature, reaching a maximum around 670 °C ±
30 °C. The saturation magnetization values were lowest around temperatures where maximum coercive field was observed. The
coercive field increased from ∼55 to ∼ 175 Oe (∼4380 to ∼ 13,900 amp/meter) and the corresponding sat-uration magnetization
decreased from ∼18,500 to ∼ 4000 G (∼1.85 to ∼0.4 T) in the alloys containing 12 and 24 wt pct Ni, respectively. The reverted
austenite increased from 25 vol pct at 12 wt pct Ni to 100 vol pct at 24 wt pct Ni. The hardness and Charpy impact strength
of the alloys have also been determined. An attempt has been made to correlate magnetic properties with different phase transformations
occurring in maraging steels. 相似文献
16.
Meshram Atul P. Gupta Abhay Srivastava Chandan 《Metallurgical and Materials Transactions A》2022,53(4):1430-1439
Metallurgical and Materials Transactions A - Ni–P coatings with low P content (P wt pct < 1.0) were fabricated at different applied current densities of electrodeposition... 相似文献
17.
Zapico-Álvarez David Barges Patrick Musik Céline Bertrand Florence Mataigne Jean-Michel Descoins Marion Mangelinck Dominique Giorgi Marie-Laurence 《Metallurgical and Materials Transactions A》2020,51(5):2391-2403
Metallurgical and Materials Transactions A - In the galvannealing process, steel strips are immersed in molten zinc containing 0.100 to 0.135 wt pct Al at 450 °C.... 相似文献
18.
Development of New High-Strength Carbide-Free Bainitic Steels 总被引:1,自引:0,他引:1
An attempt was made to optimize the mechanical properties by tailoring the process parameters for two newly developed high-strength
carbide-free bainitic steels with the nominal compositions of 0.47 pct C, 1.22 pct Si, 1.07 pct Mn, 0.7 pct Cr (S1), and 0.30 pct
C, 1.76 pct Si, 1.57 pct Mn, and 0.144 pct Cr (S2) (wt pct), respectively. Heat treatment was carried out via two different routes: (1) isothermal transformation and (2) quenching followed by isothermal tempering. The results for the
two different processes were compared. The bainitic steels developed by isothermal heat treatment were found to show better
mechanical properties than those of the quenched and subsequently tempered ones. The effect of the fraction of the phases,
influence of the transformation temperatures, the holding time, and the stability of retained austenite on the mechanical
properties of these two steels was critically analyzed with the help of X-ray diffraction, optical metallography, scanning
electron microscopy, and atomic force microscopy. Finally, a remarkable combination of yield strength of the level of 1557 MPa
with a total elongation of 15.5 pct was obtained. 相似文献
19.
Sitdikov O. Avtokratova E. Markushev M. Sakai T. 《Metallurgical and Materials Transactions A》2023,54(2):505-525
Metallurgical and Materials Transactions A - Microstructure evolution in Al-3 wt pct Cu alloy during equal-channel angular pressing (ECAP) at 423 K (150 °C)... 相似文献
20.
H. Guo G. R. Purdy M. Enomoto H. I. Aaronson 《Metallurgical and Materials Transactions A》2006,37(6):1721-1729
A low-carbon balloy steel with relatively high Mn and Si concentrations (0.04 wt pct C-3 wt pct Mn-1.9 wt pct Si) has been
used to explore the effects of alloy chemistry and austenite grain size on ferrite growth. Even at high levels of supersaturation,
the volume fraction of ferrite is found to increase slowly relative to the relaxation time for carbon diffusion. A series
of scanning transmission electron microscopy (STEM) analyses for Mn indicates that initial unpartitioned ferrite growth is
replaced by partitioned growth, accompanied by a dramatic drop in growth rate, and a persistent level of residual supersaturation
in the remaining austenite. The results are interpreted in terms of a transition from an initial paraequilibrium interfacial
condition to partitioned ferrite growth.
This article is based on a presentation made in the “Hillert Symposium on Thermodynamics & Kinetics of Migrating Interfaces
in Steels and Other Complex Alloys,” December 2–3, 2004, organized by The Royal Institute of Technology in Stockholm, Sweden. 相似文献