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1.
A. Inoue Y. Kojima T. Minemura T. Masumoto 《Metallurgical and Materials Transactions A》1981,12(7):1245-1253
By the rapid quenching technique, nonequilibrium Ni3Al-type compounds with high strength and hardness as well as large elongation have been found in Fe-Ni-Al-C and Fe-Mn-Al-C
systems. This formation region is limited to about 7 to 55 wt pct Ni, 3 to 9 wt pct Al and 0.8 to 2.4 wt pct C for Fe-Ni-Al-C
and to about 7 to 65 wt pct Mn, 3 to 9 wt pct Al and 0.8 to 2.4 wt pct C for Fe-Mn-Al-C. The Ni3Al-type compound has fine grains of about 1 to 10 μm in diam. Their Vickers hardness and yield strength increase with increase
in the amounts of carbon, aluminum or nickel and the highest values attain about 665 DPN and 1690 MPa for Fe-Ni-Al-C and 600
DPN and 1740 MPa for Fe-Mn-Al-C. Elongation increases with decrease in carbon or aluminum and attains about 11 pct for Fe-20
wt pct Ni-6 wt pct Al-1.2 wt pct C and 28 pct for Fe-20 wt pct Mn-8 wt pct Al-1.6 wt pct C. The good strength and ductility
of the Ni3Al-type compounds remain unchanged on tempering for 1 h until heated to about 750 K. Further, it has been found that the addition
of chromium, molybdenum or cobalt is effective for the improvement of mechanical properties and thermal stability of the compounds.
Thus, the use of materials containing Ni3Al-type compounds may be attractive for fine gage high-strength wire or plate applications.
Formerly Graduate Student of Tohoku University. 相似文献
2.
Effect of processing and heat treatment on behavior of Cu-Cr-Zr alloys to railway contact wire 总被引:3,自引:0,他引:3
Qiang Liu Xiang Zhang Yan Ge Jing Wang Jian-Zhong Cui 《Metallurgical and Materials Transactions A》2006,37(11):3233-3238
A new series of Cu-Cr-Zr alloys to be used as railway contact wire, Cu-0.26 wt pct Cr-0.15 wt pct Zr, Cu-0.13 wt pct Cr-0.41
wt pct Zr, and Cu-0.34 wt pct Cr-0.41 wt pct Zr, were studied. The results indicated that processing and aging treatment had
an effect on the microstructure, tensile strength, and electrical conductivity behavior of the Cu-Cr-Zr alloys. Process I
(solution treatment + cold work + aging) was superior to process II (cold work + solution treatment + aging), because precipitation
can occur heterogeneously at the dislocations and subcells. An appropriate processing and aging treatment may improve the
properties of the alloys due to the formation of fine, dispersive, and coherent precipitates within the matrix. It is demonstrated
that the best combination of tensile strength and electrical conducitivity, on the order of 599 MPa and 82 pct IACS (International
Annealed Copper Standard), respectively, can be obtained in alloy Cu-0.34 wt pct Cr-0.41 wt pct Zr in the solution-heat-treated,
cold-worked, and aged condition. The mechanism of tensile and conductive properties of Cu-Cr-Zr alloy is also discussed. 相似文献
3.
M. Nageswararao C. J. McMahon H. Herman 《Metallurgical and Materials Transactions B》1974,5(5):1061-1068
The solid solubilities of Sn and Sb in α-Fe have been determined by means of lattice parameter measurements. The Sb solubility
ranges from a maximum of 11 wt pct (5.4 at. pct) at 1000°C down to 5.3 wt pct (2.5 at. pet) at 600°C; the Sn solubility ranges
from a maximum of 17.7 wt pct (9.2 at. pet) at 900°C to 6.5 wt pct (3.2 at. pet) at 600°C. These solubilities are remarkably
large in view of the large sizes of the Sb and Sn atoms in relation to the Fe atom. It was not possible to rationalize the
variation of the α-phase lattice parameter with Sb or Sn content from the point of view of atomic diameter or atomic volume.
The addition of 1 wt pct Ni lowers the Sb solubility at 600°C from 5.3 to 3.5 wt pct (2.5 to 1.6 at. pet); the effect of Cr
on the Sb solubility appears to be small. The addition of 1 wt pct Ni or 1 wt pct Cr lowers the Sn solubility from 6.5 to
5.2 wt pct (3.2 to 2.5 at. pet). It was found that a substantial amount of Ni substitutes for Fe in both the FeSb phase and
the Fe5Sn3 phase.
Formerly Research Fellow, Department of Metallurgy and Materials Science and LRSM, University of Pennsylvania 相似文献
4.
Seungmun Jung Yong Hee Jo Changwoo Jeon Won-Mi Choi Byeong-Joo Lee Yong-Jun Oh Gi-Yong Kim Seongsik Jang Sunghak Lee 《Metallurgical and Materials Transactions A》2017,48(2):568-574
High-temperature tensile properties of austenitic cast steels fabricated by replacing Ni by Mn in a 20 wt pct Ni-containing steel were investigated. In a steel where 8 wt pct Ni was replaced by 9.2 wt pct of Mn, 17.4 and 9.8 pct of ferrite existed in equilibrium phase diagrams and actual microstructures, respectively, because a role of Mn as an austenite stabilizer decreased, and led to deterioration of high-temperature properties. When 2 to 6 wt pct Ni was replaced by 2.3 to 6.9 wt pct Mn, high-temperature properties were comparable to those of the 20 wt pct Ni-containing steel because ferrites were absent, which indicated the successful replacement of 6 wt pct Ni by Mn, with cost reduction of 27 pct. 相似文献
5.
Metallurgical and Materials Transactions A - The solid solution and grain boundary hardening due to Mg in Al-1.5wt pct Mn-0.5wt pct Cu system with 0.1 to 2.1 wt pct Mg has been studied at... 相似文献
6.
The microstructure and properties of three different Al-Zn-Mg-Cu alloys with high Zn content (9 wt pct, 10 wt pct, and 11 wt pct, marked as 9Zn, 10Zn, and 11Zn, respectively) were investigated. The strength of alloys increases as the Zn content increases from 9 wt pct to 10 wt pct, while it does not increase any more as the Zn content increases continuously from 10 wt pct to 11 wt pct. The stress-corrosion cracking (SCC) resistance decreases as the Zn content increases from 9 wt pct to 10 wt pct, while it changes unobviously as the Zn content increases continuously from 10 wt pct to 11 wt pct. The elongation and fracture toughness of alloys decrease as the Zn content increases in these Al-Zn-Mg-Cu alloys. The Zn content has little effect on the precipitation reaction of Al-Zn-Mg-Cu alloys that contain the mixture of GP zones, and η′ are the main Matrix Precipitates (MPt) in the peak-aging state, and the mixture of η′ and η are the main MPt in the over-aging state. The amount of MPt and coarse T (AlZnMgCu) phases are shown to increase with the increasing Zn content in Al-Zn-Mg-Cu alloys. The coarse T phases hardly dissolve into the matrix and are the source for the crack initiation, which may be the responsibility for the negative effect on the properties of high Zn content Al-Zn-Mg-Cu alloys. 相似文献
7.
A combined 3.5 wt pct Mo + 1.2 wt pct Ti imparted dynamic recrystallization in a 35 wt pct Fe-45 wt pct Ni-20 wt pct Cr alloy
system during creep at 700 °C, whereas 3.5 wt pct Mo addition alone did not initiate recrystallization. Dynamic recrystallization
substantially increased the creep elongation and produced a high ductile fracture topography in the present alloy system.
A subgrain coalescence nucleation mechanism for dynamic recrystallization mechanism was operative during creep. The critical
initiation strain requirements are also discussed. 相似文献
8.
Several ingots (0.0254 m in diam × 0.10 m long) of nickel-30 wt pct copper, nickel-10 wt pct cobalt and iron-25 wt pct nickel
were solidified with various undercoolings up to about 200 K, prior to nucleation of the solid. The materials were mechanically
tested in the ascast condition. In nickel-30 wt pct copper and iron-25 wt pct nickel alloys the 0.2 pct offset yield strength,
ductility and fatigue strength increased with undercooling. A linear relationship was established between 0.2 pct offset yield
strength and the square root of secondary dendrite arm spacing in dendritic alloys (undercooled less than 170 K) or that of
grain diameter in nondendritic alloys (undercooled more than 170 K). In iron-25 wt pct nickel limited testing indicated improvements
in Charpy V-notch impact strength and in fracture toughness with undercooling. No improvement of tensile properties with undercooling
was observed in nickel-10 wt pct cobalt, an alloy which solidified normally with very low microsegregation. 相似文献
9.
Dr. Stefan Heino 《Metallurgical and Materials Transactions A》2000,31(8):1893-1905
This study concerns the crystallographic identification and compositions of precipitates formed in superaustenitic stainless
steel. Three experimental alloys, all containing 24 wt pct Cr, 22 wt pct Ni, and 0.5 wt pct N but with varying amounts of
Mo and W, were investigated after sensitization heat treatment (aging) at 900 °C. The contents of Mo and W in the three alloys
were 7 wt pct Mo, (6 wt pct Mo + 2 wt pct W) and (5 wt pct Mo + 5 wt pct W), respectively. While σ and x were the main secondary phases found in the W-free alloy, replacement of Mo by W was found to promote the formation of Laves-related
phases with high Mo + W content. The complex crystallographic nature of Laves-related precipitates was exemplified through
the formation of intergrowing C14 Laves, μ, and C phases, all with closely related crystal structures. There was no difference in chemical composition between the three
phases. Prolonged aging resulted in intragranular precipitation of different intermetallic phases, as well as formation of
nitrogen bearing phases, π and Cr2N, adjacent to previously formed intermetallic precipitates. The content of Mo + W was found to decrease with increasing aging
time for all secondary phases. 相似文献
10.
Anish Karmakar Pooja Sahu Suman Neogy Debalay Chakrabarti Rahul Mitra Subrata Mukherjee Saurabh Kundu 《Metallurgical and Materials Transactions A》2017,48(4):1581-1595
Samples from two V-microalloyed steels (0.05 wt pct V) having different C and N levels, namely high-C low-N steel, HCLN (0.22 wt pct C, 0.007 wt pct N) and low-C high-N steel, LCHN (0.06 wt pct C, 0.013 wt pct N) were naturally cooled from 1373 K (1100 °C) to room temperature over a range of cooling rates (0.07 to 3.33 K/s). Samples from a plain C-Mn steel (0.06 wt pct C, 0.007 wt pct N) were also subjected to the same heat treatment for comparison. The effect of cooling rate and steel composition on microstructures, precipitates, and tensile properties has been investigated. Due to the presence of large fraction of harder constituents, like pearlite and bainite, HCLN steel showed higher strength and lower ductility than LCHN steel. LCHN steel, on the other hand, showed good combination of strength and ductility due to its predominantly ferrite matrix with precipitation strengthening. The V-precipitate size was more refined and the precipitate density was higher in HCLN steel than that in LCHN steel. This observation confirms the importance of C content in V-microalloyed steel in terms of precipitation strengthening. An intermediate cooling rate (~1.4 K/s) has been found to be the optimum choice in order to maximize the precipitation strengthening in V-containing steels. 相似文献
11.
The rates of desulfurization of Fe-O-S melts by CaO crucibles and by CaO-saturated liquid iron oxide have been measured at
1600 ‡C. It was found that irons containing 1.62 wt pct and 0.64 wt pct sulfur and 0.070 wt pct oxygen are desulfurized by
a reaction with the containing CaO crucible which does not involve the formation of a CaS product layer. The rate of desulfurization
reaction is controlled by diffusion of sulfur in the iron melt, and a value of 6.7 ±1.7 × 10-5 cm2 per second was obtained for the diffusion coefficient of sulfur in liquid iron. Iron containing 0.088 wt pct sulfur and 0.070
wt pct oxygen is not desulfurized by solid CaO. The rate of desulfurization of liquid iron containing 0.088 wt pct sulfur
and 0.070 wt pct oxygen by CaO-saturated liquid iron oxide is significantly greater than that calculated on the assumption
of diffusion control in the metal phase, and evidence is presented in support of speculation that the reaction rate is enhanced
by Marangoni turbulence at the slag-metal interface. The addition of 4 wt pct CaF2 to the CaO-saturated liquid iron oxide has no influence on the rate of desulfurization of the melt.
A. Saelim formerly Lecturer, Faculty of Engineering, Prince of Songkla University, Thailand 相似文献
12.
M. J. Cieslak C. R. Hills P. F. Hlava S. A. David 《Metallurgical and Materials Transactions A》1990,21(9):2465-2475
Differential thermal analysis (DTA), high-temperature water-quench (WQ) experiments, and optical and electron microscopy were used to establish the near-solidus and solidification microstructures in PH 13-8 Mo. On heating at a rate of 0. 33 °C/s, this alloy begins to transform from austenite to δ-ferrite at ≈1350 °C. Transformation is complete by ≈1435 °C. The solidus is reached at ≈1447 °C, and the liquidus is ≈1493 °C. On cooling from the liquid state at a rate of 0. 33 °C/s, solidification is completed as δ-ferrite with subsequent transformation to austenite beginning in the solid state at ≈1364 °C. Insufficient time at temperature is available for complete transformation and the resulting room-temperature microstructure consists of matrix martensite (derived from the shear decomposition of the austenite) and residual δ-ferrite. The residual δ-ferrite in the DTA sample is enriched in Cr (≈16 wt pct), Mo (≈4 wt pct), and Al (≈1. 5 wt pct) and depleted in Ni (≈4 wt pct) relative to the martensite (≈12. 5 wt pct Cr, ≈2 wt pct Mo, ≈1 wt pct Al, ≈9 wt pct Ni). Solid-state transformation of δσ γ was found to be quench-rate sensitive with large grain, fully ferritic microstructures undergoing a massive transformation as a result of water quenching, while a diffusionally controlled Widmanstätten structure was produced in air-cooled samples. 相似文献
13.
Gerhard Leichtfried Joachim H. Schneibel Martin Heilmaier 《Metallurgical and Materials Transactions A》2006,37(10):2955-2961
Mo-Re alloys containing between 5 and 47.5 wt pct Re were fabricated from Mo and Mo-Re powders by sintering and hot radial
forging. The mechanical properties of as-forged, stress-relieved, and recrystallized specimens were examined. Up to a concentration
of 41 wt pct Re, the Charpy ductile-to-brittle transition temperature decreased monotonically with increasing rhenium concentration.
Consistent with this, bend angles for fracture at T=−100 °C increased monotonically with increasing rhenium concentration. Between 10 and 41 wt pct rhenium, the room-temperature
tensile ductility of recrystallized Mo-Re remained nearly constant with values on the order of 35 to 45 pct. This result differs
from the low ductility values observed previously by Lundberg (1997) for compositions on either side of Mo-13 wt pct Re. 相似文献
14.
D. G. Kolman J. F. Bingert R. D. Field 《Metallurgical and Materials Transactions A》2004,35(11):3445-3454
The mechanical and fracture properties of austenitic stainless steels (SSs) alloyed with gallium require assessment in order
to determine the likelihood of premature storage-container failure following Ga uptake. AISI 304 L SS was cast with 1, 3,
6, 9, and 12 wt pct Ga. Increased Ga concentration promoted duplex microstructure formation with the ferritic phase having
a nearly identical composition to the austenitic phase. Room-temperature tests indicated that small additions of Ga (less
than 3 wt pct) were beneficial to the mechanical behavior of 304 L SS but that 12 wt pct Ga resulted in a 95 pct loss in ductility.
Small additions of Ga are beneficial to the cracking resistance of stainless steel. Elastic-plastic fracture mechanics analysis
indicated that 3 wt pct Ga alloys showed the greatest resistance to crack initiation and propagation as measured by fatigue
crack growth rate, fracture toughness, and tearing modulus. The 12 wt pct Ga alloys were least resistant to crack initiation
and propagation and these alloys primarily failed by transgranular cleavage. It is hypothesized that Ga metal embrittlement
is partially responsible for increased embrittlement. 相似文献
15.
Martins Freitas Brenda Juliet Jorge Junior Alberto Moreira Zepon Guilherme Kiminami Claudio Shyinti Botta Walter José Bolfarini Claudemiro 《Metallurgical and Materials Transactions A》2020,51(6):2703-2710
Metallurgical and Materials Transactions A - Cast Al(5.5 to 6.3 wt pct)Si-(3.1 to 3.7 wt pct)Cu alloys containing 0.6 and 1.2 wt pct Fe were processed by spray forming, rotary swaging, and... 相似文献
16.
The phase transformation behavior of the metastable beta phase in hydrogen charged Ti-Mo alloys was investigated using electrical
resistivity and X-ray diffraction techniques. Hydrogen charging was found to have little effect on athermal omega phase formation
in a highly susceptible alloy (16 wt pct Mo) but suppressed athermal omega in alloys with compositions near the critical composition
for the transition to diffuse (incommensurate) type omega (∼20 wt pct Mo). No evidence was found for a hydrogen induced omega
phase in a concentrated alloy (30 wt pct Mo). The incipient stages of the beta + beta’ phase separation in Ti-30 wt pct Mo
were detected after aging slightly below the beta transus. 相似文献
17.
The phase transformation behavior of the metastable beta phase in hydrogen charged Ti-Mo alloys was investigated using electrical
resistivity and X-ray diffraction techniques. Hydrogen charging was found to have little effect on athermal omega phase formation
in a highly susceptible alloy (16 wt pct Mo) but suppressed athermal omega in alloys with compositions near the critical composition
for the transition to diffuse (incommensurate) type omega (∼20 wt pct Mo). No evidence was found for a hydrogen induced omega
phase in a concentrated alloy (30 wt pct Mo). The incipient stages of the beta + beta’ phase separation in Ti-30 wt pct Mo
were detected after aging slightly below the beta transus. 相似文献
18.
Supersaturated iron-carbon solid solutions containing 0.06, 0.18, 0.66, 2, 3, and 5 wt pct C were produced by sputter-deposition at 6° to 21°C. Homogeneous deposits of the same carbon composition as the multiphase source materials were produced by high rate (up to 0.0004 in. per hr) sputtering techniques and were 0.005 to 0.027 in. thick. The microhardnesses of the deposits were higher than the hardnesses of martensite with the same carbon content. The hardness increased rapidly from 680 Dph for 0.06 wt pct C content to an unusually high maximum of 1240 Dph at 2 wt pct C and then decreased slowly to 920 Dph at 5 wt pct C. The 0.06, 0.18, and 0.66 wt pct C deposits were bcc, and the 2 and 3 wt pct C deposits were bct. The tetragonality of the 5 wt pct C deposit was detected only after tempering at 150°C. Lattice parameterc/a ratios for the tetragonal deposits were lower than expected from extrapolated martensite data, and they corresponded to the equationc/a=1.06+0.019 (wt pct C). Nevertheless, thec/a ratio of 1.10 for 5 wt pct C deposit was higher than previously observed for martensite. No evidence of a martensitic transformation was found in the microstructures, which typically consisted of 0.5 to 1.0 μ diam columnar grains. Hardness data from tempered eposit samples and the lack of tetragonality of the low carbon deposits indicated that autotempering occurred during sputter-deposition. 相似文献
19.
Effect of phosphorus on the microstructure and stress rupture properties in an Fe-Ni-Cr base superalloy 总被引:2,自引:0,他引:2
W. R. Sun S. R. Guo D. Z. Lu Z. Q. Hu 《Metallurgical and Materials Transactions A》1997,28(3):649-654
This article describes the effect of phosphorus on the microstructure and stress rupture property at 650 °C in an Fe-Ni-Cr
base superalloy. The results showed that phosphorus markedly improved the intergranular precipitation in the range of 0.0005
to 0.016 wt pct, which facilitated M23C6 and M3B2 precipitation but inhibited the formation of MC carbide. A too high phosphorus addition (0.051 wt pct P) resulted in an excessive
precipitation at grain boundaries, while a too low phosphorus content (0.0005 wt pct P) led to many precipitate-free grain
boundaries. Phosphorus also enlarged the size of the γ′ particles and lowered its stability, that η-Ni3Ti preferred to form in the alloy with 0.051 wt pct P. Due to the improvement of the microstructure, appropriate amount of
P content significantly prolonged the rupture life of the alloys in the range of 0.0005 to 0.016 wt pct. The peak value was
660 hours at 0.016 wt pct, more than 4 times that of the alloy with 0.0005 wt pct phosphorus, but phosphorus reduced the fracture
elongation. The mechanism by which phosphorus influenced the alloy is discussed. 相似文献
20.
A. Arjuna Rao B. S. Murty M. Chakraborty 《Metallurgical and Materials Transactions A》1996,27(3):791-800
The grain-refining behavior of high purity aluminum (HPA1) and commercial purity aluminum (CPA1) containing Fe and Si as impurities
(<0.2 wt pct each) has been studied with and without the presence of Cr in small and large quantities (0.2 and 2 wt pct).
The Al-5Ti-lB master alloy ingot (0.2 wt pct) was used as a grain refiner. The emphasis was on the influence of individual
elements and their interactions with the other elements on the grain-refining behavior of Al. Good grain refinement with insignificant
fading in CPA1 was observed in comparison to HPA1. Similar results were obtained with a small concentration of Cr in HPA1
in HPA1-0.2 wt pct Cr alloy. The CPA1 and HPA1-0.2 wt pct Cr alloy have given the best grain-refining results among all the
cases studied. A combination of small quantities of Fe, Si, and Cr (CPA1-0.2 wt pct Cr) has shown early and significant fading.
A large concentration of Cr (2 wt pct) has shown a poisoning effect irrespective of the presence or absence of impurities
such as Fe and Si in Al. Thus, Cr was found to be beneficial for grain refinement at smaller concentrations in the absence
of impurities. But at higher concentrations of Cr, it had an adverse effect,i.e., led to coarser grain sizes both in the presence and absence of impurities. 相似文献