scholarly journals Enhancement of the AISI 5140 Cold Heading Wire Steel Spheroidization by Adequate Control of the Initial As-Rolled Microstructure

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 219
Author(s):  
Jon Arruabarrena ◽  
Jose M. Rodriguez-Ibabe
Keyword(s):  
Annealing Treatment ◽  
Cold Forming ◽  
Initial Microstructure ◽  
Fault Migration ◽  
Ferrite Lath ◽  
Subcritical Annealing ◽  
Upper Bainite ◽  
Wire Steel ◽  
Fine Pearlite ◽  
Subcritical Treatment

The effect of the initial microstructure and soft annealing temperature on cementite spheroidization and microstructure softening is studied on an AISI 5140 hot-rolled wire. In coarse pearlite microstructure (λ: 0.27 μm), the cementite spheroidization progresses slowly under subcritical treatment, and the microstructure does not achieve the minimum G2/L2 IFI rating defined in the ASTM F2282 to be used in cold forming operations under any of the annealing treatment studies. Fine pearlite (λ: 0.10 μm) and upper bainite microstructures are more prone to spheroidization, and the minimum G2/L2 IFI rating is achieved under subcritical annealing at 720 °C for 6 h. Independent of the initial microstructure, even in the case of martensite, low hardness values within 165–195 HV are attained after imposing a 10 h long treatment at 720 °C. Annealing treatments conducted at 660 °C and 600 °C on pearlitic microstructures give rise to very poor softening. The G2/L2 rating is not achieved in any of the treatments applied at these two temperatures in this study. In pearlitic microstructures, the spheroidization progresses according to a fault migration mechanism, enhanced by the presence of defects such as lamella terminations, holes, and kinks. In the upper bainite, the row-like disposition of the cementite along the ferrite lath interface provides necks where dissolution and consequent lamellae break-up take place quickly under annealing.

Effect of Initial Microstructure on Properties of Cryorolled Al 5052 Alloy Subjected to Different Annealing Treatment Temperatures

2018 ◽  
Vol 27 (11) ◽  
pp. 6206-6217 ◽  
Author(s):  
N. M. Anas ◽  
B. K. Dhindaw ◽  
H. Zuhailawati ◽  
T. K. Abdullah ◽  
A. S. Anasyida
Keyword(s):  
Annealing Treatment ◽  
Initial Microstructure ◽  
Al 5052 Alloy

scholarly journals New Design of Copper–Inconel 601 Ground Electrode Spark Plug Based on a Thermo-Mechanical Model

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3798
Author(s):  
Chawki Tahri ◽  
Helmut Klocker ◽  
Bernard Beaugiraud ◽  
Christophe Bertoni ◽  
Eric Feulvarch ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Model ◽  
Detrimental Effect ◽  
Protective Coatings ◽  
Annealing Treatment ◽  
Mechanical Analysis ◽  
Electrode Design ◽  
Cold Forming ◽  
Spark Plug ◽  
Scanning Electron

Inconel 601 is one material of choice for intermediate- to high-temperature protective coatings for spark plugs’ ground electrodes. Production of ground electrodes of spark plugs implies the following operations: the tamping of the copper core in an Inconel 601 cup, cold-forming of the assembly, annealing, welding, and bending of the final spark plug. On the production line, the use of Inconel 601 as a protective coating for ground electrodes leads to possible cracking in the welded area after bending. In the present paper, possible causes of cracking are analyzed. It is clearly shown that a combination of Copper –Inconel interface oxidation, Inconel yielding during the heat treatment, and micro-movements during bending lead to cracks in the welded area of the ground electrode. First, the detrimental effect of gaps, between Copper and Inconel 601, is shown experimentally. Second, a thermo-mechanical analysis combined with SEM (Scanning Electron Microscopy) observations identified the annealing treatment and interface oxidation as the main cause of gaps. Third, bending simulations show the relation between these gaps and cracking. Finally, a new ground electrode design, preventing cracks, is suggested.

Morphological transformations in solution-cast Styrene-Butadiene-Styrene (SBS) triblock copolymer thin films

1995 ◽  
Vol 53 ◽  
pp. 184-185
Author(s):  
Ginam Kim ◽  
W. Marsillo ◽  
M. Libera
Keyword(s):  
Thin Films ◽  
Triblock Copolymer ◽  
Annealing Treatment ◽  
Minor Component ◽  
Solvent Evaporation ◽  
Single Crystal Substrate ◽  
Transparent Films ◽  
Crystal Substrate ◽  
Solution Cast ◽  
Morphological Transformations

The fact that block copolymers can assume a range of morphologies depending upon such variables as relative block length and molecular weight is now well known. In the case of poly(styrene)[PS]-poly(butadiene)[PB]-poly(styrene) (SBS) triblock copolymer, the morphologies range from spheres (roughly ~20% minor component), to cylinders (roughly 20%~35% minor component), to lamellae (roughly equal component fractions) Most recently, there has been increasing interest in transformations between morphologies by thermal annealing. This paper describes initial results studying the effect of solvent evaporation rate and post-casting annealing treatment on the morphology of SBS thin films.TEM specimens were prepared by solution casting electron transparent films. 50 μl of 0.1 wt% SBS (30% styrene, Mw=14,000, Scientific Polymer Products, Inc.) dissolved in toluene was deposited on a polished NaCl single crystal substrate placed in a small dish. After solvent evaporation the film was cut into small squares, floated from the salt in water, and each square was collected on a Cu grid.

The microstructure change of low-carbon electrical steels by residual aluminum

1989 ◽  
Vol 47 ◽  
pp. 286-287
Author(s):  
C.K. Hou ◽  
C.T. Hu ◽  
Sanboh Lee
Keyword(s):  
Annealing Treatment ◽  
Low Carbon ◽  
Electrical Steels ◽  
Vacuum Degassing ◽  
Spherical Inclusions ◽  
Residual Aluminum ◽  
Average Grain Size ◽  
The Matrix ◽  
Fine Size ◽  
To Come

The fully processed low-carbon electrical steels are generally fabricated through vacuum degassing to reduce the carbon level and to avoid the need for any further decarburization annealing treatment. This investigation was conducted on eighteen heats of such steels with aluminum content ranging from 0.001% to 0.011% which was believed to come from the addition of ferroalloys.The sizes of all the observed grains are less than 24 μm, and gradually decrease as the content of aluminum is increased from 0.001% to 0.007%. For steels with residual aluminum greater than 0. 007%, the average grain size becomes constant and is about 8.8 μm as shown in Fig. 1. When the aluminum is increased, the observed grains are changed from the uniformly coarse and equiaxial shape to the fine size in the region near surfaces and the elongated shape in the central region. SEM and EDAX analysis of large spherical inclusions in the matrix indicate that silicate is the majority compound when the aluminum propotion is less than 0.003%, then the content of aluminum in compound inclusion increases with that in steel.

Characterisation of planar crystal defects in Y2Fe17Cx (0.6 ≤ x ≤ 1.6) magnetic material by High Resolution Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 774-775
Author(s):  
W. Coene ◽  
F. Hakkens ◽  
T.H. Jacobs ◽  
K.H.J. Buschow
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Permanent Magnets ◽  
Annealing Treatment ◽  
High Resolution Electron Microscopy ◽  
Crystal Defects ◽  
Ordered Structure ◽  
X Ray ◽  
Planar Crystal ◽  
Resolution Electron

Intermetallic compounds of the type RE2Fe17Cx (RE= rare earth element) are promising candidates for permanent magnets. In case of Y2Fe17Cx, the Curie temperature increases from 325 K for x =0 to 550 K for x = 1.6 . X ray and electron diffraction reveal a carbon - induced structural transformation in Y2Fe17Cx from the hexagonal Th2Ni17 - type (x < 0.6 ) to the rhombohedral Th2Zn17 - type ( x ≥ 0.6). Planar crystal defects introduce local sheets of different magnetic anisotropy as compared with the ordered structure, and therefore may have an important impact on the coercivivity mechanism .High resolution electron microscopy ( HREM ) on a Philips CM30 / Super Twin has been used to characterize planar crystal defects in rhombohedral Y2Fe17Cx ( x ≥ 0.6 ). The basal plane stacking sequences are imaged in the [100] - orientation, showing an ABC or ACB sequence of Y - atoms and Fe2 - dumbbells, for both coaxial twin variants, respectively . Compounds resulting from a 3 - week annealing treatment at high temperature ( Ta = 1000 - 1100°C ) contain a high density of planar defects.

TEM study of buried cobalt disilicide layers formed by ion implantation: Identification of cobalt monosilicide inclusions

1990 ◽  
Vol 48 (4) ◽  
pp. 576-577
Author(s):  
A. De Veirman ◽  
J. Van Landuyt ◽  
K.J. Reeson ◽  
R. Gwilliam ◽  
C. Jeynes ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Annealing Treatment ◽  
Silicon On Insulator ◽  
High Dose ◽  
Nitrogen Flow ◽  
Cobalt Disilicide ◽  
Transmission Electron ◽  
Beam Heating ◽  
Co Concentration ◽  
Silicon On Insulator Technology

In analogy to the formation of SIMOX (Separation by IMplanted OXygen) material which is presently the most promising silicon-on-insulator technology, high-dose ion implantation of cobalt in silicon is used to synthesise buried CoSi2 layers. So far, for high-dose ion implantation of Co in Si, only formation of CoSi2 is reported. In this paper it will be shown that CoSi inclusions occur when the stoichiometric Co concentration is exceeded at the peak of the Co distribution. 350 keV Co+ ions are implanted into (001) Si wafers to doses of 2, 4 and 7×l017 per cm2. During the implantation the wafer is kept at ≈ 550°C, using beam heating. The subsequent annealing treatment was performed in a conventional nitrogen flow furnace at 1000°C for 5 to 30 minutes (FA) or in a dual graphite strip annealer where isochronal 5s anneals at temperatures between 800°C and 1200°C (RTA) were performed. The implanted samples have been studied by means of Rutherford Backscattering Spectroscopy (RBS) and cross-section Transmission Electron Microscopy (XTEM).

Preparation of pearlitic steels for cold forming

2019 ◽  
Vol 0 (11) ◽  
pp. 38-42
Author(s):  
A.A. Filippov ◽  
◽  
G.V. Pachurin ◽  
N.A. Kuzmin ◽  
T.V. Nuzhdina ◽  
...  
Keyword(s):  
Cold Forming

STRENX 960MC

Alloy Digest ◽  
2016 ◽  
Vol 65 (11) ◽  
Keyword(s):  
Yield Strength ◽  
Physical Properties ◽  
Structural Steel ◽  
Tensile Properties ◽  
Bend Strength ◽  
Cold Forming ◽  
Hot Rolled ◽  
Minimum Yield

Abstract Strenx 960MC is a hot-rolled structural steel made for cold forming, with minimum yield strength of 960 MPa (139 ksi) for stronger and lighter structures. This alloy meets or exceeds the requirements of S960MC in EN 10149-2. This datasheet provides information on composition, physical properties, tensile properties, and bend strength. It also includes information on surface qualities as well as forming, machining, and joining. Filing Code: SA-772. Producer or source: SSAB Swedish Steel Inc..

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