Microstructure and Mechanism of Three Spheroidizing Treatment for the Carbide of GCr15 Steel

2012 ◽  
Vol 476-478 ◽  
pp. 351-356 ◽  
Author(s):  
Chong Cai Zhang ◽  
Xiao Lan Yi ◽  
Qun Qun Yuan ◽  
Long Wang
Keyword(s):  
Heat Treatment ◽  
Final Heat Treatment ◽  
Tempered Martensite ◽  
Final Heat ◽  
Gcr15 Steel ◽  
Heat Treated ◽  
Spheroidizing Annealing

Three groups of GCr15 steel were heat-treated respectively by conventional spheroidizing annealing, circulation spheroidizing annealing, 1050°C for 30min oil cooling quenching + 700°C tempering. The final heat treatment of these GCr15 steel was 840°C oil cooling quenching + 150°C tempering. The microstructure of the heat-treated GCr15 were observed and the mechanism of three spheroidizing treatment were discussed in this paper. The results showed that: There is obvious difference among the three groups carbide of GCr15 for the mechanism of three spheroidizing treatments is different. The GCr15 has 1050°C for 30min oil cooling quenching + 700°C tempering showed the best result of carbide spheroidizing. The microstructure of GCr15 after 840°C oil cooling quenching + 150 °C tempering was tempered martensite and carbide which is fine, round and widely distributed.

Electrophoretic Deposition and Heat Treatment of Steel-Supported PVDF-Graphite Composite Film

2015 ◽  
Vol 761 ◽  
pp. 412-416 ◽  
Author(s):  
Kok Tee Lau ◽  
Mohd Hafrez Razi Ab Razak ◽  
Swee Leong Kok ◽  
Muhammad Zaimi ◽  
Mohd Warikh Abd Rashid ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Composite Film ◽  
Electrophoretic Deposition ◽  
Composite Films ◽  
Treatment Temperature ◽  
Final Heat Treatment ◽  
Scanning Calorimetry ◽  
Graphite Composite ◽  
Final Heat ◽  
Heat Treated

Polymeric poly (vinyliden fluoride) (PVDF) is nontoxic. It possesses a better mechanical flexibility and requires a lower synthesis temperature, as compared to the piezoceramic counterparts. In order to achieve a competitive advantage against the current piezoelectric sensor, graphite could replace a more expensive silver-palladium as the electrodes for the piezoelectric PVDF. This paper reports the preliminary results on the synthesis of steel-supported graphite-PVDF/PVDF/graphite-PVDF composite films using the two-step process, consisted of the electrophoretic deposition (EPD) and heat treatment. The composite films were characterized by means of the optical microscopy, scanning electron microscopy, X-ray diffraction and differential scanning calorimetry. The heat treated graphite-PVDF electrode deposited by EPD provides adequate mechanical strength for the subsequent depositions of pure PVDF layer and the second layer of graphite-PVDF composite electrode. However, the final heat treatment stage did not eliminate the fine and large cracks of the composite film, which might be attributed to high residue stresses and weak bonding between graphite and PVDF particles in the post-heat treated composite films. Nevertheless, the increase in final heat treatment temperature of the composite film at Stage 3 improved the graphite and PVDF grain alignment, as well as its crystallinity.

Dense and smooth epitaxial BaTiO3 thin films by the dipping-pyrolysis process

1999 ◽  
Vol 14 (2) ◽  
pp. 592-596 ◽  
Author(s):  
S. Kim ◽  
T. Fujimoto ◽  
T. Manabe ◽  
I. Yamaguchi ◽  
T. Kumagai ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Heat Treatment ◽  
Oxygen Partial Pressure ◽  
Smooth Surface ◽  
Precursor Solution ◽  
Final Heat Treatment ◽  
Pyrolysis Process ◽  
Low Oxygen ◽  
Final Heat

Dense and smooth BaTiO3 thin films were prepared on SrTiO3 (100) substrates by the dipping-pyrolysis process using a mixed precursor solution of barium and titanium naphthenates. Combination effects of prefiring [at 150–450 °C in air or low oxygen partial pressure, p(O2)[ and final heat treatment [at 850 °C in air or low p(O2)[ on preparation of BaTiO3 thin films were examined. An epitaxial BaTiO3 thin film with a dense and smooth surface consisting of nanosized grains about 70 nm was prepared by prefiring under low p(O2) at 250 °C and final heat treatment under low p (O2) at 850 °C.

Effects of Pre-Crack Depth and Hydrogen Absorption on the Failure Strain of Zircaloy-4 Cladding Tubes Under Biaxial Strain Conditions

2020 ◽  
Author(s):  
Feng Li ◽  
Takeshi Mihara ◽  
Yutaka Udagawa ◽  
Masaki Amaya
Keyword(s):  
Heat Treatment ◽  
Crack Depth ◽  
Strain Ratio ◽  
Final Heat Treatment ◽  
Fuel Cladding ◽  
Hoop Strain ◽  
Final Heat ◽  
Treatment Status ◽  
Biaxial Tensile Stress ◽  
Cold Worked

Abstract Fuel cladding may be subjected to biaxial tensile stress in axial and hoop directions during pellet-cladding mechanical interaction (PCMI) of a reactivity-initiated accident (RIA). Incipient crack in the hydride rim assisted by the scattered hydrides in the metal phase may lead to failure of the cladding at small hoop strain level during PCMI. To get insight of such phenomenon, biaxial-EDC tests under axial to hoop strain ratios ranging from 0 to 1 were performed with pre-cracked (outer surface) and uniformly hydrided Zircaloy-4 cladding tube samples with final heat-treatment status of cold worked (CW), stress relieved (SR) and Recrystallized (RX). Results showed dependencies of failure hoop strain on pre-crack depth, strain ratio, hydrogen content and final heat-treatment status on fabrication, but no apparent dependencies were observed on the distribution pattern of hydrides (with similar hydrogen contents and hydrides predominantly precipitated in hoop direction) and the heat-treatment process for hydrogen charging. J integral at failure seems to be available to unify the effect of pre-crack depth.

FABRICATION AND CHARACTERIZATION OF Ni-SHEATHED MgB2 SUPERCONDUCTING TAPES

2003 ◽  
Vol 17 (04n06) ◽  
pp. 461-467 ◽  
Author(s):  
A. MALAGOLI ◽  
G. GRASSO ◽  
A. TUMINO ◽  
M. MODICA ◽  
V. BRACCINI ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Final Heat Treatment ◽  
Superconducting Tapes ◽  
Final Heat ◽  
Nickel Tube ◽  
Preparation Route ◽  
Working Procedure ◽  
The Magnetic Field ◽  
Powder In Tube

The preparation route for Nickel-sheathed MgB2 tapes has been studied in order to achieve improved transport properties at temperatures above that of liquid helium. Superconducting tapes have been manufactured by the Powder-In-Tube method, that consists in the cold working of a Nickel tube filled by reacted MgB2 powders, and in a final heat treatment carried out in Argon atmosphere. The could working procedure has been tuned in order to achieve the highest degree of MgB2 density, while limiting the formation of sausaging of the superconducting core cross section. The effect of the final heat treatment has been studied both on the superconducting and microstructural properties of the MgB2 tapes. The critical current of the reacted MgB2 tapes has been measured as a function of the magnetic field and of the temperature on short samples as well as on a small pancake coil. Finally, the microstructural and XRD analyses have revealed the clear presence of a MgB2Ni2.5 reaction layer between the Nickel sheath and the Nickel sheath and the MgB2 superconducting core in the reacted samples.

STEM BSE imaging and Monte Carlo simulation of α-β microstructures in NbTi superconductors

1992 ◽  
Vol 50 (1) ◽  
pp. 86-87
Author(s):  
T. J. Headley ◽  
J. R. Michael ◽  
F. A. Greulich ◽  
M. J. Carr ◽  
J. M. Seuntjens
Keyword(s):  
Heat Treatment ◽  
Current Density ◽  
Volume Fraction ◽  
High Current Density ◽  
Cold Drawing ◽  
Final Heat Treatment ◽  
Two Phase ◽  
Final Heat ◽  
Pinning Properties ◽  
Image Analysis Techniques

High current density NbTi multifilamentary superconductors have α-β microstructures tailored by thermo-mechanical processing involving interspersed cold drawing and heat treatment. A final heat treatment in the two-phase α-β field controls the volume fraction of α-Ti precipitates and subsequent cold drawing refines the scale of the microstructure to a level that optimizes flux pinning properties which affect critical current density (Jc). The volume fraction, particle size, shape and spacing of α-Ti precipitates present after the final heat treatment are important parameters of interest, and should be measurable by image analysis techniques if suitable images were available.

Refractive Index Controlled Plasmon Tuning of Au Nanoparticles in SiO2-ZrO2 Film Matrices

2008 ◽  
Vol 8 (8) ◽  
pp. 3868-3876
Author(s):  
Sucheta De ◽  
Samar Kumar Medda ◽  
Goutam De
Keyword(s):  
Heat Treatment ◽  
Refractive Index ◽  
Au Nanoparticles ◽  
Sol Gel ◽  
Dip Coating ◽  
Uv Treatment ◽  
Final Heat ◽  
Molar Ratios ◽  
Glass Substrates ◽  
Heat Treated

Au-plasmon tuning has been accomplished by controlling the refractive index (n) of the embedding film matrix. The refractive index of the film matrices were controlled by changing the molar ratios of low (SiO2) and high index (ZrO2) components following sol–gel reactions. Thus, Au nanoparticles doped films were prepared from SiO2-ZrO2 inorganic–organic hybrid sols of variable molar ratios containing HAuCl4 following the dip-coating method. The film samples deposited on glass substrates were obtained after drying, UV-treatment, and subsequent heat-treatment at 500 °C in air. The nominal mol ratios of SiO2:ZrO2 were 1:0, 1:1, 1:2.3, and 1:4. 3 equivalent mol% Au–97% total oxide (SiO2 + ZrO2) was maintained in the final heat-treated films. FTIR studies confirmed good homogeneity of Si-Zr network in the Zr-containing films. The UV-treatment has been introduced to facilitate the decomposition of HAuCl4 in the hybrid matrix prior to the heat-treatment step. The main Au-plasmon peak, in the case of a SiO2 host (SiO2:ZrO2 = 1:0, n = 1.410), observed at about 546 nm, gradually red-shifted to 592 nm upon increasing the ZrO2 content (SiO2:ZrO2 = 1:4, n = 1.847). Transmission electron microscopy of the final heat-treated (500 °C) films showed existence of plate-like (triangular and hexagonal) Au nanoparticles (25–50 nm) along with relatively smaller nanoparticles of about 10 nm in size. X-ray diffraction patterns reveal that the Au nanoparticles have a (111) orientation.

Studies Concerning the Hardening Capacity of Aluminium Alloys through Heat Treatment in Electromagnetic Field

2007 ◽  
Vol 23 ◽  
pp. 201-204
Author(s):  
Maria Stoicănescu ◽  
I. Giacomelli ◽  
Maria Simona Pantelimon
Keyword(s):  
Heat Treatment ◽  
Electromagnetic Field ◽  
Aluminum Alloys ◽  
Electromagnetic Fields ◽  
Aluminium Alloys ◽  
Final Heat Treatment ◽  
Final Heat ◽  
Long Period ◽  
Hardening Process ◽  
Treatment Conditions

It is well known that the aluminum alloys containing Cu and/or Mg lead to soluble compounds which themselves allow the hardening during the process of strengthening and ageing. At the same time, the hardening process during ageing takes a relatively long period of time, and the registered rises are generally not too high. There are presented studies regarding to alloy AlCu4Mg1,5Mn which was tested in several heat treatment conditions. These alloy, after final heat treatment of hardness by and ageing, suffers a sensitive hardening – the ageing is recommended for pieces used under medium and intense mechanical stresses Using the alternative electromagnetic fields is more efficient by 10 to 12% than stationary one, not only regarding to the period of ageing, but also regarding to the highest values of hardness; Also other specific results are given in the paper.

EFFECT OF INTERMEDIATE DEFORMATION ON THE TEXTURING OF Bi-2223/Ag TAPES

2005 ◽  
Vol 19 (01n03) ◽  
pp. 295-297
Author(s):  
H. P. YI ◽  
D. LIN ◽  
X. H. SONG ◽  
W. LIU ◽  
Q. LIU ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Final Heat Treatment ◽  
Rocking Curve ◽  
Final Heat ◽  
Peak Value ◽  
Intermediate Deformation

The effect of intermediate deformation (ID) on texturing of Bi -2223 phase was studied by SEM and rocking curve. There exists a peak value for the degree of texturing as a function of ID reduction. The optimum reduction for intermediate rolling and intermediate pressing is 14.3% and 10.7%, respectively. The texturing of the Bi -2223 phase was further improved by the final heat treatment after ID. Moreover, the critical current density ( Jc ) of the tapes was directly proportional to the texturing of Bi -2223 phase.

Heat Treatment Effect on the Microstructural, Hardness and Tribological Behavior of A105 Medium Carbon Steel

2021 ◽  
Vol 406 ◽  
pp. 419-429
Author(s):  
Amel Gharbi ◽  
Khedidja Bouhamla ◽  
Oualid Ghelloudj ◽  
Chems Eddine Ramoul ◽  
Djamel Berdjane ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
High Hardness ◽  
Medium Carbon Steel ◽  
Low Friction ◽  
Tempered Martensite ◽  
Medium Carbon ◽  
Friction Resistance ◽  
Heat Treated ◽  
Low Wear

The present work is a contribution in investigating the effect of heat treatment on microstructure, hardness and friction wear of A105N steel. Samples of 25x25 mm2 cross-section and 15mm thickness have been prepared from the as-received material and then heat-treated. The samples were austenitized at 1050°C for 60 minutes followed by water quenching, then tempered at 500 and 700°C for 120 minutes. Microstructural changes and their effect on the wear resistance and hardness were investigated according to the applied heat treatments. The main results show that after quenching the structure is mostly composed of quenched martensite, which confers high hardness and friction resistance to the steel. While the tempered structure is composed of tempered martensite and ferrite. As the temperature rises to 700°C, the tempered martensite decreases and is fully transformed to ferrite and cementite. A good wear resistance expressed by a low friction coefficient and a low wear rate is achieved by tempering at 500°C.

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