scholarly journals The Influence of Annealing Temperature and Soaking Time on the Ductility of SG 255

2017 ◽  
Vol 2 (3) ◽  
pp. 361-364 ◽  
Author(s):  
Fryad J. Mahmud ◽  
Kawan M. Abdulrahman ◽  
Hawkar J. Muhammed ◽  
Barzan A. H. Seed

This study deals with the effect of annealing temperature on the mechanical properties of SG 255 steel. Furthermore it aims to experimentally obtain better mechanical properties in particular ductility with lower annealing temperature and to minimize the cost of the manufacturing. The SG 255 steel is used in manufacturing of domestic LPG cylinder at Halala Company located in Sulaimanyah/Iraq. A number of samples were made according to ISO 6892, and then heat treated with different annealing temperature (850, 900 and 950 ºC). Moreover, the mentioned samples were broken by tensile machine to obtain the required mechanical properties, and to be compared with that of Halala factory. It was shown that higher elongation percentage 34.18%El with lower annealing temperature 900 ºC can be achieved and this leads to decrease the cost of manufacturing without degrading of cylinder’s quality.

2017 ◽  
Vol 750 ◽  
pp. 103-106
Author(s):  
Charnnarong Saikaew ◽  
Worakarn Sawatwor

Many researchers have studied the effects of heat treating processes on mechanical properties, corrosion and wear resistance of various martensitic stainless steels. It is crucial to comprehensively understand the role of heat treating processes on the mechanical properties of the steels with a systematic approach. In this work, the specimens were heat treated by preheating in two steps before continuing the heating to the quench temperature. The first preheating was performed in the furnace maintained at 400 °C for 5 min. The second step was done in the furnace kept at 800 °C for 5 min. Then the specimens were heated directly to the hardening temperature, 1030 °C. The specimens reached 1030 °C for a sufficient time of 30 min to form austenite and to allow enough of the carbides to be dissolved to ensure the desired combination of hardness and toughness. After hardening time was over, the specimens were quenched in water to form martensite for 2-8 s and holding in the air for 4 s, followed with water quenching for 2-8 s and cooling to room temperature. Data was collected in order to perform one-way analysis of variance (ANOVA). In this study, the ANOVA consisted of four levels of soaking time of 2, 4, 6 and 8 s and holding time of 4 s. All heat-treated specimens were then used to perform hardness and Charpy-V-Notch impact tests. The results showed that the hardness values increased with increasing of soaking time. The impact energy value slightly decreased with the soaking time range of 2-4 s whereas it rapidly decreased with the soaking time range of 4-6 s and slightly increased with the range of 6-8 s. However, the results from ANOVA showed that the soaking time did not significantly affect the averages hardness and impact energy at the level of significance of 0.05.


2017 ◽  
Vol 36 (3) ◽  
pp. 223-232 ◽  
Author(s):  
H. R. Ren ◽  
L. Guo ◽  
Z. C. Guo

AbstractThe plasticity, elastic modulus and thermal stability restrict the applications of electrodeposited nanocrystalline Ni-Fe alloy foils. To improve its mechanical properties, the electrodeposited Ni-Fe alloy foils were heat treated within the temperature 900–1,150 °C. The microstructure and texture of the samples were further analyzed with a combination of SEM, XRD and EBSD. The experimental results indicated that the electrodeposited Ni-Fe alloy foil had poor mechanical properties at about 1,000 °C, which was mainly attributed to the development of a mixed grain microstructure. At 900–950 °C, the plastic and elastic modulus were greatly improved, which were owed to the uniformed microstructure and the decrease of structure defects. At 1,050–1,150 °C, the degree of the mixed grain microstructure decreased, resulting in improved plasticity and higher elastic modulus. However, the strength of the foil obviously decreased, which was mainly associated with the increase of the average grain size.


2019 ◽  
Vol 95 ◽  
pp. 04003
Author(s):  
Ruangyot Wichienrak ◽  
Somchai Puajindanetr

Cold rolled steel industry in type of batch annealing furnace, the mechanical properties of steel sheet have variation by each position. The parameters of annealing temperature and time were analysed to work out the source of mechanical properties variation. This experiment is using low-carbon steel sheet that were cold rolled at the same reduction ratio. Then annealed applying by different annealing temperature and soaking time in laboratory furnace. The mechanical properties which were examined. Yield strength, Tensile strength, %Elongation and Hardness. The result showed that (1) Increasing the annealing temperature could remarkably decrease the yield strength, tensile strength and hardness, whereas the %Elongation could be increased. (2) Increasing the soaking time could slightly effect on mechanical properties. (3) The annealing temperature of 650°C with soaking time of 2 hr should be applied to provide the mechanical properties close to target value (4) Grain size of the workpieces trended to be grown from the annealing temperature of 610°C.The experiment it can be concluded that annealing temperature and soaking time have significant effect on the mechanical properties variation in batch annealing.


Author(s):  
Shusaku Takagi ◽  
Hiroshi Okano ◽  
Akihide Nagao

Evaluations of mechanical properties under high pressure hydrogen gas environments are difficult because special testing equipment which can obtain data under high pressure hydrogen gas is necessary and the cost of installing those machines is very high. Therefore, a method for predicting mechanical properties under high pressure hydrogen gas without special equipment was investigated in this study. A JIS SCM435 steel, of which the typical chemical composition is Fe-0.35%C-0.2%Si-0.75%Mn-1.1%Cr-0.2%Mo, was used. Material with the size of 22mm in square and 200mm in length was heat-treated by quenching in oil and tempering, followed by water cooling. The material microstructure was tempered martensite, and the tensile strength of the steel was about 1000MPa. The fatigue property was evaluated in cathodic hydrogen charging service and high pressure hydrogen gas service. The fatigue property obtained by the cathodic charging method was almost the same as the property under the high pressure hydrogen gas condition. The reason is conjectured to be that the hydrogen fugacity on the specimen surface and the surface state of the specimen under those test services was substantially the same.


Author(s):  
Michael M. Kersker ◽  
E. A. Aigeltinger ◽  
J. J. IIren

Ni-rich alloys based on approximate ternary composition Ni-8Mo-15A1 (at%) are presently under investigation in an attempt to study the contribution, if any, of the profusion of Mo-rich NixMo metastable compounds that these alloys contain to their excellent mechanical properties. One of the alloys containing metastable NixMo precipitates is RSR 197 of composition Ni-8.96Mo-15.06A1-1.98Ta-.015Yt. The alloy was prepared at Pratt and Whitney Government Products Division, West Palm Beach, Florida, from rapidly solidified powder. The powder was canned under inert conditions and extruded as rod at 1315°C. The as-extruded rod, after air cooling, was solution treated at 1315°C for two hours, air cooled, and heat treated for one hour at 815°C, followed again by air cooling.


Author(s):  
N.Z. Hafizah ◽  
J. M. Juoi ◽  
M.R. Zulkifli ◽  
M.A. Musa

The synthesis of Ag-TiO2 coating using AgNO3 precursor is expected to give the properties as pure as Ag nanoparticles. Commonly, high concentration of Ag attributed to agglomeration of silver species and reduction to Ag0 particles on TiO2 surface. In contrast, at lower concentration, Ag species exist as AgO, Ag2O and Ag0. Hence, the exact amount of Ag, which can effectively control the particle growth and agglomeration, surface area, thermal stability and band gap of the TiO2 coating, are still vague and stated differently. In the present study, the effect of Ag content on the phase transformation and surface morphology of Ag-TiO2 coating were reported. TiO2 sol were prepared by incorporating Ag at 2.5, 5 and 7.5 mol % and deposited on unglazed ceramic tiles thru five times dip coating. The deposited Ag-TiO2 coatings were heat treated at 500 °C for 1 hour soaking time. XRD analyses revealed that the deposited Ag-TiO2 coating consists of anatase, rutile, Ag2O and metallic Ag. Almost all the coating surfaces illustrated cracks. Increased Ag content lead to presence of tiny particles on the surfaces and EDX spectrum revealed the presence of Ti, O and metallic Ag particles. However, at the addition of 5 mol % Ag, there was no metallic Ag presence and a dense coating with the lowest thickness of ±11.4µm is observed.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 476
Author(s):  
Sayed Amer ◽  
Ruslan Barkov ◽  
Andrey Pozdniakov

Microstructure of Al-Cu-Yb and Al-Cu-Gd alloys at casting, hot-rolled -cold-rolled and annealed state were observed; the effect of annealing on the microstructure was studied, as were the mechanical properties and forming properties of the alloys, and the mechanism of action was explored. Analysis of the solidification process showed that the primary Al solidification is followed by the eutectic reaction. The second Al8Cu4Yb and Al8Cu4Gd phases play an important role as recrystallization inhibitor. The Al3Yb or (Al, Cu)17Yb2 phase inclusions are present in the Al-Cu-Yb alloy at the boundary between the eutectic and aluminum dendrites. The recrystallization starting temperature of the alloys is in the range of 250–350 °C after rolling with previous quenching at 590 and 605 °C for Al-Cu-Yb and Al-Cu-Gd, respectively. The hardness and tensile properties of Al-Cu-Yb and Al-Cu-Gd as-rolled alloys are reduced by increasing the annealing temperature and time. The as-rolled alloys have high mechanical properties: YS = 303 MPa, UTS = 327 MPa and El. = 3.2% for Al-Cu-Yb alloy, while YS = 290 MPa, UTS = 315 MPa and El. = 2.1% for Al-Cu-Gd alloy.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1409
Author(s):  
Ofelia Durante ◽  
Cinzia Di Giorgio ◽  
Veronica Granata ◽  
Joshua Neilson ◽  
Rosalba Fittipaldi ◽  
...  

Among all transition metal oxides, titanium dioxide (TiO2) is one of the most intensively investigated materials due to its large range of applications, both in the amorphous and crystalline forms. We have produced amorphous TiO2 thin films by means of room temperature ion-plasma assisted e-beam deposition, and we have heat-treated the samples to study the onset of crystallization. Herein, we have detailed the earliest stage and the evolution of crystallization, as a function of both the annealing temperature, in the range 250–1000 °C, and the TiO2 thickness, varying between 5 and 200 nm. We have explored the structural and morphological properties of the as grown and heat-treated samples with Atomic Force Microscopy, Scanning Electron Microscopy, X-ray Diffractometry, and Raman spectroscopy. We have observed an increasing crystallization onset temperature as the film thickness is reduced, as well as remarkable differences in the crystallization evolution, depending on the film thickness. Moreover, we have shown a strong cross-talking among the complementary techniques used displaying that also surface imaging can provide distinctive information on material crystallization. Finally, we have also explored the phonon lifetime as a function of the TiO2 thickness and annealing temperature, both ultimately affecting the degree of crystallinity.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan

This study evaluated the microstructure, grain size, and mechanical properties of the alloy 800H rotary friction welds in as-welded and post-weld heat-treated conditions. The standards for the alloy 800H not only specify the composition and mechanical properties but also the minimum grain sizes. This is because these alloys are mostly used in creep resisting applications. The dynamic recrystallization of the highly strained and plasticized material during friction welding resulted in the fine grain structure (20 ± 2 µm) in the weld zone. However, a small increase in grain size was observed in the heat-affected zone of the weldment with a slight decrease in hardness compared to the base metal. Post-weld solution heat treatment (PWHT) of the friction weld joints increased the grain size (42 ± 4 µm) in the weld zone. Both as-welded and post-weld solution heat-treated friction weld joints failed in the heat-affected zone during the room temperature tensile testing and showed a lower yield strength and ultimate tensile strength than the base metal. A fracture analysis of the failed tensile samples revealed ductile fracture features. However, in high-temperature tensile testing, post-weld solution heat-treated joints exhibited superior elongation and strength compared to the as-welded joints due to the increase in the grain size of the weld metal. It was demonstrated in this study that the minimum grain size requirement of the alloy 800H friction weld joints could be successfully met by PWHT with improved strength and elongation, especially at high temperatures.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 968
Author(s):  
Dong Xing ◽  
Xinzhou Wang ◽  
Siqun Wang

In this paper, Berkovich depth-sensing indentation has been used to study the effects of the temperature-dependent quasi-static mechanical properties and creep deformation of heat-treated wood at temperatures from 20 °C to 180 °C. The characteristics of the load–depth curve, creep strain rate, creep compliance, and creep stress exponent of heat-treated wood are evaluated. The results showed that high temperature heat treatment improved the hardness of wood cell walls and reduced the creep rate of wood cell walls. This is mainly due to the improvement of the crystallinity of the cellulose, and the recondensation and crosslinking reaction of the lignocellulose structure. The Burgers model is well fitted to study the creep behavior of heat-treated wood cell walls under different temperatures.


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