Influence Of Heat Treatment Process Research Articles

Effect of Heat Treatment Process on Microstructure and Texture of Hot-Rolled Sheet of High-Silicon Steel

The influences of heat treatment process (annealing temperature and cooling methods) on the microstructure and mechanic properties of 6.5 wt%Si steel for hot-rolled sheet products were studied by optical microscopy (OM), electron backscattered diffraction (EBSD), and microhardness tester. The results show that when the annealing temperature increases, the average grain sizes become very large similar to abnormal grain growth, but the effects of cooling methods are relatively small. The {001}〈110〉 and {112}〈110〉 textures weakened and {111}〈112〉 texture enhanced with the increase of annealing temperature. γ fiber texture is relatively high. The microhardness strengthens with increasing annealing temperature or decreasing cooling rate, which means that the plasticity weakens. Therefore, annealing temperature and cooling methods were believed to be mainly responsible for the improvement of plasticity, which may have a significant effect on the production of high-silicon steel.

Influence of heat treatment process on photocatalytic activity of photocatalyst TiO2/TiCxOy coatings during heat treatment in carbon powder

Photocatalyst TiO2/TiCxOy coatings on alumina (Al2O3) balls had been successfully fabricated by mechanical coating technique with titanium (Ti) powder and subsequent heat treatment in carbon powder. The influence of heat treatment conditions in carbon powder on the formed compounds, surface morphology and photocatalytic activity of photocatalyst TiO2/TiCxOy coatings was investigated. XRD results show that the compounds of TiCxOy and TiO2 were formed on the surface of Ti coatings during heat treatment in carbon powder. The relative amounts of TiCxOy and TiO2 remarkably varies with changing the heat treatment temperature and/or holding time. The formed nano-bump structure during heat treatment in carbon powder at 1073 or 1173 K, could increase the accessible surface area. The formation of Ti3+ and generated oxygen vacancies confirmed by XPS measurement, are in favor of narrowing band gap to enhance the visible-light photocatalytic activity of photocatalyst TiO2/TiCxOy coatings. The photocatalytic activity of the sample by heat treatment in carbon powder at 1173 K for 15 h shows highest. The fabrication strategy provides us a facile preparation procedure of visible-light responsive photocatalyst coatings.

The influence of heat treatment process on mechanical properties of surface treated volcanic ash particles/polyphenylene sulfide composites

This study primarily presents the effects of VA particle loading at various concentrations (0, 5, 10, 15, 20 and 25 wt%) on the mechanical properties of polyphenylene sulfide (PPS) composites which are determined by tensile and three‐point bending tests. After determining the optimum VA particle concentrations, surface treatment of VA particles with 3% v/v silane coupling agent (3‐aminopropyltriethoxysilane (3‐APTS)) was conducted. Similar experimental investigations were done to examine the effect of silanization on the interface region between VA particles and PPS matrix. At last, this work also determined the heat treatment (annealing) effect on the mechanical properties of surface treated VA/PPS composites. Untreated, surface treated and heat treated VA/PPS composite samples were manufactured by twin‐screw extruder and injection molding machine. All tests were performed using a Shimadzu AG‐X Universal Tester. Tensile and three‐point bending tests were carried out according to ISO 527‐2 and ASTM D790 standards, respectively. During the experiments, heat treatment and surface treatment effects on the mechanical properties VA/PPS composites were determined as a function of tensile strength and tensile modulus, flexural strength and flexural modulus. Moreover, fracture surface morphologies of VA/PPS composite samples were observed by using a scanning electron microscope. POLYM. COMPOS., 39:1604–1611, 2018. © 2016 Society of Plastics Engineers

Influence of heat treatment process in In2O3-MWCNTs as photoanode in DSSCs

Indium oxide-multi-walled carbon nanotubes (In2O3-MWCNTs) were prepared by sol-gel method for DSSCs. The synthesis of indium oxide (In2O3) was carried out by dissolving indium chloride (InCl3) in a solvent of 2-methoxyethanol. Different annealing temperatures of 400, 450, 500, 550, and 600 °C were proposed in this study. The changes in the structural properties were analyzed by means of X-ray diffraction (XRD) and atomic force microscopy (AFM) analysis. The XRD spectrum estimated the average crystallite sizes of 3 nm for each sample. AFM results indicated very rough surface area of the films where it increased linearly from 1.8 to 11 nm as the annealing temperature increases. The In2O3-MWCNTs-based DSSC exhibited good photovoltaic performance with power conversion efficiency (η), photocurrent density (J sc ), open circuit voltage (V oc ), and fill factor (FF) of 1.13 %, 5.5 mA/cm2, 0.53 V, and 0.42, respectively. Even though the film annealed at 450 °C exhibited low τ eff, it achieved the greatest D eff of 29.67 cm2 s−1 which provides an efficient pathway for the photogenerated electrons with minimum electron recombination loss that increased the J sc and V oc in the DSSC. The obtained structural and electron transport analysis was proposed as a suitable benchmark for In2O3-MWCNTs-based dye-sensitized solar cell (DSSCs) application. Hence, this study suggests that the optimum temperature for In2O3-MWCNTs is at annealing temperature of 450 °C prepared via sol-gel method.

Influence of Heat Treatment Process on the Structures and Properties of Grate Bars Used in Sintering Trolley

The as-cast structure of grate bar used in sintering trolley is primarily comprised of austenite and eutectic (eutectic austenite and eutectic carbide). The austenite is dendrite, while the carbide is reticular and chrysanthemum-like. The grate bars were quenched and tempered under various temperature (one set of samples: quenching (975~1050°C); the other: quenching (1000°C) + tempering (240~600°C)). With rise in quenching temperature, the content of martensite increases and gradually stabilizes, and the hardness increases and then decreases (the maximum is 61.5HRC). For the tempered simple, the strip-like carbides gradually become smaller, shorter and homogenized; the resistance to temper softening is high and the maximum hardness is 58HRC; the wear resistance gradually decreases and is lower than that of as-cast one when the temperature is higher than 480°C. The heat treatment process to improve the service properties of grate bars is: quenching (1000°C, 2.5h, and air-cooling) + tempering (300~420°C, 2.5h, and air-cooling).

The Effect of Heat Treatment of Gray and Nodular Cast Iron with Ferrite Matrix on Mechanical Properties and Corrosion Rate Compared with Medium Carbon Steel

In this work, the influence of heat treatment process and quenching in different quenchant media of medium carbon steel, gray and nodular cast iron with ferrite matrix on the hardness, ductility and corrosion rate of has been investigated. During this type of operations, the specimens were Austenizing at 900°C for one hour. Therefore, the specimens were quenched in different kind of oil as quenched medium (oil 20-50, oil 40, oil 90, and water as reference). The hardness , impact energy to measure the ductility, corrosion rate and microstructures were studied. From result of steel 0.47% carbon was clear increasing in hardness and decreasing in ductility with close varying values in oil quenchant kind comparing with as received specimen and water quenched one, corrosion rate decreased with heat treatment and quenching process due to formation of single face instead of double phase before heat treatment process which created galvanic cell. For gray and nodular cast iron it is noticeable that no changing in microstructure within heating for one hour at 900°C because the matrix in both cast iron types is ferrite, therefore no changing in mechanical properties under heat treatment process with time of one hour which is not sufficient to decomposition of graphite, but with comparison the hardness of gray cast iron is more than nodular one due to distribution of graphite flacks which increase the hardness and decrease the ductility as well as increasesing the corrosion rate compared with nodular cast iron. Microstructure of both types of cast iron have been studied after subjected the specimens to heat treatment at 1000°C and for 10 hours, the microstructures shown clear diffusion of some carbon in ferrite matrix around the graphite phase and under quenched some of martensite formed.

Influence of Heat Treatment Process to Advanced Steel Matrix Composites of Engineering Machinery Equipment

The steel matrix composites with 5CrNiMo steel as matrix and WC particles as hard phase, were prepared by electroslag casting technology.The microstructures of the particle reinforced steel matrix composites on the original casting state, forging and annealing state, and quenching tempering state were researched by metallographic analysis method. The results show that the most parts of the steel matrix composites, the distribution of WC particles was relatively uniform, small pore, no holes, and the material density was very high. The white WC particles wrapped around a circle of black stripe Fe3W3C and WMoC2 compound carbides. A certain thickness of transition layer organization existed on the interface of the WC particle and steel matrix, so as to improves the bonding strength of the phase interface and the strong toughness of materials.

Influence of Heat Treatment on the Microstructure and Properties of 7Cr17Mo Martensitic Stainless Steel

This paper describes the influence of heat treatment process on the microstructure and properties of a new martensitic stainless steel, which contains 0.7% carbon, 17% chromium and 1% molybdenum and can be used as kitchen knives and scissors. The microstructure and properties of the tested alloys after quenching at 980 - 1100 °C and low tempering were investigated by means of optical microscope (OM), scanning electron microscope (SEM), Rockwell hardness tester and impact tester. The results show that the microstructure consists of acicular martensite, carbides and a litter retained austenite after quenching and tempering. The carbides are mainly (Fe,Cr)23C6. The content of retained austenite increases with the increase of the quenching temperature. The solubility of carbon in martensite changes similarly. The martensite gets coarser as the quenching temperature increasing. The maximum value of hardness is 59 HRC, when the quenching temperature is 1060 °C. The impact toughness increases when the quenching temperature increases from 980 °C to 1080 °C and then decreases. The suitable heat treatment process for this alloy is quenching at 1060 °C~1080 °C for 30 min and then tempering at 200°C.

Influence of Heat Treatment Process on Tensile Fracture Behavior of Cu-Based Metallic Glass

The Cu50Zr42Al8dumbbell-shaped alloy with original scale distance of 25 mm and diameters of 4.5 mm was prepared by the suspend melting-copper mould suction casting. The structure tensile performance testing and the fracture morphology observation of Cu50Zr42Al8BMG as-quenched and 400k/1h isothermal annealing were investigated, respectively. The deformation and fracture behavior of samples had been studied. The results showed that the structure of all samples were composed of amorphous phase and possess good glass formation abilitysample as-quenched is always in the elastic deformation stage during elongation and the tensile strength is 629MPa; however ,for specimen after 400k/1h isothermal annealing ,the yield phenomenon occurs before breaking and the maximum tensile strength is 755Mpa, and the same time, the maximum failure extensibility increases from 0.56% for sample as-quenched to 0.80% for 400k/1h isothermal annealing. The fracture pattern of test sample at annealing assumes venation pattern, which is similar to fractography of Cu50Zr42Al8BMG as-quenched, in addition, which appeared apparent viscous flow behavior and melting characteristics.

Preparation and luminescent properties of Mn2 + doped glass and glass-ceramics containing LiZnPO4 nanocrystals

Fabrication of Mn2+ doped Li2O–ZnO–P2O5 phosphate glass-ceramics with a broad red emission is reported in the present work. The influence of heat treatment process on the crystallization behavior and optical properties of glasses were investigated. The results indicated that LiZnPO4 crystals precipitated in glass matrix after proper heat treatment. Compared with the glass, the red emission intensity of Mn2+ activated glass-ceramics exhibited significant enhancement. However, there is no evidence showing that Mn2+ ions exist in the LiZnPO4 crystals.

Microstructure and mechanical properties of a low carbon carbide-free bainitic steel co-alloyed with Al and Si

A low carbon, low alloy steel has been investigated for producing low carbon carbide-free bainitic microstructure by co-addition of alloying elements of aluminum and silicon. The influence of heat treatment process on microstructure, impact toughness as well as tensile properties was investigated by light optical microscopy, transmission electron microscopy, X-ray diffraction and mechanical property tests. The results demonstrate that the co-addition of aluminum and silicon in the investigated steel plays an effective role in suppressing the precipitation of cementite. A desired microstructure consisting of mainly fine-scale carbide-free bainitic ferrite and thin film-like retained austenite located between the ferrite laths was obtained and accordingly an excellent combination of toughness, ductility and strength was achieved by optimized heat treatments, i.e. by isothermal treatment at 320°C for ∼84min or more. The microstructure-mechanical property relationships are discussed.

Effect of Thermal Modification on the Physical Properties of <i>Populus ussuriensis</i>

Heat treatment is an environmental method of wood modification. The density of Populus ussuriensis, dimensional change and equilibrium moisture content change were tested through the different temperature processing, and get the influence of heat treatment process on the performance of the wood. The results show that heat treatment is an effective way to improve wood dimensional stability and shrinkage properties. With the improvement of heat treatment intensity, the equilibrium balance moisture content of wood will then gradually reduced. When treating temperature reaches 180°C above, the wood drying shrinkage properties greatly decreased, and trend to stable.

Influence of Heat Treatment Process on Properties of Polycrystalline Alumina Fiber

Polycrystalline alumina fibers were prepared by sol-gel method. The influence of heating rate on average tensile strength of fibers as well as the influence of calcining temperature on average tensile strength of fibers, crystal phases form, specific surface area of fibers were studied. The results show that when the heating rate (below 600°C) is 4°C/min,the average tensile strength of fibers over 1000Mpa The fibers pulverize obviously when the heating rate＞7°C/min. The average tensile strength and the specific surface area of fibers decreased with calcining temperature rising. When the calcining temperature reaches over 1300°C, the average tensile strength of fibers decreased quickly and the specific surface area of fibers decreases slowly for the crystalline growth.

Influence of Heat Treatment on the Microstructure and Property of Mg-Nd-Gd-Zn-Zr Alloy

Abstract The influence of heat treatment process on the microstructure and property of Mg-Nd-Gd-Zn-Zr magnesium alloy was studied. The results show that, with the increase of the solid solution temperature, the grains of the alloy grow obviously and its elongation rate is decreased, but the residual second phase in grain boundary reduces, and the fracture mode of the alloy changes from a combination of second-phase fracture and trans-grain fracture to the trans-grain cleavage fracture; with the increase of solution time, the change of the tensile strength is not evident and the elongation rate is increased, but oxidation extent tends to increasing; the double-stage ageing process can improve the elongation rate, but the tensile strength is lowered to some extent.

2729 浸炭歯車の加工と性能に関する基礎研究 : 表面形状の変化に及ぼす熱処理工程の影響(S57-1 強度,S57 伝動装置の基礎と応用)

2729 浸炭歯車の加工と性能に関する基礎研究 : 表面形状の変化に及ぼす熱処理工程の影響(S57-1 強度,S57 伝動装置の基礎と応用)

24.2: New Consideration to Annealing Process of Vacuum‐Evaporated MgO Thin Films by Cathodoluminescence Analysis

AbstractIn order to clarify the heat treatment process for Magnesium Oxide (MgO), cathodoluminescent (CL) analysis was performed. Our results in the present work prove that the heat treatment has effects on not only removing water from the surface of MgO, but also increasing density of O and Mg defect pairs. It is the first work that the influence of heat treatment process on physical properties of the vacuum evaporated MgO thin films by CL analysis.

Influence of heat treatment processes on fatigue performance of particle reinforced aluminium alloys

The fatigue performance of particle reinforced metal matrix composites improves as the matrix strength is increased. However, the heat treatment required for high matrix strength induces residual stresses into the material, which need to be balanced against potential distortion during machining of components. This paper reports results showing the fatigue behaviour of a 2124 aluminium alloy reinforced with 25 vol.-% of silicon carbide particles. The effect of quench medium on tensile and rotating bend fatigue strength is reported. Results are correlated with residual stress profiles measured in quenched plates of the material.