scholarly journals CFD study on the validity of using PCM in a controlled cooling ceiling integrated in a ventilated room

2021 ◽  
pp. 100066
Author(s):  
Youness Khattari ◽  
Ahmed Arid ◽  
Tarik EL Rhafiki ◽  
Tarik Kousksou ◽  
Isam Janajreh ◽  
...  
Keyword(s):  
Controlled Cooling

Effects of T5 and T6 Heat Treatments Applied to Rheocast A356 Parts for Automotive Applications

2008 ◽  
Vol 141-143 ◽  
pp. 237-242 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
R. Villa
Keyword(s):  
Fatigue Behaviour ◽  
Cyclic Stress ◽  
Industrial Applications ◽  
Fatigue Tests ◽  
Controlled Cooling ◽  
Test Analysis ◽  
Heat Treated ◽  
Mechanical Performances ◽  
Semi Solid ◽  
Number Of Cycles

The correlation between the evaluation of the mechanical and of the fatigue behaviour of the rheocast, T5 and T6 heat treated SSM A356 aluminium alloy with respect to the microstructures of the component has been investigated. The study has been carried out on a suspension arm injected in a rheocasting 800 tons plant in Stampal S.p.A. The new rheocasting is a process that allows obtaining the alloys in a semisolid state directly from the liquid state, by controlled cooling of the molten alloys. The resulting microstructures are very fine, free from defects and homogeneous: these characteristics improve the mechanical properties of the alloys and specially the response to cyclic stress, an important issue for a suspension component. After a preliminary tensile test analysis, axial high frequency fatigue tests have been carried out at room temperature on specimen cut out from the suspension arm to determine the Wöhler curve and the number of cycles to failure. The results of this work allow a comparison of the effects of heat treatment process, T5 or T6, on Semi-Solid components for industrial applications in the automotive field. On the basis of these analysis the correlation between microstructure and mechanical performances can be established.

Microstructure Characteristics in Continuous Cooling Transformation of an Nb Microalloyed Steel

2011 ◽  
Vol 228-229 ◽  
pp. 72-76
Author(s):  
J. H. Yang ◽  
Q. Y. Liu
Keyword(s):  
Microalloyed Steel ◽  
Controlled Rolling ◽  
Controlled Cooling ◽  
Cooling Rates ◽  
Continuous Cooling Transformation ◽  
Microstructure Characteristics ◽  
Continuous Cooling ◽  
Nb Content ◽  
Nb Microalloyed Steel ◽  
Two Stages

Deformation dilatometry has been used to simulate controlled hot rolling followed by controlled cooling of a Nb microalloyed pipeline steels, the microstructure and transformation characteristics in the steel and the effect of deformation on transformation are studied. According to the results of both dilatometry measurements and microstructure observations, the continuous cooling transformation curves (CCT) of the tested steels are constructed. The results show that Nb content and deformation enhance the formation of acicular ferrite; the microstructure of the steel range from PF, QF to AF with increasing of cooling rates from 0.5 to 50°C /s in a two stages controlled rolling and the microstructure revolution is sensitive to cooling rates when it is lower than 5°C /s, however, when the cooling rate increasing further, the microstructure didn’t change very much but M/A constituents in matrix is refined and dispersed.

scholarly journals Mechanism of Microstructural Control and Mechanical Properties in Hot Rolled Plain C–Mn Steel during Controlled Cooling

2015 ◽  
Vol 55 (8) ◽  
pp. 1721-1729 ◽  
Author(s):  
Chengning Li ◽  
Guo Yuan ◽  
Fengqin Ji ◽  
Jian Kang ◽  
Devesh Misra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Controlled Cooling ◽  
Hot Rolled ◽  
Mn Steel ◽  
Microstructural Control

scholarly journals EFFECTIVE USE OF ROTARY FURNACE SHELL HEAT

2014 ◽  
Vol 54 (6) ◽  
pp. 414-419
Author(s):  
Julius Lisuch ◽  
Dusan Dorcak ◽  
Jan Spisak
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Raw Materials ◽  
Significant Proportion ◽  
Rotary Furnace ◽  
Cost Effective ◽  
Total Energy Expenditure ◽  
Heat Losses ◽  
Controlled Cooling ◽  
Effective Use

<pre><pre>Significant proportion of the total energy expenditure for the heat treatment of raw materials are heat losses through the shell of rotary furnace. Currently, the waste heat is not used in any way and escapes into the environment. Controlled cooling system for rotary furnace shell (<span>CCSRF</span>) is a new solution integrated into the technological process aimed at reducing the heat loss of the furnace shell. Based on simulations and experiments carried out was demonstrated a significant effect of controlled cooling shell to the rotary furnace work. The proposed solution is cost-effective and operationally undemanding.</pre></pre>

scholarly journals Comparative kinetics of the alkali-catalyzed sunflower oil methanolysis with co-solvent under conventional and microwave heating with controlled cooling

2018 ◽  
Vol 7 (5) ◽  
pp. 441-452
Author(s):  
Biljana B. Beljic Durkovic ◽  
Jelena D. Jovanovic ◽  
Borivoj K. Adnadjevic
Keyword(s):  
Microwave Heating ◽  
Sunflower Oil ◽  
Conventional Heating ◽  
Controlled Cooling ◽  
Pseudo First Order Reaction ◽  
Reaction Rate Constants ◽  
Cooling Conditions ◽  
Exponential Factors ◽  
The Impact ◽  
Kinetics Of

Abstract The kinetics of the alkali-catalyzed transesterification of sunflower oil with methanol in the presence of co-solvent (TSMPC) were investigated. The kinetics curves of the alkali-catalyzed TSMPC, in the temperature range of 26°C–55°C, were measured for conventional heating (CH) and microwave heating with controlled cooling. The results showed that for both heating modes, the kinetics of the alkali-catalyzed TSMPC reaction can be described with the kinetic model of the pseudo first-order reaction with respect to the concentration of the triglycerides. The values of apparent reaction rate constants, activation energies, and pre-exponential factors are also calculated. The existence of a linear correlation (compensation effect) between the values of apparent kinetic parameters determined for CH and microwave heating with controlled cooling conditions is established. The results confirmed that the increase in the transesterification rate in the microwave heating with controlled cooling conditions is not caused by overheating nor by the existence of hotspots. The model of mechanism of the impact of microwave heating on the kinetics of transesterification is hereby proposed.

scholarly journals Statistical Modeling of Microstructural Effects on Fatigue Behavior of α/β Titanium Alloys

2000 ◽  
Author(s):  
A. B. O. Soboyejo ◽  
S. Shademan ◽  
V. Sinha ◽  
W. O. Soboyejo
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Behavior ◽  
Statistical Correlation ◽  
Controlled Cooling ◽  
Modeling Methodology ◽  
Β Phase ◽  
Microstructural Effects ◽  
Crack Growth Rates

Abstract This paper presents the results of combined experimental and theoretical studies of the effects of colony microstructure on fatigue crack growth in Ti-6Al-4V. Colony microstructures with controlled lath widths and colony sizes are produced by controlled cooling from the β phase field. For colony microstructures with approximately 20 vol% of β phase, the fatigue crack growth rates are shown to decrease with increasing α lath and colony size. A new statistical multiparameter modeling methodology framework is proposed for the assessment of the combined effects of mechanical and microstructural random variables on the fatigue crack growth rate. Excellent statistical correlation has been observed between the theoretical model and experimental data. The implications of the results are also discussed for the estimation of fatigue life.

scholarly journals KRISTALISASI AMMONIUM PERKLORAT (AP) DENGAN SISTEM PENDINGINAN TERKONTROL UNTUK MENGHASILKAN KRISTAL BERBENTUK BULAT

2012 ◽  
Vol 9 (2) ◽  
Author(s):  
Anita Pinalia
Keyword(s):  
Ethylene Glycol ◽  
Ammonium Perchlorate ◽  
Crystal Size ◽  
Crystallization Process ◽  
Cooling System ◽  
Solid Particles ◽  
Crystal Shape ◽  
Controlled Cooling ◽  
Slow Cooling ◽  
Two Stages

AP is the solid particles with the largest composition in compossite propellant, with fractions 60-80%. Rounded particles of AP indirectly gives better performance of propellant. Therefore we need experiment the crystallization process to produce rounded AP crystal. In this experiment, crystallization was conducted by using a controlled cooling system. Cooling is done through two stages and using a different coolant. The first stage of slow cooling using water (30°C), and continued rapid cooling with ethylene glycol (-27°C). These experiment generate 45.45 kg AP with a purity 99.67%, 40 mesh crystal size, crystal shape close to round, yield 39.71%. Keywords: Ammonium perchlorate, Crystallization, Rounded crystal

scholarly journals Physical and Numerical Simulations of Closed Die Hot Forging and Heat Treatment of Forged Parts

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
Łukasz Poloczek ◽  
Łukasz Rauch ◽  
Marek Wilkus ◽  
Daniel Bachniak ◽  
Władysław Zalecki ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Numerical Simulations ◽  
Phase Transformations ◽  
Hot Forging ◽  
Transformation Model ◽  
Controlled Cooling ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Conventional Heat Treatment

The paper describes physical and numerical simulations of a manufacturing process composed of hot forging and controlled cooling, which replace the conventional heat treatment technology. The objective was to investigate possibilities and limitations of the heat treatment with the use of the heat of forging. Three steels used to manufacture automotive parts were investigated. Experiments were composed of two sets of tests. The first were isothermal (TTT) and constant cooling rate (CCT) dilatometric tests, which supplied data for the identification of the numerical phase transformation model. The second was a physical simulation of the sequence forging-cooling on Gleeble 3800, which supplied data for the validation of the models. In the numerical part, a finite element (FE) thermal-mechanical code was combined with metallurgical models describing recrystallization and grain growth during forging and phase transformations during cooling. The FE model predicted distributions of the temperature and the austenite grain size in the forging, which were input data for further simulations of phase transformations during cooling. A modified JMAK equation was used to calculate the kinetics of transformation and volume fraction of microstructural constituents after cooling. Since the dilatometric tests were performed for various austenitization temperatures before cooling, it was possible to include austenite grain size as a variable in the model. An inverse algorithm developed by the authors was applied in the identification procedure. The model with optimal material parameters was used for simulations of hot forging and controlled cooling in one of the forging shops in Poland. Distributions of microstructural constituents in the forging after cooling were calculated. As a consequence, various cooling sequences during heat treatment could be analyzed and compared.

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