The Experts below are selected from a list of 1620 Experts worldwide ranked by ideXlab platform
K. Narayan Prabhu - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Cooling Behaviour of Carbon Steels in Polymer, Oil and Carbonated Quench Media
Transactions of the Indian Institute of Metals, 2019Co-Authors: Nidhin George Mathews, U. Vignesh Nayak, K. Narayan PrabhuAbstract:Cooling behaviour of steels in quench media is of great importance as this controls phase transformations, heat transfer and the stress evolution. The heat extraction ability of each quenchant is different because of varying thermophysical properties and wetting behaviour. The Quenchants should be selected in such a way that they provide uniform cooling of steel. In the present investigation, quenching experiments were carried out with Inconel 600, EN19, EN24, EN31 steel grades in distilled water, servo oil, carbonated distilled water and 10% PAG. The cooling curve analysis of the quenching process was carried out with temperature data recorded during quenching. This measured temperature–time data were used to estimate the heat flux by inverse modelling without considering the effect of phase transformation. The crack propensity was quantified using the quench uniformity ratio. The hardness distribution observed during quenching in carbonated distilled water was observed to be more uniform compared to other quench media.
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Carbonated aqueous media for quench heat treatment of steels
Journal of Materials Engineering and Performance, 2016Co-Authors: U. Vignesh Nayak, K. Narayan PrabhuAbstract:Distilled water and polyalkylene glycol (PAG)-based aqueous Quenchants of 5 and 10 vol.% with and without carbonation were prepared and used as heat transfer media during immersion quenching. Cooling curves were recorded during quenching of an inconel 600 cylindrical probe instrumented with multiple thermocouples. It was observed that the vapor stage duration was prolonged and the wetting front ascended uniformly for quenching with carbonated media. The cooling data were analyzed by determining the critical cooling parameters and by estimating the spatially dependent probe/quenchant interfacial heat flux transients. The study showed significantly reduced values of heat transfer rate for carbonated Quenchants compared to Quenchants without carbonation. Further, the reduction was more pronounced in the case of PAG-based carbonated Quenchants than carbonated distilled water. The results also showed the dependence of heat transfer characteristics of the carbonated media on polymer concentration. The effect of quench uniformity on the microstructure of the material was assessed.
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Wetting Kinetics and Cooling Performance of PAG Polymer Quenchants
Materials Science Forum, 2015Co-Authors: U. Vignesh Nayak, K. Narayan PrabhuAbstract:The present research work is aimed at the estimation of quench severity Polyalkylene Glycol (PAG) polymer Quenchants having varying concentrations. An Inconel600 probe instrumented with thermocouples was used for this purpose. The thermal history at various locations in the probe was used as an input to the inverse heat conduction model. The inverse analysis yields spatially dependent heat flux transients. The quench severity was assessed using the Grossmann technique. The wetting kinematics of quenching was studied by cooling curve analysis. The severity of quenching as measured by the Grossmann’s technique was found to be higher for polymer Quenchants. However, the heat flux transients estimated by the inverse technique and rewetting times measured form the cooling curve analysis suggested comparable and uniform heat transfer with polymer Quenchants compared to water Quenchants.
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Effect of thermal conductivity and viscosity on cooling performance of liquid quench media
International Heat Treatment & Surface Engineering, 2013Co-Authors: G. Ramesh, K. Narayan PrabhuAbstract:AbstractIn this present work, the effect of the thermophysical properties of Quenchants on its cooling performance was investigated. Water, brine solutions, polymer solutions and mineral oils were chosen to have quench media with varying thermophysical properties. Cooling curve analyses were carried out by using standard ISO/DIS 9950 quench probe. Grossmann H quench severity of the quench media was determined from the relation of H and cooling rate. Cooling curve analysis results showed that the change in thermophysical properties of the quench media had significant effect on the cooling history of the quench probe. The viscosity of the quenchant used for immersion quenching is the most important factor that controls the cooling performance of the quenchant compared to thermal conductivity of the quench medium.
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Effect of surface roughness on metal/quenchant interfacial heat transfer and evolution of microstructure
Materials & Design, 2007Co-Authors: K. Narayan Prabhu, Peter FernandesAbstract:Abstract In the present work, the effect of surface roughness on heat transfer rates in various Quenchants was determined. The heat flux transients at the probe/quenchant interface were estimated by inverse modeling of heat conduction during end quenching of stainless steel probes with three different surface roughness (grooved, R a = 3.0 and 1 μm). Heat transfer during quenching was correlated with the hardness obtained for medium carbon AISI 1060 steel specimens. The effect of surface roughness on heat transfer rate during quenching in water and brine was significant for rough surface whereas its effect on heat transfer rate is only marginal in high viscosity oil Quenchants. A fully martensitic structure was observed with grooved surface subjected to water quenching. With a smooth surface a mixed microstructure was obtained. The oil quenched specimens were found to be less sensitive to surface roughness.
George E Totten - One of the best experts on this subject based on the ideXlab platform.
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Vegetable oil Quenchants: a review
International Journal of Microstructure and Materials Properties, 2019Co-Authors: Rosa Lucia Simencio Otero, Lemmy Meekisho, Lauralice De Campos Franceschini Canale, George E TottenAbstract:For thousands of years, vegetable oils have been used as cooling media to heat treat metals. However, the motivation for employing Quenchants formulated with biodegradable, non-toxic and renewable base stocks has seen significant increase due to the environmental appeal to replace petroleum based Quenchants. This paper presents an overview of the main aspects and characteristics of vegetable oils that directly influence their commercial application such as structure, classification, biodegradability and toxicity, quenching properties, oxidation and inhibition, and wetting. Further, some applications of vegetable oils as Quenchants will be discussed here.
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Assessment of Cooling and Heat Transfer Properties of Quenchants with MATLAB
Materials Performance and Characterization, 2018Co-Authors: Lemmy Meekisho, George E Totten, Rosa Lucia Simencio Otero, Jônatas M. Viscaino, D. Scott Mackenzie, Lauralice De Campos Franceschini CanaleAbstract:There is ongoing interest for evaluating the potential of renewable base stocks, such as vegetable oils, to replace petroleum oils as metal Quenchants. Perhaps the most critical part of this process is characterizing and comparing the cooling and heat transfer performance of potential quenchant candidates. In this work, cooling curves of two vegetable oils, palm oil and canola oil, were obtained along with a commercially available conventional and an accelerated petroleum quenchant using the so-called Tensi multiple thermocouple probe, with emphasis on the center probe emulating a small probe concept. The lumped-parameter approach was implemented in the MATLAB environment (Mathworks Inc., Natick, MA). Experimental quenching data along with temperature-dependent thermal properties for the Inconel probe material were used to quantify the cooling characteristics and heat transfer properties of two typical vegetable and petroleum oil Quenchants. The results obtained exhibited a fundamental difference in the cooling characteristics between the vegetable oils and also between both vegetable oils and the petroleum oil Quenchants evaluated. The focus of this article will be on the development of the computational codes and the use of MATLAB to perform these analyses.
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Vegetable Oils as Metal Quenchants: A Comprehensive Review
Materials Performance and Characterization, 2017Co-Authors: R. L. Simencio Otero, George E Totten, L C F Canale, Lemmy MeekishoAbstract:There is an ongoing interest in the development and use of renewable base stocks to formulate Quenchants. The most common criterion of vegetable oils as renewable base stocks is their biodegradability and that they be non-toxic. A comprehensive overview of all aspects of vegetable oils that impacts their potential for commercial use is provided. Topics discussed include: vegetable oil structure, processing, physical properties, classification, biodegradation and toxicity; oxidation and inhibition; wetting and wetting kinematics; and applications. As a class, vegetable oil-based quenchant formulations reported in the literature to date exhibit a number of disadvantages, the most notable being their relatively poor thermal-oxidative stability in comparison with petroleum oil-based Quenchants in use. Potential pathways to vegetable oil-based fluid compositions that may rival the thermal-oxidative stability of many petroleum oil-based Quenchants were introduced.
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COMPARATIVE MEASUREMENT OF THE Quenchants WITH LIŠČIĆ/PETROFER AND ASTM D6200 PROBES
2017Co-Authors: Božidar Matijević, George E Totten, L C F Canale, Ljiljana PedišićAbstract:For evaluation of Quenchants under real industrial conditions, the new Liscic/Petrofer probe is designed. Liscic/Petrofer is special upon design, because it is instrumented with 3 thermo-couples on the same radius of the cross-section at the middle of the probe length. The outer thermocouple measures the temperature at 1 mm below surface, the second one at 4.5 mm below surface, and the third one at the center of the probe. The working principle of the probe is the measurement of the dynamics of heat extraction which is best represented by the change of temperature gradients. Second type of probe developed to evaluate the cooling properties of relatively small samples of a quenchant used in this paper is standard ASTM D6200 probe, which consists from cylindrical test specimen having one thermocouple at its geometrical center. Comparative testing was recently performed with the Liscic/Petrofer probe and standard probe with one vegetable oil (Palm Oil) and a commercially available conventional mineral oil (Kalenol 32). The work was performed at the Quenching Research Centre (QRC) of the Faculty for Mechanical Engineering, University of Zagreb, Croatia. The results of this paper showed distinctive differences in the quenching behavior of these two quenchant media. The results of this comparative study are reported herein.
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comparative measurement of the Quenchants with liscic petrofer and astm d6200 probes
50th LUBRICANTS AND BASE OILS SYMPOSIUM, 2017Co-Authors: Božidar Matijevic, George E Totten, L C F Canale, Ljiljana PedisicAbstract:For evaluation of Quenchants under real industrial conditions, the new Liscic/Petrofer probe is designed. Liscic/Petrofer is special upon design, because it is instrumented with 3 thermo-couples on the same radius of the cross-section at the middle of the probe length. The outer thermocouple measures the temperature at 1 mm below surface, the second one at 4.5 mm below surface, and the third one at the center of the probe. The working principle of the probe is the measurement of the dynamics of heat extraction which is best represented by the change of temperature gradients. Second type of probe developed to evaluate the cooling properties of relatively small samples of a quenchant used in this paper is standard ASTM D6200 probe, which consists from cylindrical test specimen having one thermocouple at its geometrical center. Comparative testing was recently performed with the Liscic/Petrofer probe and standard probe with one vegetable oil (Palm Oil) and a commercially available conventional mineral oil (Kalenol 32). The work was performed at the Quenching Research Centre (QRC) of the Faculty for Mechanical Engineering, University of Zagreb, Croatia. The results of this paper showed distinctive differences in the quenching behavior of these two quenchant media. The results of this comparative study are reported herein.
Weimin Zhang - One of the best experts on this subject based on the ideXlab platform.
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doi:10.4028/www.scientific.net/SSP.118.227 The Effects of Probe Geometric Shape on the Cooling Rate Curves Obtained from Different Quenchants
2014Co-Authors: Nailu Chen, Weimin Zhang, Chang Yin Gao, Bo Liao, Jian Sheng PanAbstract:solubility Abstract. In order to investigate the effects of probe geometric shape on cooling curves of Quenchants, the ISO Inconel 600 alloy probe and a flat probe (Dimension: 120 mm × 120 mm × 20mm, phase-transformation free CrNi-steel) were both adopted to measure the cooling curves of oil, water and aqueous polymer quenchant. By comparing and analyzing the cooling rate curves measured by the two kinds of probes, it can be found that the shape of water and oil’s cooling rate curves obtained using different probes are almost same. While those for the aqueous polymer quenchant are not, especially at the initial cooling phase. During the initial cooling phase the cooling rate measured by the flat probe fluctuates in a narrow range, whereas this phenomenon couldn’t be seen while using the ISO Inconel 600 alloy probe. The reason could be contributed to the geometric shape difference of the two kinds of probes and the property of inverse solubility of the aqueous polymer quenchant. In order to illustrate the inverse solubility property of the aqueous polymer Quenchants the probe geometric shape should be considered
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enhancing mechanical properties and avoiding cracks by simulation of quenching connecting rods
Materials Letters, 2007Co-Authors: Nailu Chen, Weimin ZhangAbstract:If the service load onto a part is heavy, e.g. for the connecting rods of high-power diesel engine, high mechanical properties are critically required. When quenched in oil, it cannot meet the requirements. While quenching it in aqueous polymer quenchant or water, the mechanical properties could be higher than that required but cracking would occasionally happen. In order to obtain the expected mechanical properties and avoid cracking by quenching and tempering, the heat transfer coefficients of Quenchants were measured and calculated, and the quenching process of connecting rods was simulated by using finite element method so that its processing parameters were determined. The results show that the mechanical properties of the treated rods have been enhanced and cracks were avoided.
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The Effects of Probe Geometric Shape on the Cooling Rate Curves Obtained from Different Quenchants
Solid State Phenomena, 2006Co-Authors: Nailu Chen, Weimin Zhang, Chang Yin Gao, Bo Liao, Jian Sheng PanAbstract:In order to investigate the effects of probe geometric shape on cooling curves of Quenchants, the ISO Inconel 600 alloy probe and a flat probe (Dimension: 120 mm × 120 mm × 20mm, phase-transformation free CrNi-steel) were both adopted to measure the cooling curves of oil, water and aqueous polymer quenchant. By comparing and analyzing the cooling rate curves measured by the two kinds of probes, it can be found that the shape of water and oil’s cooling rate curves obtained using different probes are almost same. While those for the aqueous polymer quenchant are not, especially at the initial cooling phase. During the initial cooling phase the cooling rate measured by the flat probe fluctuates in a narrow range, whereas this phenomenon couldn’t be seen while using the ISO Inconel 600 alloy probe. The reason could be contributed to the geometric shape difference of the two kinds of probes and the property of inverse solubility of the aqueous polymer quenchant. In order to illustrate the inverse solubility property of the aqueous polymer Quenchants the probe geometric shape should be considered.
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The effects of probe geometric shape on the cooling rate curves obtained from different Quenchants. Diffusion and defect data Solid state data Part B, Solid state phenomena 118:227–231
2006Co-Authors: Nailu Chen, Weimin Zhang, Chang Yin Gao, Bo Liao, Jian Sheng PanAbstract:solubility Abstract. In order to investigate the effects of probe geometric shape on cooling curves of Quenchants, the ISO Inconel 600 alloy probe and a flat probe (Dimension: 120 mm × 120 mm × 20mm, phase-transformation free CrNi-steel) were both adopted to measure the cooling curves of oil, water and aqueous polymer quenchant. By comparing and analyzing the cooling rate curves measured by the two kinds of probes, it can be found that the shape of water and oil’s cooling rate curves obtained using different probes are almost same. While those for the aqueous polymer quenchant are not, especially at the initial cooling phase. During the initial cooling phase the cooling rate measured by the flat probe fluctuates in a narrow range, whereas this phenomenon couldn’t be seen while using the ISO Inconel 600 alloy probe. The reason could be contributed to the geometric shape difference of the two kinds of probes and the property of inverse solubility of the aqueous polymer quenchant. In order to illustrate the inverse solubility property of the aqueous polymer Quenchants the probe geometric shape should be considered
Nailu Chen - One of the best experts on this subject based on the ideXlab platform.
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doi:10.4028/www.scientific.net/SSP.118.227 The Effects of Probe Geometric Shape on the Cooling Rate Curves Obtained from Different Quenchants
2014Co-Authors: Nailu Chen, Weimin Zhang, Chang Yin Gao, Bo Liao, Jian Sheng PanAbstract:solubility Abstract. In order to investigate the effects of probe geometric shape on cooling curves of Quenchants, the ISO Inconel 600 alloy probe and a flat probe (Dimension: 120 mm × 120 mm × 20mm, phase-transformation free CrNi-steel) were both adopted to measure the cooling curves of oil, water and aqueous polymer quenchant. By comparing and analyzing the cooling rate curves measured by the two kinds of probes, it can be found that the shape of water and oil’s cooling rate curves obtained using different probes are almost same. While those for the aqueous polymer quenchant are not, especially at the initial cooling phase. During the initial cooling phase the cooling rate measured by the flat probe fluctuates in a narrow range, whereas this phenomenon couldn’t be seen while using the ISO Inconel 600 alloy probe. The reason could be contributed to the geometric shape difference of the two kinds of probes and the property of inverse solubility of the aqueous polymer quenchant. In order to illustrate the inverse solubility property of the aqueous polymer Quenchants the probe geometric shape should be considered
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enhancing mechanical properties and avoiding cracks by simulation of quenching connecting rods
Materials Letters, 2007Co-Authors: Nailu Chen, Weimin ZhangAbstract:If the service load onto a part is heavy, e.g. for the connecting rods of high-power diesel engine, high mechanical properties are critically required. When quenched in oil, it cannot meet the requirements. While quenching it in aqueous polymer quenchant or water, the mechanical properties could be higher than that required but cracking would occasionally happen. In order to obtain the expected mechanical properties and avoid cracking by quenching and tempering, the heat transfer coefficients of Quenchants were measured and calculated, and the quenching process of connecting rods was simulated by using finite element method so that its processing parameters were determined. The results show that the mechanical properties of the treated rods have been enhanced and cracks were avoided.
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The Effects of Probe Geometric Shape on the Cooling Rate Curves Obtained from Different Quenchants
Solid State Phenomena, 2006Co-Authors: Nailu Chen, Weimin Zhang, Chang Yin Gao, Bo Liao, Jian Sheng PanAbstract:In order to investigate the effects of probe geometric shape on cooling curves of Quenchants, the ISO Inconel 600 alloy probe and a flat probe (Dimension: 120 mm × 120 mm × 20mm, phase-transformation free CrNi-steel) were both adopted to measure the cooling curves of oil, water and aqueous polymer quenchant. By comparing and analyzing the cooling rate curves measured by the two kinds of probes, it can be found that the shape of water and oil’s cooling rate curves obtained using different probes are almost same. While those for the aqueous polymer quenchant are not, especially at the initial cooling phase. During the initial cooling phase the cooling rate measured by the flat probe fluctuates in a narrow range, whereas this phenomenon couldn’t be seen while using the ISO Inconel 600 alloy probe. The reason could be contributed to the geometric shape difference of the two kinds of probes and the property of inverse solubility of the aqueous polymer quenchant. In order to illustrate the inverse solubility property of the aqueous polymer Quenchants the probe geometric shape should be considered.
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The effects of probe geometric shape on the cooling rate curves obtained from different Quenchants. Diffusion and defect data Solid state data Part B, Solid state phenomena 118:227–231
2006Co-Authors: Nailu Chen, Weimin Zhang, Chang Yin Gao, Bo Liao, Jian Sheng PanAbstract:solubility Abstract. In order to investigate the effects of probe geometric shape on cooling curves of Quenchants, the ISO Inconel 600 alloy probe and a flat probe (Dimension: 120 mm × 120 mm × 20mm, phase-transformation free CrNi-steel) were both adopted to measure the cooling curves of oil, water and aqueous polymer quenchant. By comparing and analyzing the cooling rate curves measured by the two kinds of probes, it can be found that the shape of water and oil’s cooling rate curves obtained using different probes are almost same. While those for the aqueous polymer quenchant are not, especially at the initial cooling phase. During the initial cooling phase the cooling rate measured by the flat probe fluctuates in a narrow range, whereas this phenomenon couldn’t be seen while using the ISO Inconel 600 alloy probe. The reason could be contributed to the geometric shape difference of the two kinds of probes and the property of inverse solubility of the aqueous polymer quenchant. In order to illustrate the inverse solubility property of the aqueous polymer Quenchants the probe geometric shape should be considered
Kyozo Arimoto - One of the best experts on this subject based on the ideXlab platform.
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A Brief Review on Test Systems Using a Ball Probe for Determination of Cooling Characteristics of Quenchants
Journal of Materials Engineering and Performance, 2020Co-Authors: Kyozo ArimotoAbstract:A wide variety of test systems have been developed to determine the cooling characteristics of Quenchants. Among them, rational systems with good reliability and cost performance have been adopted as domestic and international standards. This review mainly focuses on test systems using a small ball probe and discusses their development processes, features, and potential uses. Although a test system with a ball probe is not defined in current standards, it is known that specific ones used in the past contributed to enhancing the test. This literature survey found a classic test system with 7-mm-dia. silver or 4-mm-dia. chromium-nickel balls, which was created rationally for using the lumped heat capacity method, and was applied to a variety of Quenchants at the Kaiser Wilhelm Institute from 1928 to 1931. The institute finally increased the diameter of the silver ball probe to 20 mm due to manufacturing problems and applied it to various Quenchants, which was widely applied until the ISO 9950 standard using an Inconel cylindrical probe was established. In latter half of this report, prototypes of the test system using a small ball probe created by the author’s group since 2011 were briefly reviewed. This work solved the problem in the previous small ball probes with the current technology. The latest prototype uses a 4-mm-dia. platinum ball probe with a 0.25-mm-dia. sheathed thermocouple inserted into the center. The probe heated radiantly in a fixed state with halogen lumps is cooled in the quenchant in the container which is elevated by an electric linear actuator for robotics. This container movement creates a simple relative flow of quenchant around the probe, which has not been seen in the previous test systems. The use of the small ball probe has realized the compact and short-term test system.
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First Prototype of Rotary-Arm Type Test System Using a Small Ball Probe for Determination of Cooling Characteristics of Quenchants
Materials Performance and Characterization, 2014Co-Authors: Kyozo Arimoto, Fumiaki Ikuta, Hideo YokotaAbstract:Quenchants should be maintained based on their cooling characteristics, measured on a daily basis at every worksite for keeping their performance. A test system for this purpose is required to be compact, convenient, and reasonable. A rotary-arm type measurement apparatus using a small ball probe, which was reported by Tawara in 1941, is recognized as a compact one with an automatic device to specify a circular motion of the probe for its transfer from furnace to quenchant as well as a subsequent cooling process. In this study, the concept of Tawara’s method was assessed by producing its prototype based on current heating and rotation devices, and also measurement and control systems. Trends obtained from limited results of the prototype were consistent with those of Tawara. Reasonable repeatability in measured cooling characteristics of polymer solutions was verified by systematical tests. Relative flow that occurs steadily around the probe by its circular motion is a unique point of this apparatus to enhance its accuracy and repeatability. After reviewing test methods using rotary-arm and ball probes, and standards for cooling characteristics of Quenchants critically, contents, results, and outlooks on the prototype were described.
