Thermal Behaviour of Steel Plate during Accelerated Cooling

2010 ◽  
Vol 638-642 ◽  
pp. 2706-2711
Author(s):  
J.M. Pyykkönen ◽  
David C. Martin ◽  
Mahesh C. Somani ◽  
P.T. Mäntylä
Keyword(s):  
Heat Transfer ◽  
Phase Transformation ◽  
Physical Properties ◽  
Microstructure Evolution ◽  
Steel Plate ◽  
High Rate ◽  
Critical Parameters ◽  
Accelerated Cooling ◽  
Air Cooling ◽  
Thermal Physical Properties

Recent trends in the production of high strength steel plate call for increasingly sophisticated thermo-mechanical treatment schedules, including the use of high rate accelerated cooling after finish rolling in order to achieve the desired microstructure and mechanical properties. Achieving the necessary cooling process control accuracy in such cases requires a sound understanding and description of the interactions between external heat transfer processes and changes in internal energy due to phenomena such as solid-state phase transformations. The thermal physical properties of the evolving microstructures of complex phase and martensitic steels vary greatly, and are strongly dependent on temperature and constituent phases. As a result, critical parameters such as thermal diffusivity cannot be accurately estimated without appropriate linkage to both phase transformation kinetics and temperature. In the present study, a numerical simulation has been developed to investigate the unsteady heat transfer and phase transformation behaviour of a moving steel plate during accelerated cooling. The simulation includes semi-empirical microstructure evolution sub-models, fitted to measured CCT data using non-linear regression. These are coupled to thermal-physical properties sub-models and thermal conduction calculations. A comprehensive suite of thermal boundary condition models which account for direct water cooling, forced convection film boiling, air cooling, radiation and heat transfer between plate and transport rollers are also included. The required equations for the plate temperature and microstructure evolution are solved numerically using a cell centred finite volume method, and the model has been validated by comparing simulated cooling stop temperatures with measurements obtained on the plate cooling section of an industrial plate mill. The predicted cooling stop temperatures of steel plates for different thicknesses, velocities and water flow rates are in good agreement with plant operational data.

Simulation of Cooling Process of Medium Thickness Steel Plate

2008 ◽  
Vol 594 ◽  
pp. 34-38
Author(s):  
Ji Guang Han ◽  
Yang Bai
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Steel Plate ◽  
Accelerated Cooling ◽  
Mathematics Model ◽  
Cooling Process ◽  
Medium Thickness

By carefully researching and analyzing on cooling process of medium thickness steel plate, a mathematics model of heat transfer and its corresponding simulation model are established and evaluated with finite discrimination for a selected cooling object, and a simulation model is established. Through simulation and locate testing, the calculated values obtained are agreed very well with the measured ones. This indicates that the simulation model can preferably reveal the accelerated cooling process of medium thickness steel plate and can be applied to guide the manufacture of medium thickness steel plate.

A Method for Simulation of Microstructure Evolution in 980MPa-ULCB Steels during On-Line Heating Treatment

2011 ◽  
Vol 214 ◽  
pp. 472-476
Author(s):  
Jian Xin Zhang ◽  
Ai Hua Gao
Keyword(s):  
Microstructure Evolution ◽  
Treatment Process ◽  
Steel Plate ◽  
Volume Fraction ◽  
High Strength ◽  
Accelerated Cooling ◽  
Line Heating ◽  
Treatment Parameter ◽  
Heating Treatment ◽  
On Line

Influence of the off line heating treatment parameter on the microstructure of a high strength steel plate was studied system previously. However, the information about the effect of on-line heating treatment process on ultra-high steel plate, especially on the plate with a tensile strength 980MPa or above, is limited due to the lack of effective method to simulation for the on-line heating treatment process. A method, which is preformed with a thermo-mechanical simulator, simulation the parameter of on-line heating treatment on the microstructure evolution a high strength ULCB steel plate after the accelerated cooling. By means of observation the original microstructure and microstructure morphologies varied with the parameter of the on-line heating treatment process, the present results demonstrate the microstructure characterizations before and after heating treatment process, while also the distribution of M(C, N) particles on lath boundaries or lath interior and the volume fraction and the average size of M/A island.

Effect of Moisture Content on Thermal Physical Properties and Heat Transfer of Plywood during Hot-Pressing

2013 ◽  
Vol 652-654 ◽  
pp. 1283-1289
Author(s):  
Xiang Liu ◽  
Sun Guo Wang ◽  
Wen Ding Li ◽  
Lei Chen
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Moisture Content ◽  
Physical Properties ◽  
Specific Heat ◽  
Heating Rate ◽  
Hot Pressing ◽  
Slow Heating ◽  
Effect Of Moisture ◽  
Thermal Physical Properties

In order to investigate the effect of moisture content on thermal physical properties and heat transfer of plywood during hot pressing, the quasi steady method was applied to measure the thermal conductivity, specific heat and thermal diffusivity values of the resinated plywood assembly with a UF loading rate of 300g/m2 under different moisture conditions. Results showed that with the increase of moisture content in a range of 10-22%, the thermal conductivity and specific heat of the plywood assembly enhanced significantly, and that plywood hot pressing noticeably consisted of fast heating and slow heating phases: during the first phase the heating rate of the core ply was quickened with the increase of moisture content while the second phase did not show any significant impact of moisture content on the corresponding heating rate.

Coupled Temperature-Microstructure Model for Predicting Temperature Distribution and Phase Transformation in Steel for Arbitrary Cooling Curves

2020 ◽  
Vol 13 (3) ◽  
Author(s):  
Sandip K. Saha ◽  
Akhilesh Kumar
Keyword(s):  
Heat Transfer ◽  
Phase Transformation ◽  
Steel Plate ◽  
Plate Thickness ◽  
High Strength Steels ◽  
High Strength ◽  
Rolling Speed ◽  
Transfer Model ◽  
Advanced High Strength Steels ◽  
Quenching Time

Abstract This study aims at developing a numerical model that can be employed for simulating the thermomechanical treatment to develop the advanced high strength steels. The developed numerical method is used to calculate the heat transfer coefficient of the quenching medium during the continuous cooling of the steel using the inverse heat transfer model for predefined cooling paths. Further, the phase transformation models are used to predict the final microstructure of the steel plate. The cooling rate, plate thickness, and rolling speed are varied to evaluate the temperature and microstructure distribution in the steel plate. It is found that on increasing the quenching time, the transformation fraction from austenite to ferrite and bainite phases increases and the corresponding martensite fraction decreases. The temperature variation in the plate is significant due to the change in plate thickness and rolling speed for a given quenching time. The present model will be useful for designing process parameters to obtain desired microstructures in third-generation advanced high strength steels.

scholarly journals A Study of Rotor Cavities and Heat Transfer in a Cooling Process in a Gas Tubine

1992 ◽  
Author(s):  
R. S. Amano ◽  
V. Pavelic
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Flow ◽  
Numerical Study ◽  
Heat Transfer Process ◽  
High Rate ◽  
Turbulent Heat Transfer ◽  
Air Cooling ◽  
Turbulent Heat ◽  
Accurate Analysis

A high temperature flow through a gas-turbine produces a high rate of turbulent heat transfer between the fluid flow field and the turbine components. The heat transfer process through rotor disks causes thermal stress due to the thermal gradient as well as the centrifugal force causes mechanical stresses; thus an accurate analysis for the evaluation of thermal behavior is needed. This paper presents a numerical study of thermal flow analysis in a two-stage turbine in order to better understand the detailed flow and heat transfer mechanisms through the cavity and the rotating rotor-disks. The numerical computations were performed to predict thermal fields throughout the rotating disks. The method used in this paper is the ‘segregation’ method which requires a much smaller number of grids than actually employed in the computations. The results are presented for temperature distributions through the disk and the velocity fields which illustrate the interaction between the cooling air flow and gas flow created by the disk rotation. The temperature distribution in the disks shows a reasonable trend. The numerical method developed in this study shows that it can be easily adapted for similar computations for air cooling flow patterns through any rotating blade disks in a gas turbine.

A Study of Rotor Cavities and Heat Transfer in a Cooling Process in a Gas Turbine

1994 ◽  
Vol 116 (2) ◽  
pp. 333-338 ◽  
Author(s):  
R. S. Amano ◽  
K. D. Wang ◽  
V. Pavelic
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Flow ◽  
Numerical Study ◽  
Heat Transfer Process ◽  
High Rate ◽  
Turbulent Heat Transfer ◽  
Air Cooling ◽  
Turbulent Heat ◽  
Accurate Analysis

A high-temperature flow through a gas turbine produces a high rate of turbulent heat transfer between the fluid flow field and the turbine components. The heat transfer process through rotor disks causes thermal stress due to the thermal gradient just as the centrifugal force causes mechanical stresses; thus an accurate analysis for the evaluation of thermal behavior is needed. This paper presents a numerical study of thermal flow analysis in a two-stage turbine in order to understand better the detailed flow and heat transfer mechanisms through the cavity and the rotating rotor-disks. The numerical computations were performed to predict thermal fields throughout the rotating disks. The method used in this paper is the “segregation” method, which requires a much smaller number of grids than actually employed in the computations. The results are presented for temperature distributions through the disk and the velocity fields, which illustrate the interaction between the cooling air flow and gas flow created by the disk rotation. The temperature distribution in the disks shows a reasonable trend. The numerical method developed in this study shows that it can be easily adapted for similar computations for air cooling flow patterns through any rotating blade disks in a gas turbine.

scholarly journals Phase Transformation Behavior of a β-Solidifying γ-TiAl-Based Alloy from Different Phase Regions with Various Cooling Methods

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 731 ◽  
Author(s):  
Xiaobing Li ◽  
Hao Xu ◽  
Weiwei Xing ◽  
Bo Chen ◽  
Yingche Ma ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Single Phase ◽  
High Rate ◽  
Air Cooling ◽  
Transformation Behavior ◽  
Phase Transformation Behavior ◽  
Backscattered Electrons ◽  
Electron Probe Micro Analyzer ◽  
Α2 Phase ◽  
Cooling Methods

The phase transformation behavior of Ti-42Al-5Mn (at.%) alloy from different phase regions with various cooling rates was investigated based on electron probe micro analyzer-backscattered electrons (EPMA-BSE). It is shown that β→α2′ takes place when this alloy is cooled at a high rate, such as water quenching (WQ), oil cooling (OC), from β single phase. With the decreasing cooling rate to air cooling (AC), β→α2′ is restrained and β→γ is promoted by forming γ platelets. The room-temperature microstructure is βo + α2 when alloy cooled (WQ and OC) from (β + α) dual-phase. However, under AC, β→γ occurs and γ platelets form. It should be noted that α2→γ happens when this alloy cooled from 1180 °C (>Teut) by OC and AC, forming an incomplete lamellae (α2/γ) structure in the α2 phase. However, when the alloy cooled from 1100 °C (<Teut), α2/γ→βo,sec occurs and complete lamellae generates in α2 phase.

The Experimental Study of Phase Transformation Heat─Transfer in Simulation of Grinding of Ti Alloy

2007 ◽  
Vol 359-360 ◽  
pp. 548-553
Author(s):  
Jia Long Ren ◽  
Wei Li ◽  
Hua Hang ◽  
Xiao Yan Guan
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Phase Transformation ◽  
Test Sample ◽  
Air Cooling ◽  
Ti Alloy ◽  
Apparent Mass ◽  
Jet Cooling ◽  
Forced Air ◽  
Positive Effect

Enhancing the cooling to spread heat in the process of the material cutting and milling has positive effect on increasing the efficiency of cutting and milling and assuring the apparent mass of test sample cut and milled. Basing on the experiment about the mixture of fixed pressure, fixed air and different quantity of water atomizing jet cooling the Ti alloy, this article discusses performance and regulation of phase transformation heat—transfer of simulating grinding Ti alloy forced air cooling by the mixture of fixed pressure, fixed air and little water.

ALCOA QC-10

Alloy Digest ◽  
2009 ◽  
Vol 58 (7) ◽  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Aluminum Alloys ◽  
Physical Properties ◽  
Tensile Properties ◽  
Mold Material ◽  
Cast Products

Abstract Aluminum has long been accepted as a mold material. This alloy has a combination of faster machining, highest heat transfer, lighter weight, higher strength in thick sections, and greater thermal conductivity than other aluminum alloys. This datasheet provides information on physical properties, hardness, elasticity, and tensile properties. It also includes information on forming and machining. Filing Code: AL-423. Producer or source: Alcoa Forged and Cast Products.

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