Coupled Effects of Heating Method and Rate on the Measured Nonisothermal Austenization Temperature of Steel SUS420J1 in Heat Treatment

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Hongze Wang ◽  
Yosuke Kawahito ◽  
Yuya Nakashima ◽  
Kunio Shiokawa
Keyword(s):  
Heat Treatment ◽  
Temperature Distribution ◽  
Heating Rate ◽  
Induction Heating ◽  
Laser Heating ◽  
Treatment Method ◽  
Infrared Heating ◽  
Heating Rates ◽  
Element Analysis ◽  
Heating Method

Steel SUS420J1, which is the key material of turbine blade, is generally treated by heat to improve the strength prior to use. And the austenization process at different heating rates would determine the depth and width of heat treatment. In this paper, the austenization temperatures in heat treatment with the heat from induction wire, infrared lamp, and laser are measured, respectively. The effect of heating rate on the austenization temperature has been investigated. The research results show that the measured austenization temperature increases with the heating rate. And this trend is specially enlarged in the heat treatment method with larger gradient of temperature distribution, e.g., laser. The calculated phase transformation threshold shows that negative linear relationship exists between the logarithmic heating rate and the logarithmic austenization threshold for both induction heating and infrared heating, while abnormal relationship exists for laser heating. Thermal finite element analysis (FEA) models are then developed to calculate the temperature distributions in these three heating methods, and the calculated results show that the nonuniform temperature distribution leads to the gap between the measured austenization temperature and that of the material, which also leads to the abnormal variation law of austenization threshold in laser heating. The measured austenization temperature in induction heating method is thought to be the closest to the actual austenization temperature of the material among these three methods. This paper provides a guide for choosing the proper parameters to heat the steel SUS420J1 in hardening.

Design of an induction heating coil coupled with magnetic flux concentrators for barrel heating of an injection molding machine

2014 ◽  
Vol 229 (3) ◽  
pp. 518-527 ◽  
Author(s):  
Huy-Tien Bui ◽  
Sheng-Jye Hwang
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Magnetic Flux ◽  
Heating Rate ◽  
Induction Heating ◽  
Heating Time ◽  
Resistance Heating ◽  
Molding Machine ◽  
Heating Method ◽  
Heating Coil

In an injection molding machine, the conventional barrel heating system which uses resistance heating method (RH) has some drawbacks such as low heating rate, long heating time, and energy loss. With induction heating (IH) technique, the barrel can better handle almost all of these disadvantages. However, non-uniform temperature distribution on inside surface of a barrel is the main drawback of induction heaters. A working coil coupled with magnetic flux concentrators via adjustment of magnetic flux concentrator spacing to achieve uniformity of magnetic flux and temperature distribution on the inside surface of a barrel was proposed and experimented. Results showed that, when barrel was heated by induction heating method with the proposed induction heating coil, heating time to reach a specific temperature could be reduced, and heating rate increased compared to resistance heating method. With 8 mm pitch of magnetic flux concentrators on a coil, the temperature distribution was the most uniform.

An Experimental Study of Microscopic Explosive Boiling Induced by Pulsed-Laser Irradiation

2002 ◽  
Author(s):  
Xiulan Huai ◽  
Zhaoyi Dong ◽  
Dengying Liu ◽  
G.-X. Wang
Keyword(s):  
Experimental Study ◽  
Heating Rate ◽  
Laser Heating ◽  
High Speed ◽  
Quartz Substrate ◽  
Pulsed Laser ◽  
Bubble Nucleation ◽  
Nucleation Temperature ◽  
Heating Rates ◽  
Explosive Boiling

Microscopic explosive boiling due to rapid heating has found many applications in modern technologies such as thermal ink jet printing, laser cleaning, and laser surgery. It is a nonequilibrium process involving an extremely high liquid superheating. This paper presents an experimental study of such an explosive vaporization process induced by firing a microsecond pulsed laser beam on a thin Pt film deposited on a quartz substrate. The temperature variation of the Pt film is measured by recording the electric resistance of the film during laser heating and subsequent cooling. A high-speed photographic technique is employed to visualize the bubble formation and the explosive evaporation process. Explosive boiling experiments have been carried out in either a pool of acetone liquid or a thin acetone film covering the Pt film. The heating rate achieved ranges from 8.0×106 K/s to 9.0×107 K/s. Violent explosive boiling was observed in the case of a liquid film and the vapor bubbles together with liquid droplets were expelled from the Pt film. While in the case of a liquid pool, only a large cluster of bubbles was formed on the Pt film during laser heating. A close examination of the temperature curves reveals a sudden reduction in the heating rate during laser heating, and an apparent bubble nucleation temperature can be defined. Experimental data show that this apparent bubble nucleation temperature is a strong function of the heating rate. It is close to the equilibrium boiling point at low heating rates while approaches the homogeneous nucleation temperature at high heating rates.

Influence of Specimen Design on Maximum Heating Rate and Temperature Variation During Induction Heating in an 805L Dilatometer

2021 ◽  
Author(s):  
Robert Cryderman ◽  
Finn Bamrud ◽  
Tareq Eddir ◽  
Robert Goldstein
Keyword(s):  
Heating Rate ◽  
Induction Heating ◽  
Induction Hardening ◽  
Test Sample ◽  
Carbon Steels ◽  
Transient Temperature ◽  
Thin Wall ◽  
Heating Rates ◽  
Temperature Variations ◽  
Metallurgical Analysis

Abstract Commercially, carbon steels are induction heated at heating rates on the order of 100 to 1,000 °C·s-1 for surface hardening. The high precision DIL 805L dilatometer employs induction heating and is often used to study transformation characteristics and prepare test specimens for metallurgical analysis. However, heating the commonly used 4 mm diameter by 10 mm long specimens at rates above 50 °C·s-1 results in non-linear heating rates during transformation to austenite and large transient temperature variations along the specimen length. These limitations in heating rate and variances from ideal uniform heating can lead to inaccurate characterization of the transformation behavior compared to commercial induction hardening practices. In this study it is shown that changing the specimen design to a thin wall tube allows faster heating rates up to 600 °C·s-1 and modifies the pattern of temperature variations within the test sample. The response of selected specimen geometries to induction heating in the dilatometer is characterized by modelling and tests using multiple thermocouples are used to verify the models. It is demonstrated that the use of properly designed tubular test specimens can aid in more accurately establishing transformation characteristics during commercial induction hardening.

scholarly journals Effect of Heating Rate on Accelerated Carbide Spheroidisation (ASR) in 100CrMnSi6-4 Bearing Steel

2014 ◽  
Vol 59 (3) ◽  
pp. 1199-1203 ◽  
Author(s):  
D. Hauserova ◽  
J. Dlouhy ◽  
Z. Novy
Keyword(s):  
Thermal Cycling ◽  
Heating Rate ◽  
Induction Heating ◽  
Transformation Temperature ◽  
Bearing Steel ◽  
Heating Rates ◽  
Annealing Stage ◽  
Ferritic Matrix ◽  
Bearing Steels

Abstract Typical processing routes for bearing steels include a soft annealing stage, the purpose of which is to obtain a microstructure containing globular carbides in ferritic matrix. A newly developed process called ASR cuts the carbide spheroidisation times several fold, producing considerably finer globular carbides than conventional soft annealing. The present paper explores the effect of the heating rate and temperature on the accelerated carbide spheroidisation process and on the resulting hardness. Accelerated spheroidisation was achieved by thermal cycling for several minutes around various temperatures close to the transformation temperature at various heating rates applied by induction heating.

Determination of Temperature Limits for Heat Exchanger Joint Assembled of Solid Stainless Tubesheet With Girth Flanges

2017 ◽  
Author(s):  
Bassel Y. Mohamed ◽  
Mohamed A. Hamdy ◽  
Tamer I. Eid
Keyword(s):  
Heat Exchanger ◽  
Temperature Distribution ◽  
Heat Exchangers ◽  
Transient Analysis ◽  
Transient Temperature ◽  
Heating Rates ◽  
Element Analysis ◽  
Transient Temperature Distribution ◽  
Steel Heat

Although heat exchangers are built according to international codes and proved to be leak tight by hydrotesting at ambient temperature, leak of stainless steel heat exchangers girth flanges at the tubesheet gaskets likely occurs during startup and operation at high temperatures. Accordingly, evaluation of the design to assure leak free operation considering anticipated thermal events is required. WRC 510 bulletin [4] introduces a simplified analytical method to address this issue and provides safe guarding against leakage. This study is performed on solid 300 series stainless stationary tubesheet flanged with girth flanges having the same or different material of construction. A thermal finite element analysis is performed to obtain the transient temperature distribution through a girth flanges and stationary tubesheet assembly of a heat exchanger using SOLIDWORKS® SIMULATION [7]. The model of the flanged joint consists of two girth flanges with a tubesheet and gaskets in between. Thermal time dependent transient analysis of the above model is conducted to compute the temperature distribution in the flanged joint assembly for different time steps. Further, these temperature distributions are used to compute the expansion, deflection and rotation for the flanged joint parts using WRC 510 bulletin [4] equations. The study determines both the permissible heating rates during startup and the temperature limits, for the example studied, which are suitable for using solid 300 series stainless tubesheet for both material types of the girth flanges to have the most leak tight & economical assembly when the minimum design metal temperature allows these materials.

Estimate the Melt Flow Length with Internal Induction Heating for the Injection Molding Process

2020 ◽  
Vol 863 ◽  
pp. 97-102
Author(s):  
Huynh Duc Thuan ◽  
Tran Anh Son ◽  
Pham Son Minh
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Heating Rate ◽  
Induction Heating ◽  
Heating System ◽  
Mold Temperature ◽  
Heating Process ◽  
Injection Molding Process ◽  
Molding Process ◽  
Internal Induction

In this paper, an induction heating system was applied to the heating stage in the injection molding process. Through simulation and experiment, the heating process was estimated by the temperature distribution and the heating rate. In the simulation, the mold temperature was increased from 30°C to 180°C in 9 s. Therefore, the heating rate was higher than 16°C/s, which represents a positive result in the field of mold heating. Additionally, the temperature distribution revealed that the higher temperature is concentrated on the gate area, while the outside of the mold cavity is at a lower temperature. The same parameters were applied to both the experiment and the simulation, and the results were in good agreement.

Investigation of Heat Treatment of Gears Using a Simultaneous Dual Frequency Induction Heating Method

2015 ◽  
Vol 51 (11) ◽  
pp. 1-4
Author(s):  
Dongwon Yun ◽  
Heechang Park ◽  
Jeong-Hoi Koo ◽  
Sangyong Ham ◽  
Sunghwi Lee
Keyword(s):  
Heat Treatment ◽  
Induction Heating ◽  
Dual Frequency ◽  
Heating Method

Observation of Furnace-Induction Quenched Microstructure in High Carbon High Chromium Steel

2017 ◽  
Vol 904 ◽  
pp. 36-39 ◽  
Author(s):  
Koshiro Mizobe ◽  
Kohei Egawa ◽  
Katsuyuki Kida
Keyword(s):  
Heat Treatment ◽  
Induction Heating ◽  
Mass Production ◽  
Treatment Method ◽  
Chromium Steel ◽  
The Other ◽  
Material Structure ◽  
High Carbon ◽  
High Chromium ◽  
Heat Treatment Method

There are two major heating methods used in industrial situations. One is furnace heating which is popular for mass production as it hardens the steel uniformly. The other is induction heating which is energy saving but hardens the steel unevenly. We developed a combined heat treatment method, furnace-induction heating (FIH), and observed the material structure using picral and nital etching.

Sign in / Sign up

Export Citation Format

Share Document