Effect of induction heating rate on the quench hardness of cast iron with speroidal graphite

1980 ◽  
Vol 22 (4) ◽  
pp. 295-296
Author(s):  
V. A. Kolyada
Keyword(s):  
Cast Iron ◽  
Heating Rate ◽  
Induction Heating

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.

Kinetics of induction heating of cast iron in magnetic field

1976 ◽  
Vol 18 (10) ◽  
pp. 860-862
Author(s):  
P. I. Rusin ◽  
V. N. Pustovoit ◽  
Yu. M. Dombrovskii
Keyword(s):  
Magnetic Field ◽  
Cast Iron ◽  
Induction Heating ◽  
Kinetics Of

scholarly journals Fatigue Strength of Ferritic Ductile Cast Iron Hardened by Super Rapid Induction Heating and Quenching

2004 ◽  
Vol 45 (9) ◽  
pp. 2930-2935 ◽  
Author(s):  
Yoshitaka Misaka ◽  
Kazuhiro Kawasaki ◽  
Jun Komotori ◽  
Masao Shimizu
Keyword(s):  
Cast Iron ◽  
Fatigue Strength ◽  
Induction Heating ◽  
Ductile Cast Iron ◽  
Rapid Induction

scholarly journals Fatigue Strength of Ferritic Ductile Cast Iron Hardened by Super Rapid Induction Heating and Quenching

2005 ◽  
Vol 69 (12) ◽  
pp. 1057-1063 ◽  
Author(s):  
Yoshitaka Misaka ◽  
Kazuhiro Kawasaki ◽  
Jun Komotori ◽  
Masao Shimizu
Keyword(s):  
Cast Iron ◽  
Fatigue Strength ◽  
Induction Heating ◽  
Ductile Cast Iron ◽  
Rapid Induction

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.

scholarly journals Features of structure formation of surface layers with high content of boron on steel 15Х11МФ in the conditions of furnace and induction heating

2020 ◽  
pp. 26-30
Author(s):  
S.A. Knyazev
Keyword(s):  
Structure Formation ◽  
Heating Rate ◽  
Induction Heating ◽  
Treatment Time ◽  
Attractive Alternative ◽  
Surface Layers ◽  
High Alloy ◽  
Equilibrium Conditions ◽  
Furnace Heating ◽  
Non Equilibrium

The results of obtaining borated layers on 15H11MF high-alloy steel under equilibrium and non-equilibrium heating conditions are presented. Equilibrium conditions were achieved by slow furnace heating (with a heating rate of 0.1 oC/s), non-equilibrium – by induction heating (with a heating rate of 100 oC/s). The heating was controlled by measuring the thermoelectric power by a thermocouple welded to the surface of the sample by electric contact welding. The signal from the thermocouple was digitized by the ADC and transmitted to a computer where, at high speed, an array of data of temperature-time dependence of the process was formed. Furnace heating was carried out in a laboratory electric furnace at 1130 оС ± 5 оС, 1150 оС ± 5 оС and 1160 оС ± 5 оС. Induction heating was carried out to temperatures of 1180 oC ± 20oC, 1200 oC  ± 20oC, 1220 oC ± 20oC. The possibility of significant reduction of the treatment process from 3 hours to 2 minutes due to the intensifying action in non-equilibrium conditions of structure formation is shown. Boron saturation came from the paste. Saturating paste consisted of 60% boron carbide, 30% NaF, 10% CaF2. The method of metallographic research shows not only the morphological differences of the obtained surface layers, but also established the predominant mechanism of boron diffusion into high-alloy martensitic steel. During furnace heating (1150оС), a solid boron with a thickness of up to 50 μm and a hardness of 15100 MPa is formed. At a depth of up to 150 μm, grain boundary diffusion is noticeable, which obviously dominates in the processes of boron saturation of high-alloy steels. At temperatures of 1160 oC and furnace heating under a solid layer of boride with a thickness of 110 μm, a two-phase zone is formed, which consists of boride and a solid solution with a thickness of 70 μm. This layer is more defective. Induction heating with boron saturation forms a thick (up to 200 μm) layer of coarse boride crystallites (18900 – 9270 MPa) with an eutectic structure (6440 MPa), which becomes coarser with increasing temperature from 1180 to 1220 оС. The ability to obtain solid hardened layers in a short treatment time makes boron saturation from pastes a more attractive alternative among other chemical-heat treatment technologies.

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