Induction and Flame Hardening

2005 ◽  
pp. 249-255
Keyword(s):  
High Intensity ◽  
Surface Hardness ◽  
High Hardness ◽  
Case Depth ◽  
Dual Frequency ◽  
Gear Teeth ◽  
Preheat Treatment ◽  
Flame Hardening ◽  
Short Time

Abstract Induction and flame hardening are methods of hardening the surfaces of components, usually in selected areas, by the short-time application of high-intensity heating followed by quenching. These processes are used when gear teeth require high hardness, but size or configuration does not lend itself to carburizing and quenching the entire part. This chapter focuses on the processes involved in the induction and flame hardening, covering the applicable materials, hardening patterns, preheat treatment, quenching, tempering, surface hardness, case depth, hardening problems, dual-frequency process, and applications.

The Parameters Affecting Strength Calculation of Gears

2014 ◽  
Vol 635 ◽  
pp. 30-34
Author(s):  
Silvia Medvecká-Beňová ◽  
Peter Frankovský ◽  
Iveta Janeková
Keyword(s):  
Bending Strength ◽  
Surface Hardness ◽  
High Hardness ◽  
Metallurgical Industry ◽  
Strength Calculation ◽  
Gear Teeth ◽  
Transmission Mechanisms ◽  
Heat Treated ◽  
Heat Treated Steel ◽  
Treated Layer

Safety and traffic flow of production facilities also depends upon the reliability of technical security equipment. Gearing in the transmission mechanisms must satisfy the conditions of strength calculation. This calculation consists of checking of the gear teeth on bend and contact. From the stress of gears is show that the basic requirements of the material are high hardness of works surfaces and bending strength. Steels best meet these conditions. Used steel with surface hardness up to 350 HBW, or heat treated steel with hardness of 500-650 HBW. The advantage of these materials is the high value of the contact pressure in the tough centre core of the tooth. As a final heat treatment are used surface hardening, cementation and hardening, nitridation and carbo-nitridation. Good properties of heat-treated steels are at the correct thickness of the heat-treated layer of the tooth. This paper considers the appropriate choice of parameters to obtain the desired level of safety of gears in a gearbox to drive the conveyor in the metallurgical industry under increased load.

Increasing Hardness of Surface Layer of Low-Carbon Steel by Account of Plasma Treatment of Coating Modification

2021 ◽  
Vol 316 ◽  
pp. 794-802
Author(s):  
Andrey E. Balanovsky ◽  
Van Trieu Nguyen
Keyword(s):  
Surface Layer ◽  
Thermal Treatment ◽  
Plasma Treatment ◽  
Plasma Heating ◽  
High Surface ◽  
Surface Hardness ◽  
High Hardness ◽  
Diffusion Region ◽  
Low Carbon ◽  
Wide Range

The Purpose of paper is to conduct studies to assess the possibility of increasing the hardness of the surface layer of steel St3 grade by plasma heating of the applied surface coating containing powder alloy PR-N80X13S2R. Mixtures of pasta were divided into 2 groups: for furnace chemical-thermal treatment and plasma surface melting. The study of the microstructure showed a difference in the depth of the saturated layer, depending on the processing method, during chemical-thermal treatment-1 mm, plasma fusion - 2 mm. The results of measuring the surface micro-hardness showed that, the obtained coating from a mixture of PR-N80X13S2R + Cr2O3 + NH4Cl has a uniform high surface hardness (31-64 HRC), from a mixture of only PR-N80X13S2R - the surface hardness varies in a wide range (15-60 HRC). The study of the microhardness of the cross section of the surface layer showed that, the diffusion region: from a mixture of powder PR-N80X13S2R + Cr2O3 + NH4Cl has uniform hardness (450-490 HV); from a mixture of PR-N80X13S2R - hardness increases in the depth of the molten region (from 300 to 600 HV), and sharply decreases in the heat affected zone (210-170 HV). The use of PR-N80X13S2R alloy powder as the main component in the composition of the paste deposited on the St3 surface during plasma treatment leads to the formation of a doped surface layer with high hardness.

scholarly journals Prevalence of High-Intensity Drinking from Adolescence through Young Adulthood: National Data from 2016-2017

2019 ◽  
Vol 13 ◽  
pp. 117822181882297 ◽  
Author(s):  
Megan E Patrick ◽  
Yvonne M Terry-McElrath
Keyword(s):  
Binge Drinking ◽  
High Intensity ◽  
Memory Loss ◽  
Health Concern ◽  
Similar Data ◽  
12Th Grade ◽  
8Th Grade ◽  
Nationally Representative ◽  
The Individual ◽  
Short Time

High-intensity drinking (HID; ie, having 10+ drinks in a row) is a recognized public health concern due to the individual and public risks (eg, alcohol-related injuries, alcohol poisoning, memory loss, sexual risk) associated with consumption of a large quantity of alcohol over a relatively short time period. Using nationally representative samples of US 8th, 10th, and 12th grade students, and follow-up of subsamples of 12th graders, we present overall and sex-specific prevalence estimates of past 2-week HID from 29 966 individuals at the modal ages of 14 to 30 in 2016-2017. Similar data for the more commonly studied measure of binge drinking (having 5+ drinks in a row) is provided for comparison. HID prevalence ranged from 1% to 11.5% and was significantly higher for males than females at all ages other than modal age 14 (8th grade). Binge drinking prevalence ranged from 3.5% to 32.5%; males reported a higher prevalence than females at approximately half of the ages examined. Peak binge drinking and HID age for males was earlier (modal age 21/22) than that for females (modal age 21-24 for binge drinking and 25/26 for HID). The observed rapid increase in HID from adolescence through the early to mid-20s highlights the importance of prevention and intervention efforts targeted to these ages.

Short-time high-intensity exercise increases peripheral BDNF in a physical fitness-dependent way in healthy men

2019 ◽  
Vol 20 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Barbara Moura Antunes ◽  
Fabrício Eduardo Rossi ◽  
Ana Maria Teixeira ◽  
Fábio Santos Lira
Keyword(s):  
Physical Fitness ◽  
High Intensity ◽  
High Intensity Exercise ◽  
Healthy Men ◽  
Short Time

Research on Microstructures of Alloyed Layer by Plasma Surface Alloying with Tungsten and Molybdenum

2005 ◽  
Vol 297-300 ◽  
pp. 1108-1112
Author(s):  
Gao Yuan ◽  
Jin Yong Xu ◽  
Yan Ping Liu ◽  
Jian Zhong Wang ◽  
Xiaoyun Kui ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Composition ◽  
Surface Hardness ◽  
High Hardness ◽  
Carbon Steels ◽  
Alloying Elements ◽  
Low Carbon ◽  
Surface Alloying ◽  
Operating Life ◽  
Resistance To Wear

The alloying elements W-Mo cementation is carried out on the surfaces of low carbon steels by the technique of plasma metallurgy. Then by using the plasma-supersaturated carbonization, the composition of surface alloying layer reaches or approaches that of low-alloy HSS. In the end the surface alloying layer possesses high hardness, favorable red hardness and a significant improvement in properties after high temperature quenching and high temperature tempering. The surface cementation structure and phase structure of alloying layer were analyzed using metallographic microscope and X-ray diffraction (XRD), respectively; the distribution of surface composition and hardness of the layer were investigated by Glow Discharge Analytical Instrument (GDA) and micro hardness instrument, respectively; the resistance to wear was tested by a abrasion machine. The experimental results indicated that the layer consisted of W-Mo solid solution in Fe, the depth of the layer could reach 100µm and the content of tungsten exceeded 10% after ion W-Mo cementation. The carbon content of carburized layer was 1.3% above, which was composed of M6C carbide containing a lot of elements of W-Mo. The surface hardness of the alloying layer attained the HV1000 or so and appeared graded distribution after quenching and tempering. The application study showed that alloying elements W-Mo cementation was an appropriate technique to enhance surface resistance to wear and prolong operating life of accessories.

scholarly journals A Study Surface Layer and Hardness Produced by Induction Hardened S45C Steel

2014 ◽  
Vol 664 ◽  
pp. 43-47 ◽  
Author(s):  
Alain Kusmoko ◽  
Rosfian Arsyah Dahar ◽  
Hui Jun Li ◽  
Syamsul Hadi
Keyword(s):  
Surface Layer ◽  
Internal Stress ◽  
Induction Heating ◽  
Retained Austenite ◽  
Surface Hardness ◽  
Case Depth ◽  
Chemical Compositions ◽  
Different Temperatures ◽  
Significant Case ◽  
Cooling Speed

A cylinder of Carbon Steel S45C with a ferrite and pearlite structure was analysed to improve the hardness and surface layer as well as the toughness. Accordingly, it is important to undertake a heat treatment process for the hardness and surface layer of this steel. The heat teatment process was carried out using induction heating with five different temperatures of 800°C, 900°C, 1000°C, 1100°C and 1200 °C followed by water quenching with certain cooling speed. The chemical compositions and microstructures of these samples were characterized by spectrometer and optical microscopy. The microhardness of the samples was measured and the surface treatment of the samples was examined using an induction heating furnace. The results showed significant case depth and surface hardness as well as microstructure with martensite and retained austenite that is hard and brittle because of internal stress. Further, to reduce the amount of retained austenite and internal stress, it is necessary to carry out tempering of 300°C, 500°C and 700°C in order to produce toughness of the steel with slightly reduce in hardness.

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