Consistent and Repeatable Property and Residual Stress Control in Forged and Heat Treated Railway Wheels

2011 ◽  
Author(s):  
Jay Galbraith ◽  
George Ames ◽  
Scott Leister
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Pressure Control ◽  
Innovative Technology ◽  
Heat Treat ◽  
Heating And Cooling ◽  
Statistical Variation ◽  
Heat Treated ◽  
Railway Wheels ◽  
Process Controls

Consistent process control of wheel hardness and residual stresses developed during heat treatment are particularly important considerations for service life and safety of railway wheels. This paper details the process controls strategically located throughout an integrated, fully automated heat treatment system that can heat treat up to 65 railway wheels per hour. New, innovative technology such as in-line temperature measurements that control key process steps, uniform wheel heating and cooling, and quench water temperature and pressure control have resulted in wheel hardness and residual stress values with less statistical variation than older, traditional heat treat methods. Automatic serial number tracking and temperature measurement allow for statistical analysis of heat treat processes. Two years after the commissioning of this $18M facility, the quality and productivity benefits realized are discussed.

High Indentation Resistance of Aluminum Borate Based Glass-Ceramics

2013 ◽  
Vol 545 ◽  
pp. 3-7
Author(s):  
Pat Sooksaen ◽  
Pisud Prasertcharoensuk ◽  
Jiraporn Damnernsawat ◽  
Nimit Pattamawitayanimit
Keyword(s):  
Heat Treatment ◽  
Glass Melting ◽  
Isothermal Holding ◽  
Surface Hardness ◽  
Glass Ceramics ◽  
Isothermal Heat Treatment ◽  
Aluminum Borate ◽  
Holding Period ◽  
Heating And Cooling ◽  
Heat Treated

This study investigated the bulk crystallization of 54B2O3-19SiO2-17Al2O3-5BaO-5MgO (mol%) glass. Melting was carried out at 1500°C for 1 h using a bottom-load electric furnace. The glass melt was cast into a block and annealed at 500°C for 2 h. Isothermal heat treatment was carried out at 1100°C for 2, 4, 8, 16, 32 h to form bulk crystallized glass-ceramics using a heating and cooling rate of 5°C/min. Phases present in the glass-ceramic samples were studied by x-ray diffraction. Crystalline Al4B2O9 and Al18B4O33 were the main phases and the phase stability depended on the isothermal time. Microstructures were observed by a scanning electron microscope. The size of aluminum borate whiskers/rods tend to increase with longer isothermal holding period. The whisker/ rod-like crystals uniformly oriented throughout the microstructure in all heat treated samples. This led to interlocking microstructure and hence an increase in hardness and fracture toughness. Glass-ceramics synthesized at longer heat treatment times resulted in an increase in the surface hardness and shorter path length at the corner of the diamond pyramid-shaped indenter. Glass-ceramics synthesized in this study can be applied as high temperature resistant machinable materials because their microstructures can resist micro-cracking upon indentation.

Residual Stress Analysis Considering Phase Transformation and Transformation Plasticity for Heat-Treated Large Size Shaft

2016 ◽  
Vol 725 ◽  
pp. 647-652 ◽  
Author(s):  
Yusuke Yanagisawa ◽  
Yasuhiro Kishi ◽  
Katsuhiko Sasaki
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Phase Transformation ◽  
Air Cooling ◽  
Water Cooling ◽  
Stress Distributions ◽  
Transformation Plasticity ◽  
Large Size ◽  
Heat Treated ◽  
Good Agreement

The residual stress distributions of the forgings after both water-cooling and air-cooling were measured experimentally. The residual stress occurring during the heat-treatment was also simulated considering the phase transformation and the transformation plasticity. A comparison of the experiments with the simulations showed a good agreement. These results shows that the transformation plastic strain plays an important role in the heat treatment of large forged shafts.

Effect of Heat Treatment on the Reactivity and Crystallinity of Coal-Char

2005 ◽  
Author(s):  
Shouyu Zhang ◽  
Junfu Lu ◽  
Jianmin Zhang ◽  
Qing Liu ◽  
Guangxi Yue
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Treatment Time ◽  
Treatment Temperature ◽  
Coal Char ◽  
Heat Treatment Time ◽  
Heat Treat ◽  
Heat Treated ◽  
Layer Stacking ◽  
Crystalline Growth

The effect of heat treatment on the reactivity and crystallinity of char prepared from the vitrinite of two coals (YX, JJ) was investigated by using XRD and TGA in this paper. The results from TGA show that the reactivity of the chars from YXV and JJV decreases with the increase of heat treatment temperature. The reactivity of YXV char decreases quickly and significantly as heat treatment time increases. However, after heat treatment time of 60 min, it decreases slowly. The effect of heat treatment time on the reactivity of JJV char is small. The results from XRD show that the crystallinity of coal-char is determined by the intensity of heat treatment. When heat treatment time is more than 60 minutes, the turbostratic crystallite of YXV char prepared under 900°C changes remarkably and becomes more orderly. The aromatic layer stacking heights (Lc) of YXV Char when heat treated above 900°C increased with the increase of heat treatment time. The effect of heat treat time on Lc of JJV char is small, but under heat treatment temperature of 1200°C, the crystalline of JJV char grows distinctly. There is a good parallel relationship between the crystalline growth and deactivation of the chars. It can be concluded that the growth of the crystalline is the main reason for the deactivation of coal-char.

OPTIMIZATION of DYNAMIC CH4 GAS HEAT TREATMENT OF NANOCRYSTALLINE STRONTIUM HEXAFERRITE

2012 ◽  
Vol 05 ◽  
pp. 752-759 ◽  
Author(s):  
R. DEHGHAN ◽  
S. A. SEYYED EBRAHIMI ◽  
H. R. KOOHDAR
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Strontium Hexaferrite ◽  
Gas Flows ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Heating And Cooling ◽  
Heat Treated ◽  
Size And Morphology ◽  
Magnetic Nature

In this research the influence of dynamic CH 4 heat treatment on Sr -hexaferrite has been investigated. With the gas heat treatment, the phase composition, particles size and the morphology of Sr -hexaferrite change significantly. Due to this, the hard magnetic nature of the material changes from hard to soft. The strontium hexaferrite powder was prepared by conventional route with calcination of the mixture of strontium carbonate and hematite at 1100°C for 1 hour. Then the resultant Sr -hexaferrite was isothermally heat treated in methane dynamic atmosphere at various temperatures and gas flows for different times. The rate of heating and cooling were 10°C/min. The optimum conditions were obtained at 950°C and 15CC/min flow for 0.5 hour. The effects of gas heat treatment on the phase composition and the particles size and morphology were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibration Sample Magnetometery (VSM) techniques. The results show the decomposition of Sr -hexaferrite and reduction of the resultant hematite mainly to iron. The crystallite size of the resultant iron was also measured below 50nm.

The Effects of Residual Stress of Contact Fatigue Life for Railway Wheels

2005 ◽  
Vol 297-300 ◽  
pp. 115-121 ◽  
Author(s):  
Jung Won Seo ◽  
Byeong Choon Goo ◽  
Heung Chai Chung ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Fatigue Life ◽  
Contact Fatigue ◽  
Contact Load ◽  
Evaluation Procedure ◽  
Railway Wheel ◽  
Railway Vehicles ◽  
Contact Fatigue Life ◽  
Railway Wheels

Railway wheels and axles belong to the most critical components in railway vehicles. The service conditions of railway vehicles became more severe in recent years due to the increase of speed. Therefore, a more precise evaluation of railway wheel life and safety has been requested. Wheel/rail contact fatigue and thermal cracks due to braking are two major mechanisms of the railway wheel failure. One of the main sources of the contact zone failure is the residual stress. The residual stress on wheel is formed during the manufacturing process which includes a heat treatment, and then, is changed in the process of braking which results in wheel/rail contact stress and thermal stress. In this paper, an evaluation procedure for the contact fatigue life of railway wheel including residual stress is proposed. Also, the cyclic stress history for fatigue analysis is simulated by applying finite element analysis for the moving contact load. As a result, a fatigue life estimation methodology is proposed for railway wheels which includes the effects of residual stresses due to heat treatment, braking and repeated contact load, respectively.

Influence of Heat Treatment on Fatigue Strength of Drawn Steel Tubes for Small-Sized Single Pass Boiler

2011 ◽  
Vol 275 ◽  
pp. 109-112 ◽  
Author(s):  
Daisuke Yonekura ◽  
Yuta Fujie ◽  
Hayato Nishii ◽  
Hiroshi Yamakawa ◽  
Riichi Murakami
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Grain Size ◽  
Fatigue Strength ◽  
Steel Tube ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Post Heat Treatment ◽  
Single Pass ◽  
Heat Treated

Tension-tension fatigue tests were performed to examine the influence of post drawing heat treatment on the fatigue properties of drawn specific steel tube (STB340) for small-sized single pass boiler. The untreated, as-drawn and post drawing heat treated series were prepared for fatigue tests. The hardness, grain size and residual stress were measured for each series. As a result, the change of grain size and residual stress was small after post heat treatment. The drawn series was softened by post heat treatment but the hardness was still higher than untreated samples. The fatigue strength of the as-drawn and the post drawing heat treated series was higher than that of untreated series. In addition, the difference of endurance limit was small between as-drawn and post drawing heat treated series.

OPTIMIZATION OF Sr-HEXAFERRITE DYNAMIC GASEOUS HEAT TREATMENT BY CARBON MONOXIDE

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3133-3138
Author(s):  
A. YOURDKHANI ◽  
S. A. SEYYED EBRAHIMI ◽  
H. R. KOOHDAR
Keyword(s):  
Heat Treatment ◽  
Carbon Monoxide ◽  
Phase Composition ◽  
Strontium Hexaferrite ◽  
Gas Flows ◽  
Hard Magnetic Material ◽  
Heating And Cooling ◽  
Heat Treated ◽  
Size And Morphology ◽  
Magnetic Nature

In this research the influence of dynamic carbon monoxide heat treatment on Sr -hexaferrite has been investigated. Sr -hexaferrite is a hard magnetic material which under gaseous heat treatment, its phase composition and particles size and morphology change significantly. Due to these changings, the magnetic nature of the material changes from hard to soft. Strontium hexaferrite was prepared by conventional route with calcination of Sr -carbonat and hematite at 1100°C for 1 hour. Then Sr -hexaferrite was isothermally heat treated in carbon monoxide dynamic atmosphere at various temperatures and gas flows for different times. The rate of heating and cooling were 10°C/min. The optimum conditions was obtained at 850°C and 20cc/min flow for 0.5 hour. The effect of gaseous heat treatment on phase composition and particles size and morphology characterized by XRD and SEM. The results show the decomposition of Sr -hexaferrite and reduction of the resultant hematite mainly to iron. The crystallite size of the resultant powder was also measured below 50nm.

Effect of Heat Treatment on Formation of Al-Al3Ni Hypereutectic Alloys

2013 ◽  
Vol 592-593 ◽  
pp. 513-516
Author(s):  
Ladislav Čelko ◽  
Lenka Klakurková ◽  
Karel Slámečka ◽  
Bedřich Smetana ◽  
Tomasz Płociński ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Hvof Spraying ◽  
Heating And Cooling ◽  
Heat Treated ◽  
Initial Substrate ◽  
Constant Heating ◽  
Image Analysis Techniques ◽  
Intermetallic Layers

The paper deals with the mechanism of eutectic formation in a nickel coated aluminium system after heat treatment. The initial coating was produced from a nickel powder by means of high velocity oxyfuel (HVOF) spraying onto an aluminium sheet substrate. Specimens for investigations were manufactured immediately after the spraying. The specimens were heat-treated using a differential thermal analysis (DTA) apparatus up to the temperature of 700 or 900 °C and then cooled down to room temperature in argon atmosphere with a constant heating and cooling rate of 5 °C / min, under which Al-Al3Ni + Al3Ni hypereutectic alloys were formed within the initial substrate. Two different alloy microstructures consisting of intermetallic layers and coarse eutectic or an ultrafine well-dispersed eutectic were formed. Formation processes and resulting microstructures were studied by means of DTA, metallography, scanning electron microscopy, focused ion beam, energy dispersive microanalysis and image analysis techniques.

scholarly journals Residual Stress Measurement in Heat Treated Cylindrical Components

2021 ◽  
Author(s):  
M. Belassel ◽  
J. Pineault ◽  
M. Bolla ◽  
M. Brauss
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Microstructural Characterization ◽  
Plain Carbon Steel ◽  
X Ray Diffraction ◽  
Treatment Processes ◽  
Heat Treated ◽  
Xrd Techniques

Abstract Heat treatment processes can generate steep residual stress (RS) gradients and plastic deformation in metal components due to differential cooling and other effect such as phase transformation. The magnitude of residual stresses generated, and how quickly they vary spatially, will depend upon the material itself and the temperature gradients introduced during the heat treatment process. X-ray diffraction (XRD) techniques can be used to characterize residual stresses, as well as microstructural changes, including dislocation density and particle size in heat treated components. Plain carbon steel cylinders were heat treated, quenched and characterized using these methods. Residual stress measurements were performed via XRD using the Sin2Ψ technique and microstructural characterization was evaluated using the associated peak widths. Measurements were carried out both at the surface and through depth using electropolishing. The results indicate triaxial stress gradients exist in all samples investigated, with concomitant varying microstructural characteristics.

Residual Stress Analysis of A362 Aluminum Alloy Gear Case Using Neutron Diffraction

2018 ◽  
Vol 941 ◽  
pp. 1288-1294 ◽  
Author(s):  
Dimitry Sediako ◽  
Joshua Stroh ◽  
Alexandra McDougall ◽  
Ermia Aghaie
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Neutron Diffraction ◽  
Stress Analysis ◽  
Volume Fraction ◽  
High Stress ◽  
Microstructural Characterization ◽  
Heat Treated ◽  
Material State ◽  
Residual Stress Analysis

Mercury Marine has used a new alloy, Mercalloy A362, for the manufacturing of a re-designed lower unit transmission gearcase. The enhanced strength of the alloy allowed for a substantial weight reduction in the new design. The purpose of this study was to examine and determine why cracking may develop in the gear casing during in service testing. Two types of material states, (i) as cast and (ii) heat treated were compared. Metallography and neutron diffraction analysis was carried out at locations identified as being areas of high stress by Magma software – which was performed in a separate study. Microstructural characterization at these locations revealed microstructural and the compositional differences. Differences in the porosity, eutectic phase, and volume fraction of the precipitates were observed at various locations of interest in each material state. The residual stress analysis was performed with application of neutron diffraction and revealed that the stresses in the as-cast component reached a maximum value of 120 MPa, which is below the yield strength of the alloy. The heat treatment applied to the castings reduced the stress by approximately 50 MPa. Based on the microstructure and neutron diffraction results, it is likely that performing a heat treatment process extends the lifetime of the component, however, it may not completely eliminate the cracking problem. Farther studies are currently nearing completion, targeting the mass production of the redesigned gearcase.

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