Study on Development of a Surface Build-Up Welding Using CH-90 Electrode to Replace Mn-Containing Rail Steel

2006 ◽  
Vol 15-17 ◽  
pp. 989-994
Author(s):  
Bo Young Lee ◽  
Dae Hwan An ◽  
Jae Sung Kim ◽  
Hyung Kook Jin ◽  
Duck Hee Ryu
Keyword(s):  
Weld Metal ◽  
Work Hardening ◽  
Rail Steel ◽  
High Load ◽  
Chemical Compositions ◽  
Friction Coefficients ◽  
Steel Electrode ◽  
Load Carrying ◽  
Casting Steel ◽  
The Cost

Rail steel at crossing areas bears much higher loads over any other section of a regular railway. Mn-containing casting steel is normally used for its high load-carrying capability and reduced wear rate. However, since Mn-containing casting steel tends to have casting defects, the cost of manufacturing defect-free Mn-containing casting steel becomes quite expensive. Therefore, through the use of welding, this study investigates the possibility of resurfacing Mn-containing rail steel using a CH-90 electrode as an alternative to completely replacing it. In this study, a series of experimental build up weldings was made and their microstructures, chemical compositions, work-hardening index and friction coefficients were investigated. The results showed that both microstructures and chemical compositions from the build up weld section were similar to that of Mn-containing casting steel, showing an austenitic microstructure with approximately 13% Mn. The friction coefficients measured closely to one another as well (mu of Mn-containing steel = 0.847 and mu of the resurfaced weld metal = 0.831). The work-hardening index of the build up weld metal was 30% higher than that of Mn-containing casting steel. This difference could be attributed to the residual stresses in the build up weld metal which indicates that the hardening speed of the build up weld metal is faster than that of Mn-containing casting steel by impact. Therefore, build up welding, using a Mn-alloyed steel electrode on rail steel, could be a safe and economic alternative to the high cost of Mn-containing casting rail steel replacement.

scholarly journals Effect of additives introduction to fluxes manufactured from ladle electric steel slag

2019 ◽  
Vol 62 (8) ◽  
pp. 606-612
Author(s):  
N. A. Kozyrev ◽  
A. R. Mikhno ◽  
R. E. Kryukov ◽  
A. N. Kalinogorskii ◽  
L. P. Bashchenko
Keyword(s):  
Weld Metal ◽  
Rail Steel ◽  
Steel Slag ◽  
Aluminum Production ◽  
Chemical Compositions ◽  
Electric Steel ◽  
Total Oxygen ◽  
Waste Products ◽  
Ladle Slag ◽  
Welding Fluxes

Studies of welding and surfacing fluxes containing ladle slag of electric-steel production of rail steel of JSC “EVRAZ ZSMK” were carried out. Welding under the flux was performed on the samples of sheet steel 09G2S by Sv-08GА wire using the weldingtractor ASAW1250 at exhaust modes. Chemical compositions of welding fluxes and slag crusts were determined. Also chemical composition of the studied welded samples was determined according to GOST 10543 – 98 by x-ray fluorescence method on XRF-1800 spectrometer and by atomic emission method on DFS-71 spectrometer. Metallographic studies were carried out with the use of an optical microscope OLYMPUS GX-51. The content of total oxygen and surface oxygen was studied using the LECO TC–600 analyzer. The possibility of using technogenic waste products of metallurgical production is shown for the production of welding fluxes. The following components were used for production of welding flux: ladle slag of electric steelmaking of rail steel from “EVRAZ ZSMK” JSC; BSK barium-strontium modifier produced under the terms of 1717-001-75073896 – 2005 by “NPK Metallotekhnoprom”; slag of silicomanganese production from “West Siberian steel plant”; electrostatic dust of aluminum production from “RUSAL” (carbonfluor-containing supplement). The studies have shown the suitability of the use of ladle electric steel slag for welding and surfacing of alloyed metal. The introduction of various flux additives reduces the concentration of total oxygen in the weld metal, which in turn increases the toughness. From the point of oxygen concentration in weld metal and impact toughness, it is better to use silica-manganese slag and carbon-fluoride additive as flux additives.

Recent Patents on Abnormal Hydrodynamic Thrust Slider Bearings: Part II-the Second Mode of the Bearings

2020 ◽  
Vol 13 (1) ◽  
pp. 35-40
Author(s):  
Yongbin Zhang ◽  
Huansheng Cheng ◽  
Junyan Wang
Keyword(s):  
Operating Conditions ◽  
Moving Surface ◽  
Friction Coefficients ◽  
Surface Separation ◽  
Slider Bearings ◽  
Stationary Surface ◽  
Boundary Slippage ◽  
Load Carrying ◽  
Second Mode ◽  
Inlet Zone

Background: As a successive part, the paper introduces the second mode of abnormal hydrodynamic thrust slider bearings with divergent surface separations registered in the patents, where the boundary slippage is artificially designed both on the stationary surface in the inlet zone and on the whole moving surface. Objective : To introduce a second method for artificially designing the boundary slippage for the formation of abnormal hydrodynamic thrust slider bearings. Methods: The analytical results are presented for the introduced bearings. The performances of the bearings are demonstrated. Result: : In appropriate operating conditions, the introduced bearings can have considerable loadcarrying capacities with low friction coefficients on the scales 10-3 or 10-4. With the weakening of the boundary slippage on the moving surface, the load-carrying capacities of the bearings are all increased, while the friction coefficients of the bearings are all reduced. Conclusion: When the boundary slippage is present both on the stationary surface in the bearing inlet zone and on the whole moving surface, abnormal hydrodynamic thrust slider bearings can be designed with the surface separation in the bearing inlet zone lower than that in the bearing outlet zone. The performances of these bearings are quite satisfactory.

Ga-based liquid metal with good self-lubricity and high load-carrying capacity

2019 ◽  
Vol 129 ◽  
pp. 1-4 ◽  
Author(s):  
Jun Cheng ◽  
Yuan Yu ◽  
Jie Guo ◽  
Shuai Wang ◽  
Shengyu Zhu ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Carrying Capacity ◽  
High Load ◽  
Load Carrying Capacity ◽  
Load Carrying

A novel prosthetic finger design with high load-carrying capacity

2021 ◽  
Vol 156 ◽  
pp. 104121
Author(s):  
S. Liu ◽  
M. Van ◽  
Z. Chen ◽  
J. Angeles ◽  
C. Chen
Keyword(s):  
Carrying Capacity ◽  
High Load ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Prosthetic Finger

NDE Inspections and Simulation of Defects in Composite-Sintered Bushes

2013 ◽  
Vol 650 ◽  
pp. 582-587
Author(s):  
Kwang Hee Im ◽  
Ki Youl Kim ◽  
Ki Taek Shin ◽  
Han Hee Lee ◽  
To Kang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Carrying Capacity ◽  
Diffusion Bonding ◽  
Manufacturing Process ◽  
High Load ◽  
Load Carrying Capacity ◽  
Heavy Duty ◽  
Temperature Diffusion ◽  
Load Carrying

Bush is one of machine and automobile parts like brake used in drums and hubs in particular. Such bush parts are used for bearings of heavy-duty, large cars requiring wear resistance and high load carrying capacity. High temperature diffusion bonding has been applied for holding the both materials of the bushing together, which are outer steel materials and inner composite-sintered bushings. Therefore, it is very important evaluate the bonding integrity in manufacturing process. A simulation has been performed in order to evaluate the maximum defect sizes. Also, ultrasonic C-scan tests were performed for finding the defect in the composite-sintered bushings with the size of inherent flaws.

scholarly journals High load carrying structures made from folded composite materials

2020 ◽  
Vol 250 ◽  
pp. 112612
Author(s):  
Arthur Schlothauer ◽  
Urban Fasel ◽  
Dominic Keidel ◽  
Paolo Ermanni
Keyword(s):  
Composite Materials ◽  
High Load ◽  
Load Carrying

Low-Cost Lightweight Thin Film Solar Concentrators

2014 ◽  
Author(s):  
Gani B. Ganapathi ◽  
Art Palisoc ◽  
Bill Nesmith ◽  
Gyula Greschik ◽  
Koorosh Gidanian ◽  
...  
Keyword(s):  
Technology Development ◽  
Deep Structure ◽  
Low Cost ◽  
Development Program ◽  
Cost Benefit ◽  
Rigid Foam ◽  
Bird Droppings ◽  
Load Carrying ◽  
Pointing Accuracy ◽  
The Cost

A low-cost rigid foam-based concentrator technology development program was funded by the DOE SunShot Initiative to meet installed cost goals of $75/m2 vs. current costs of $200–250/m2. The cost reduction in this approach focuses primarily on designing a mirror module with a rigid foam center with stainless steel facesheets and reflective film. The low mechanical strength of the foam is compensated by optimizing the densities and dimensions to meet pointing accuracy requirements of 4 milliradians (mrad) in 27mph winds. Two alpha concentrators were built to validate the mirror module manufacturing process and one of them was accurate to 0.15 mrad RMS vs. the design requirement of 1 mrad RMS. To understand the lifetime reliability of the panels, fifteen 4-inch square samples were exposed to various environmental conditions including acid rain, bird droppings, thermal cycling, and the final results indicated no loss in reflectivity of 95%. UV testing will be performed in the next phase. Three mechanical structure options covering the range of large multi-faceted heliostats with diagonal load carrying elements, small single facet heliostats low to the ground and optimized truss-based deep structure designs were analyzed with FEA and analytically; results indicated a significant cost benefit (>2×) for the truss-based design over the other options. Other elements such as the controls, actuators were also considered in th analysis with vendor data. Cost trades were performed for heliostats ranging from 10m2 to 250m2. The results indicated a broad installed cost minimum around $113/m2 for heliostat sizes ranging from 80 m2 to 130 m2. Additional cost saving approaches will be considered in Phase 2 of the project.

Improving Toughness of Electron Beam Welds of Heavy Mn-Mo-Ni Steel Plates for Pressure Vessels

1993 ◽  
Vol 115 (3) ◽  
pp. 242-248 ◽  
Author(s):  
Y. Tomita ◽  
K. Tanabe ◽  
K. Koyama
Keyword(s):  
Electron Beam ◽  
Weld Metal ◽  
Steel Plate ◽  
Electron Beam Welding ◽  
Fracture Initiation ◽  
Pressure Vessels ◽  
Chemical Compositions ◽  
Intergranular Cracking ◽  
Electron Beam Weld ◽  
Upper Bainite

Electron beam welding melts and solidifies steel plate without using any welding material, unlike the conventional welding. Therefore, the toughness at the weld metal can decrease, depending on the chemical composition of the steel plate. Toughness at the electron beam weld can be increased by turning the microstructure from upper bainite into lower bainite and making the effective grain size finer. The microstructure can be controlled by the addition of alloy elements and optimization of impurity elements. In case the chemical compositions cannot be varied, largely because of the specification for their ranges, and the weld metal microstructure remains as upper bainite even after the application of microstructure control, methods to improve the toughness of electron beam weld itself, regardless of steel grades, becomes necessary. Phenomena peculiar to the electron beam weld are segregation during solidification and intergranular segregation over the dendrite surface. The fracture initiation is accelerated by the microcracks caused by the segregations during solidification. The fracture propagation is promoted by intergranular cracking caused by the intergranular segregation. By reducing these segregations, the fracture initiation and propagation are restrained and toughness increases despite the upper bainite microstructure. This can be achieved by the higher purification of steel. Through the foregoing investigations, ASTM A533 Type B Class 2 steel plate of 100 mm in thickness for electron beam welds has been developed for pressure vessels. Various welding tests as pressure vessels have been conducted, and it becomes clear that the developed steel plate has excellent toughness at the weld superior to those obtainable by conventional welding. The use of this steel greatly reduces the welding period compared to the conventional welding method.

Wind System Reliability and Capacity

2014 ◽  
Author(s):  
Alex Pavlak ◽  
Harry V. Winsor
Keyword(s):  
Power Systems ◽  
Carrying Capacity ◽  
System Reliability ◽  
Electric Power Systems ◽  
High Load ◽  
System Capacity ◽  
Wind Generation ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Superior Approach

Capacity measures a system’s ability to survive stress. For example, structures are engineered in part to have the capacity to survive the worst wind loads expected over the life of the structure. Likewise wind electric power systems should have the capacity to reliably survive the worst combination of high load and low wind. A superior approach for quantifying wind’s contribution to system capacity is well known. It is to view wind as a negative load and use the Effective Load Carrying Capacity (ELCC) methodology for a given year. A frequent mistake is to average these annual ELCC estimates. A main contribution of this paper is to explain why the system design criteria should take the worst of the annual ELCC estimates over a number of years and not an average of annual ELCC estimates. Based on extreme events, wind generation contributes little to system capacity (<6.6% of wind nameplate). The empirical evidence shows that wind generation is an energy source, not a capacity resource.

scholarly journals Increasing the load carrying capacity of highly loaded gears by nitriding

2019 ◽  
Vol 287 ◽  
pp. 02001 ◽  
Author(s):  
Johannes Koenig ◽  
Stefanie Hoja ◽  
Thomas Tobie ◽  
Franz Hoffmann ◽  
Karsten Stahl
Keyword(s):  
Carrying Capacity ◽  
High Sensitivity ◽  
Compound Layer ◽  
High Load ◽  
Load Carrying Capacity ◽  
Stable Compound ◽  
Current State ◽  
Load Carrying ◽  
State Of Research ◽  
Highly Loaded

Nitriding is a common heat treatment process for highly loaded gears. A very hard compound layer with a thickness of a few microns is produced at the surface of the gear. In the underlying material areas, a diffusion layer with nitride precipitations is formed. This publication summarizes the state of knowledge of nitrided gears and gives an overview of the current state of research in the field of nitrided gears. It can be concluded that a high load carrying capacity of nitrided gears is dependent on an adequate NHD and a stable compound layer. However, due to the increased surface roughness after nitriding, the risk of micropitting increases, too. Therefore, it may be favourable to grind the gears after nitriding. Ground gears also can provide a high load carrying capacity, but it must be taken into account that the wear performance will decrease significantly, since it is mainly influenced by the compound layer. In addition, nitrided gears usually show a high sensitivity against local load peaks. Beyond creating a stable compound the layer, the realization of a sufficient nitriding hardness depth with larger gear sizes is a focus in the current field of research.

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