Influence of the State of the Contact Surfaces on the Formation of the Joint of Steel and Brass during Cold Cladding

2018 ◽  
Vol 284 ◽  
pp. 319-325 ◽  
Author(s):  
A.V. Shaparev ◽  
I.A. Savin
Keyword(s):  
Plastic Deformation ◽  
Surface Hardening ◽  
The State ◽  
Diffusion Annealing ◽  
Contact Surfaces

Joint plastic deformation of the components of bimetal 1 according to OST 3-6648-91 brass L90-steel 18JUA-brass L90 should be produced with the greatest possible compression to obtain the necessary strength of the joining of the layers, ensuring the strip looking into a roll without stratification. Preparation of contact surfaces before cold cladding is one of the most important technological operations. The influence of such factors on the strength of the bonding of bimetal layers as the surface hardening of contact surfaces, the microgeometry of contact surfaces, the temperature of diffusion annealing after cladding, the influence of the ratio of the thicknesses of bimetal layers was investigated. Technological recommendations for the production of bimetal 1 on OST 3-6648-91 brass L90-steel 18JUA-brass L90 by the method of cold cladding are developed.

Contact Surfaces Preparation in Manufacturing of Bimetallic Strips CuZn10 Brass - C22E Steel - CuZn10 Brass

2021 ◽  
Vol 410 ◽  
pp. 463-468
Author(s):  
Alexander V. Shaparev
Keyword(s):  
Bond Strength ◽  
Surface Hardening ◽  
Heating Temperature ◽  
Diffusion Annealing ◽  
Connection Strength ◽  
Ratio Effect ◽  
Steel Base ◽  
Contact Surfaces ◽  
Plastic Components ◽  
Base Contact

Contact surfaces preparation before cold cladding is one of the most important technological operations. A joint plastic components deformation of the of bimetal 1 according to OST 3-6648-91 and bimetal 3 according to OST 3-6649-91 CuZn10 brass - C22E steel - CuZn10 brass (according to EN standard) should be performed with the strongest possible compression to obtain the required layers connection strength, ensuring strip winding into a roll without delamination. We investigated influence of some factors on the bond strength of bimetal layers: surface hardening of contact surfaces, presence of an underlayer on a steel base, contact surfaces micro geometry, components heating temperature in the deformation zone, diffusion annealing after cladding and a bimetal layers thicknesses ratio effect. Cold cladding technological recommendations have been developed for manufacturing of bimetal 1 according to OST 3-6648-91 and bimetal 3 according to OST 3-6649-91 (CuZn10 brass - C22E steel - CuZn10 brass).

On effect of surface hardening on impact and abrasive wear resistance of Hadfi eld steel

2020 ◽  
pp. 252-255
Author(s):  
V.I. Bolobov ◽  
V.S. Bochkov ◽  
E.V. Akhmerov ◽  
V.A. Plashchinsky ◽  
E.A. Krivokrisenko E.A.
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Work Hardening ◽  
Surface Hardening ◽  
Cold Work ◽  
Abrasive Wear Resistance ◽  
Hadfield Steel ◽  
Mining Equipment ◽  
Effect Of Surface

On the example of Hadfield steel, as the most common material of fast-wearing parts of mining equipment, the effect of surface hardening by plastic deformation on their impact and abrasive wear resistance is considered. Wear test is conducted on magnetic ironstone as typical representative of abrasive and hard rock. As result of wear of initial samples with hardness of ∼200 HB and samples pre-hardened with different intensities to the hardness of 300, 337 and 368 HB, it is found that during the initial testing period, the initial samples pass the “self-cold-work hardening” stage with increase in hardness to ∼250 HB, which remains virtually unchanged during further tests; the hardness of the pre-hardened samples does not change significantly throughout the tests. It is established that the rate of impact-abrasive wear of pre-hardened samples is significantly (up to 1.4 times) lower than the original ones that are not subjected to plastic deformation, and decreases with increasing degree of cold-work hardening. Preliminary surface hardening by plastic deformation can serve as effective way to increase the service life of fast-wearing working parts of mining equipment.

scholarly journals The Contact Mechanics of Novikov’s Surface-Hardened Gearing during Running-in Process

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Alexey Beskopylny ◽  
Nikolay Onishkov ◽  
Viktor Korotkin
Keyword(s):  
Cold Deformation ◽  
Contact Fatigue ◽  
High Hardness ◽  
Contact Spot ◽  
The State ◽  
Contact Strength ◽  
Friction Forces ◽  
Contact Surfaces ◽  
Defective Surface ◽  
The Impact

The article is devoted to the analysis of the state of the contact surfaces of the higher kinematic pair in the general case of relative motion, that is, in the presence of rolling, sliding, and twisting, which is characteristic of Novikov’s circular-screw gears. The purpose of the work is to assess the impact of friction forces, the state of contact surfaces after tool processing, and the localization of the instantaneous contact spot on the level of contact—fatigue durability of gears. Power contact in the presence of geometric slippage of the mating surfaces leads to a significant change in the initial geometry and the mechanical properties of surface layers. In the existing methods of calculations of contact strength, the effect of running-in is investigated insufficiently, which leads to an incorrect result, especially for gear with high hardness of the teeth. In this work, the conditions of contact interaction close to the real requirements are studied on the basis of experimental material, numerical solution of the contact problem, determination of the terms of the contact areas of slip, and adhesion within the instantaneous spot. The shape of the instant contact spot has asymmetry and can be approximated by an ellipse with the introduction of a correction factor. The running-in period is of a plastic nature with cold deformation and reduction of the roughness of surfaces. As a result of the run-in period, the area of actual contact (tooth height) is increased by 2 or more times. It is not desirable to spread the area of contact at the area of adhesion that initiates the formation of pitting. The presence of defective surface area on the level of contact strength does not have significant influence, because of the running-in period, but increases the risk of spalling and brittle fracture.

scholarly journals Research into Correlation between the Lubrication Mode of Contact Surfaces and Dynamic Parameters of Turbo-Generator Transmissions

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Marek Kočiško ◽  
Petr Baron ◽  
Monika Telíšková ◽  
Jozef Török ◽  
Anna Bašistová
Keyword(s):  
Acoustic Emission ◽  
High Frequency ◽  
High Speed ◽  
Oil Quality ◽  
The State ◽  
Dynamic Parameters ◽  
High Frequency Vibration ◽  
Turbo Generator ◽  
Friction Mode ◽  
Contact Surfaces

The paper presents the results of an experimental study aimed at assessing the correlation between the measurement of dynamic parameters (vibration, high-frequency vibration, and acoustic emission) and the analysis of friction mode and the state of lubrication of the contact surfaces of two gearboxes in the turbo-generator assembly (high-speed single-body steam turbine—gearbox—generator) with the transmission power of no more than 50 MW. The analysis confirmed the assumption of a significant correlation of the monitored high-frequency vibration signal with the unsatisfactory engagement of the gear teeth. Through vibration analysis, an increased level of the tooth vibration component and vibration multiples with increased acoustic emission were identified in gearbox operation. The gear oil of one of the gearboxes examined showed a loss of additive elements in the real operation of the contact surfaces of the teeth engagement. The trend analysis confirmed the complexity of the monitored transmission operation in terms of the friction mode and the influence of the oil quality on the state of the tooth flank microgeometry.

scholarly journals Deformation and forces when compressing spherical particle

2020 ◽  
Vol 329 ◽  
pp. 03004
Author(s):  
Vladimir Fedyaev ◽  
Marat Faskhutdinov ◽  
Igor Sidorov
Keyword(s):  
Plastic Deformation ◽  
Spherical Particle ◽  
Particle Contact ◽  
Contact Surfaces ◽  
Over Time

Plastic deformation of a spherical particle under the action of a roller is considered. In order to obtain engineering evaluations, a number of assumptions are made. As a result, the relationships for calculating the lengths characterizing the dynamics of the dimensions change of the particle contact surfaces with the roller and the substrate over time are found. After that, the pressure and the compression forces acting on the particle are determined.

A Micro-Contact Model for Boundary Lubrication With Lubricant/Surface Physiochemistry

2002 ◽  
Vol 125 (1) ◽  
pp. 8-15 ◽  
Author(s):  
H. Zhang ◽  
L. Chang ◽  
M. N. Webster ◽  
A. Jackson
Keyword(s):  
Plastic Deformation ◽  
Friction Coefficient ◽  
Oxide Layer ◽  
Contact Pressure ◽  
Friction Force ◽  
Boundary Lubrication ◽  
The State ◽  
Surface Generation ◽  
Contact Friction ◽  
Flash Temperature

A model is developed to study the tribological behavior of sliding micro-contacts. It provides a building block to the modeling of tribo-contacts in boundary lubrication. Three contact variables are calculated at the asperity-level by relating them to the state of contact and the state of asperity deformation. These variables include micro-contact friction force, load carrying capacity and flash temperature. The deformation of the contacting asperity is either elastic, elasto-plastic, or fully plastic. Furthermore, the asperity may be covered by the lubricant/additive molecules adsorbed on the surface, protected by a surface oxide layer or other chemical reaction films, or in direct contact with no boundary protection. The possibility of the contact in each of these three states is represented by a corresponding contact probability. A numerical method is developed to determine the contact state and contact variables in the course of an asperity-to-asperity collision. The asperity flash temperature, which governs the kinetics of lubricant/surface adsorption/desorption, is first calculated by integrating the Jaeger equation over the contact area and in time. Then, the probability of contact covered by an adsorbed film is determined using the Volmer adsorption isotherm, and the probability of contact protected by the oxide layer is estimated using a classical wear theory. For elastic/elasto-plastic deformation of the asperity, the friction coefficient is given by the linear combination of the friction coefficients of the three contact states with their contact probabilities as the weighting factors. For fully plastic deformation of the asperity, the contact pressure and friction force become dependent of each other. The shear stress is approximated by a linear function of the contact probabilities, and the contact pressure and friction coefficient then calculated. Meanwhile, the influence of fresh surface generation due to plastic flow on the contact probabilities is also modeled. Insights are provided into the asperity collision through numerical studies of a sample problem. In addition, parametric studies are carried out to analyze the effects of lubricant and surface parameters on the micro-contact severity and its load capacity.

Hardening Process by Complex Local Deformation Investigation

2016 ◽  
Vol 870 ◽  
pp. 149-158 ◽  
Author(s):  
V.A. Golenkov ◽  
S.J. Radchenko ◽  
I.M. Gryadunov
Keyword(s):  
Plastic Deformation ◽  
Surface Hardening ◽  
Local Deformation ◽  
Laboratory Research ◽  
Experimental Equipment ◽  
Local Loading ◽  
Sliding Bearings ◽  
Hardening Process ◽  
Equipment Construction ◽  
Inner Surface

The article considers a new method of sliding bearings inner surface hardening by plastic deformation in complex local loading of deformation zone conditions. The main aspects of experimental equipment construction and experimental research preparation are reviewed. The laboratory research results are presented.

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