scholarly journals Laser hardening of tools with the use of the beam

2018 ◽  
Vol 19 (6) ◽  
pp. 636-639
Author(s):  
Irena Nowotyńska ◽  
Stanisław Kut ◽  
Krzysztof Kogut
Keyword(s):  
Surface Layer ◽  
Laser Beam ◽  
Beam Splitter ◽  
Hardened Layer ◽  
Original Method ◽  
Laser Hardening ◽  
New Method ◽  
Laser Head ◽  
Simultaneous Heating

The main problem occurring during the laser hardening of tools is the lack of continuity and diversity of surface layer properties as a result of the use of many parallel hardening paths. As a consequence, there may be a forgiven or under-hardened area between successive paths. The paper presents the original method of laser hardening of tools, especially bending, using a laser beam splitter. Such a hardening method enables simultaneous heating and tempering of the tool corner and the surfaces adjoining it at the desired width in one pass with the same parameters. As a consequence, the hardened layer is uniform on the surface of the corner and adjacent surfaces, i.e. without forgiven or unhardened areas. The use of this method requires equipping the hardening laser head with a divider, whose task is to distribute the laser beam to separate parts of the beam with adjustable width by means of appropriately placed mirrors. The new method of hardening not only eliminates the problem of so-called hardening marks created as a result of laser hardening, which directly affects the quality, durability and durability of the tool, but is also much more efficient and also beneficial for economic reasons.

scholarly journals Investigation of the Technological Possibility of Laser Hardening of Stainless Steel 14Cr17Ni2 to a Deep Depth of the Surface

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 5
Author(s):  
Vladislav Somonov ◽  
Igor Tsibulskiy ◽  
Ruslan Mendagaliyev ◽  
Alexander Akhmetov
Keyword(s):  
Stainless Steel ◽  
Laser Beam ◽  
Laser Processing ◽  
Quantitative Estimation ◽  
Hardened Layer ◽  
Laser Hardening ◽  
Structural Components ◽  
Technological Possibility ◽  
Deep Depth ◽  
Number Of Passes

The article presents the results of a research of the process of laser hardening of steel 14Cr17Ni2 (AISI 431) by radiation of a high-power fiber laser LS-16. Assessment of the theoretically possible maximum depth in laser processing without additional beam transformations, the use of additional coatings and devices were shown. The results of experiments on increasing the depth of the hardened layer during laser processing by using scanning of the laser beam and optimally selected mode parameters without scanning are demonstrated. The influence of the number of passes on the depth of the hardened layer is investigated. The microstructure of hardened samples was studied and quantitative estimation of structural components was carried out. The microhardness of hardened samples at different modes of laser hardening was measured.

Hardness of the Powder Coating PG-CP4 Applied to Steel 40H13 and Subjected Laser Treatment

2021 ◽  
Vol 410 ◽  
pp. 456-462
Author(s):  
Vladimir G. Gusev ◽  
Valentin V. Morozov ◽  
Dmitry I. Gavrilov
Keyword(s):  
Surface Layer ◽  
Laser Beam ◽  
Laser Treatment ◽  
Protective Coating ◽  
Factor Model ◽  
Radiation Power ◽  
Heat Removal ◽  
Powder Coating ◽  
High Rate ◽  
Laser Head

The article examines the hardness of the coating made of PG-CP4 powder. Plasma powder deposition was performed to samples made of 40H13 steel and then the samples treated with a laser beam. A multi-factor model was established that relates the hardness of the protective coating to the radiation power W, the longitudinal feed Spr of the laser beam, and the distance L from the protective casing of the laser head to the treated surface. Depending on the laser treatment modes, coating was in a state of complete, partial reflow or its absence. Full reflow is characterized by the adhesion of the filler material to the substrate, by maximum hardness of HRC 51.2–56.6 and no defects. In the absence of reflow, gas sinks, transverse microcracks, detachments, and other defects were found in the coating material, and the hardness decreased to HB 125–212. An increase in W and a decrease in Spr lead to increases the hardness of the treated coating, which is explained by an increase in the specific heat flux supplied to the coating per unit time, and a high rate of heat removal deep into the surface layer of 40H13 steel. The thickness of the surface layer with increased hardness ranged from 0.1 to 1.5 mm. Based on the multi-factor model, laser processing modes are controlled to ensure the required values of the protective coating hardness. The research results are recommended for use in enterprises that implement laser technologies and develop modern laser systems.

Effect of Additional Shear Strain Layer on Microstructure and Tensile Strength of Fine Wire

2007 ◽  
Vol 340-341 ◽  
pp. 525-530 ◽  
Author(s):  
Satoshi Kajino ◽  
Motoo Asakawa
Keyword(s):  
Tensile Strength ◽  
Surface Layer ◽  
Tensile Test ◽  
Shear Strain ◽  
Crystal Orientation ◽  
Hardened Layer ◽  
High Tensile Strength ◽  
Center Layer ◽  
Fine Wire ◽  
Strain Layer

The mechanical and electrical applications of fine wires (D = 0.1 mm) has become more widely spread. In general, it is well known that fine drawn wires have high tensile strength while maintaining ductility. It has been determined that a hardened layer of around 0.04 mm in depth, referred to as the “additional shear strain layer,” is generated beneath the surface layer of the wire, and this additional shear strain layer affected the tensile strength of the fine wire. As an origin of this phenomenon, it was ascertained that the microstructure of surface layer was finer than that of center layer. The purpose of this paper is to investigate the effect of die angle on the microstructure and the tensile strength of the additional shear strain layer. The tensile test was performed as the surface layer was thinned by electro-polishing, and the crystal orientation and the crystal grain were measured via EBSD. As a result, it was ascertained that die angle affected the tensile strength and crystal grain refinement of the additional shear stray layer.

Thermal Stability of 40Cr Steel with Surface Nanocrystallization

2006 ◽  
Vol 510-511 ◽  
pp. 434-437 ◽  
Author(s):  
Yu Liang Liu ◽  
Tian Ying Xiong ◽  
Ke Yang
Keyword(s):  
Thermal Stability ◽  
Surface Layer ◽  
Nanostructured Materials ◽  
High Thermal Stability ◽  
New Method ◽  
Nanostructured Surface ◽  
Surface Nanocrystallization ◽  
Nanostructured Layer ◽  
40Cr Steel ◽  
Thermal Stability Of

Surface Nanocrystallization(SNC) is a new method of fabricating nanostructured materials while thermal stability is an important problem for the application of nanostructured materials. A nanostructured layer was fabricated on the surface of 40Cr steel by Supersonic Particles Bombarding method, and the variation of microstructure and microhardness of nanostructured layer was studied. Nanostructured surface layer showed high thermal stability.

scholarly journals Features of the Surface and Subsurface Waves Application for Ultrasonic Evaluation of Physicomechanical Properties of Solids. Part 2. Strenghtned Inhomogeneous Surface Layer

2019 ◽  
Vol 10 (1) ◽  
pp. 69-79
Author(s):  
A. R. Baev ◽  
A. L Mayorov ◽  
N. V. Levkovich ◽  
M. V. Asadchaya
Keyword(s):  
Experimental Data ◽  
Surface Layer ◽  
Spatial Distribution ◽  
Surface Wave ◽  
High Frequency ◽  
Hardened Layer ◽  
Gray Iron ◽  
Physicomechanical Properties ◽  
Inhomogeneous Surface ◽  
Ultrasonic Evaluation

The propagation of a pulsed signal of a surface wave over an object with a non-uniform surface layer, obtained, for example, as a result of surface hardening, with structural damage, is accompanied by the dispersion of the velocity of the wave carrying important information about the parameters of such a layer. The aim of the work is to study the relationship between the acoustic parameters of a pulsed acoustic signal of a surface and subsurface waves and the surface layer of steel specimens hardened by high-frequency hardening, and gray iron-chill. Features of the surface and subsurface waves application for ultrasonic evaluation of physicomechanical properties of solids. Strenghtned inhomogeneous surface layer.A brief analysis of the known works on determining the depth of hardened surface layers by various methods, including high-frequency hardening, cementation, etc., is carried out. Based on the Oulder integral expression. The dependence connecting the wave velocity, its frequency, the depth of the hardened layer and the spatial distribution of hardness represented as a step with a changing slope of its side surface simulating the transition zone of the hardened layer are calculated.Using the pulse method and low-aperture transducers with a frequency of 1−3.8 MHz, the dependences of the surface wave velocity on the cutting height of a layer hardened by HDTV hardening are obtained. A comparison of experimental data and calculations of the theoretical model showed a good qualitative correspondence between them, demonstrate a high «sensitivity» of the method in relation to the nature of the change in hardness over the depth of the hardened layer. It is shown that the proposed approach is promising for solving the inverse problem of restoring the spatial distribution of hardness based on experimental data.The goniometric method was approbated to determine the dependence between amplitude-angle characteristics and depth of the surface steel layers hardened by high-frequency hardening and depth of hardened gray iron specimens layer – with chill. It is shown that the optimal angle corresponding maximum of excited surface wave amplitude in steel specimens is decreasing up to 24–26'vs. hardened depth layer. But when the tested specimens from cast iron this angle decreasing is nearly of 6°. Recommendations on the use of research results in practice are given.

scholarly journals Experimental and Numerical Analysis of the Depth of the Strengthened Layer on Shafts Resulting from Roller Burnishing with Roller Braking Moment

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5844
Author(s):  
Marek Kowalik ◽  
Tomasz Trzepieciński ◽  
Leon Kukiełka ◽  
Piotr Paszta ◽  
Paweł Maciąg ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Rolling Resistance ◽  
Original Method ◽  
Pressure Force ◽  
Roller Burnishing ◽  
Braking Torque ◽  
Burnishing Process ◽  
Deformed Layer ◽  
Dependence Relationship

The article presents the results of investigations into the depth of the plastically deformed surface layer in the roller burnishing process. The investigation was carried out in order to obtain information on the dependence relationship between the depth of plastic deformation, the pressure on the roller and the braking torque. The research was carried out according to the original method developed by the authors, in which the depth of plastic deformation is increased by applying a braking torque to the burnishing roller. In this method, it is possible to significantly increase (up to 20%) the depth of plastic deformation of the surface layer. The tests were carried out on a specially designed device on which the braking torque can be set and the force of the rolling resistance of the roller during burnishing can be measured. The tests were carried out on specimens made of C45 heat-treatable carbon steel. The dependence of the depth of the plastically deformed surface layer was determined for a given pressure force and variable braking moments. The depth of the plastically deformed layer was measured on the deformed end face of the ring-shaped samples. The microhardness in the sample cross-section and the evolution of the microstructure were both analysed.

scholarly journals INCREASING THE EFFICIENCY OF SURFACE STRENGTHENING OF METAL PRODUCTS BY COMBINED THERMODEFORMATION PROCESSING

2020 ◽  
pp. 103-110
Author(s):  
Oleksandr Danyleiko ◽  
Vitaliy Dzhemelinskyi ◽  
Dmytro Lesyk ◽  
Artemii Bernatskyi
Keyword(s):  
Surface Layer ◽  
Laser Beam ◽  
Surface Hardening ◽  
Thermal Deformation ◽  
Experimental Studies ◽  
Numerical Control ◽  
Surface Plastic ◽  
Beam Diameter ◽  
Metal Products ◽  
Deformation Surface

The article discusses the prospects of using combined thermal deformation surface processing to improve the performance properties of metal products. There is a new method of thermal deformation surface hardening (shot peening (SP) followed by laser heat treatment (LHT)) for tools and crown housings operating under difficult conditions proposed. For carrying out experimental studies, flat samples of 30KhGSA steel and steel 45 were selected. Preliminary hardening and finishing with static or dynamic methods of surface plastic deformation were carried out on a modernized installation based on a DYNAMITE 2800 numerical control machine, and SP was implemented on industrial equipment. Laser surface hardening of the samples was carried out in single passes with a sample moving speed of 300...500 mm/min with a laser beam diameter of 7.3 mm and a laser power of 1 kW using the ROFIN-SINAR DY 044 technological unit. The optimal regimes of surface hardening are determined under the deformation action of a gas-dynamic flow with solid particles and thermal action by a laser beam to obtain maximum values ​​of hardening depth and hardness. In particular, with SP, the gas-feed stream feed pressure is 0.5 MPa, the processing time is 1 min, regardless of the type of material. The optimal laser beam power is 1 kW at a sample travel speed of 300 mm/min. There are the results of experimental studies of the change in the hardening depth as a function of time and pressure after SP, the speed of movement of the treated sample from carbon steel 45 and medium alloyed steel 30KhGSA after LHT and combined SP+LHT, and also the distribution of microhardness over the depth of the hardened layer presented. It is revealed that the combined SP+LHT of 30 KhGSA steel at optimal modes forms 1.5 times (1.3 mm) greater depth of the strengthened surface layer in comparison with LHT, while providing the surface layer hardness of ~5400 MPa.

scholarly journals The histology of the cell wall, with special reference to the mode of connexion of cells. preliminary communication

1898 ◽  
Vol 62 (379-387) ◽  
pp. 100-112 ◽  
Keyword(s):  
Cell Wall ◽  
Cell Membrane ◽  
Special Reference ◽  
Original Method ◽  
New Method ◽  
Endosperm Tissue ◽  
Preliminary Communication

Since 1883 I have repeatedly endeavoured to discover some refined and generally applicable method by means of which the fine fibrillæ, or “connecting threads,” traversing the cell membrane might be identified with certainty, and the fact of their existence settled beyond dispute. I was also anxious to be in a position to investigate the development of the threads in endosperm tissue. My researches met with little encouragement until 1894, when I succeeded in finding a new method, by means of which I obtained excellent results with the young developing endosperm tissue of Tamus communis . This I have further elaborated, so that either the original method, or modifications of it, can be applied to tissues generally.

Fiber Blending Irregularities in Cross Sections and on Yarn Surfaces in Relation to Yarn Properties

1988 ◽  
Vol 58 (5) ◽  
pp. 291-298 ◽  
Author(s):  
Izabella Krucińnska
Keyword(s):  
Surface Analysis ◽  
Cross Sections ◽  
Original Method ◽  
New Method ◽  
Cross Sectional ◽  
Yarn Properties ◽  
Yarn Surface ◽  
Fiber Blending

An analysis of fiber blending irregularities is presented in relation to the disturbances of blend yarn properties resulting from these phenomena. Fiber blending irregularities were assessed using the original method of yarn surface analysis and a new method of yarn cross-sectional division. These methods correctly reflect the disturbances in the mechanical and aesthetic yarn properties resulting from non-uniform mixing of constituent fibers.

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