Wyniki wyszukiwania - BazTech

1

Influence of laser treatment on properties of high speed tool

Ulewicz R., Nový F.

Technical Transactions

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2018

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Vol. 115, iss. 10

195--200

EN

The paper presents the results of heat treatment tests of HS6-5-2 high speed steel with laser working in continuous mode. The tests used steel in the delivery state as well as steel after fluid treatment aimed at diffusion enrichment of the surface layer with carbon and nitrogen. The aim of the research is to determine changes in the structure of steel enriched with carbon and nitrogen and then subjected to the impact of the laser beam.

PL

W artykule przedstawiono wyniki badań obróbki cieplnej laserem pracującym w trybie ciągłym stali szybkotnącej HS6-5-2. W badaniach wykorzystano stal w stanie dostarczenia, jak również stal po fluidalnej obróbce mającej na celu wzbogacenie dyfuzyjne warstwy wierzchniej w węgiel i azot. Celem badań jest określenie zmian struktury stali wzbogaconej w węgiel i azot, a następnie podanej oddziaływaniu wiązki lasera.

2

Fatigue lifetime of 20MnV6 steel with holes manufactured by various methods

Bokůvka O., Jambor M., Trško L., Nový F., Lisiecka B.

Production Engineering Archives

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2018

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Vol. 19

3--5

EN

In this paper, the authors publish their own experimental results of the examination of the different holes (milled, drilled and drilled + shot peened) on the fatigue lifetime of 20MnV6 steel. The experiments were carried out at low-frequency loading (f = 10 Hz, pulsating tension loading) in the region from N = 2×105 up to N = 2×106 cycles. The best fatigue properties were obtained in the parts with drilled + shot peened holes.

3

Quality Management in the Process of Selection of Material for Dump Truck Elements

Ulewicz R., Nový F.

Multidisciplinary Aspects of Production Engineering

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2018

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Vol. 1, Iss. 1

665--671

EN

The article presents the problem of quality management in the process of material selection for structural elements of a car dump truck. The study took into account the classical management pyramid and there was used the optimization method (generalized objective function). The center that manages the process of production / assembly of the dump truck should be the level of organization that has the highest degree of processing of required information and making strategic decisions in this respect. The design process of structural elements is carried out primarily in terms of the ability to provide adequate physical and mechanical properties in the process. There is a very strong tendency to reduce the own weight of the semi-trailers by increasing the weight of the load. This is an important criterion from the point of view of the economics of operation of technical facilities of this type. The article presents the results of the application of a generalized objective function in the field of material selection for construction elements of a dump truck. The analysis includes structural elements made of S355 steel and Hardox 400 and 450 fine-grain steel.

4

Wpływ obróbki strumieniowo-ściernej i kulowania na wytrzymałość zmęczeniową stali konstrukcyjnych

Miková K., Guagliano M., Trško L., Bokůvka O., Żórawski W., Nový F.

Inżynieria Powierzchni

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2014

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nr 1

3--6

PL

Proces obróbki strumieniowo-ściernej jest najczęściej stosowaną metodą przygotowania powierzchni bezpośrednio przed procesem natryskiwania cieplnego. Prowadzone są również badania nad innymi metodami, jak: kulowanie, wykorzystanie strumienia wody, obróbka laserowa lub chemiczna. W artykule przedstawiono wyniki badań eksperymentalnych dotyczących wpływu obróbki strumieniowo-ściernej i kulowania na wytrzymałość zmęczeniową stali X70 oraz C45. Wyniki badań wytrzymałości zmęczeniowej obydwu stali wykazały pozytywny wpływ umocnienia warstwy wierzchniej w efekcie obróbki kulowaniem oraz obróbki strumieniowo-ściernej, co spowodowało podwyższenie ich granicy wytrzymałości zmęczeniowej.

EN

Shot blasting process is the most often used method of surface preparation directly before metallic spraying process. There are some investigations of other methods such as: shot-peening, water stream process, laser treatment or chemical treatment. In the paper are presented results of experimental tests of the effect of shot-blasting and shot-peening on the fatigue strength of X70 and C45 steels. Results of fatigue strength tests for both steels proved a positive effect of the surface layer strengthening as a result of shot-peening and shot-blasting processes involved higher fatigue strength limits.

5

Comparison of the properties of composite organic railway brake blocks of type K with cast iron brake block P10

Hriňák J., Nový F., Řezníček R., Kalinčák D.

Logistyka

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2012

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nr 3

EN

This contribution compares the composite organic brake blocks of type K with cast iron brake block, which is currently used most often. In the article is processed analyze of friction materials used for railway brakes. There are also processed the materials microscopic analysis of individual types of brake blocks using the light microscopy as well as their friction characteristics during braking on the brake test bench UIC and comparison of individual results.

6

Influence of shot peening on the EN-AW-6082 Al alloy fatigue resistance

Nový F., Chalupová M., Škorík V., Bokůvka O.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne

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2011

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Z. 16

73-80

EN

The influence of shot peening on fatigue resistance of the wrought EN-AW-6082-T6 aluminium alloy was investigated in the very high cycle region. Specimens with as-machined and shot peened surfaces were subjected to high frequency fatigue loading. Shot peening process led to the formation of compressive residual stresses in the surface layer and effectively improved the fatigue resistance. The tests results showed that the fatigue strength for shot peened specimens is much higher than that for as-machined specimens in the all investigated range of cycles.

7

Influence of oxynitride layer on the deep-drawing sheets fatigue properties

Palček P., Nový F., Mintách R., Chalupová M.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne

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2011

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Z. 16

87-94

EN

The paper deals with the influence of nitrooxidation on fatigue lifetime of low carbon deep drawing steel DC 01 EN 10130 - 91 delivered in the form of sheets. Fatigue results were determined at high - frequency fatigue machine (f ≈ 20 kHz), at T = 20 š3°C using bending loading with stress ratio R = -1. It was found that the nitrooxidation process has positive effect on the fatigue lifetime compared with base material. The structure analyze and measurement of microhardness of steel sheets after nitrooxidation process was also performed. The Fe2O3 and Fe3O4 as well as the layer of ε - phase (Fe3N) were identified in surface and subsurface layers and nitrides Fe4N and Fe16N2 were segregated in ferritic matrix. The maximum microhardness was determined in diffusion area containing the slight nitrides of Fe16N2 uniformly distributed in ferritic matrix.

8

Fatigue resistance of spring steel at high-frequency cyclic loading

Bokůvka O., Palček P., Mintách R., Nový F.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2011

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z. 4/85

13--16

EN

High-frequency cyclic loading (f = 20 kHz, T = 20 ± 5 °C, R = -1) is used to determine near threshold crack growth rates, da/dN = f (Ka) and the threshold stress intensity factor amplitude Kath in two different leaf spring steels used in the transportation industry. The leaf springs are usually made of high-strength low-alloyed structural steels (with ultimate strength from Rm = 1300 MPa to 1650 MPa) produced according to different technologies; the trend is use steels with increasingly high tensile strength. The obtained results however confirm that an increase in tensile strength in leaf spring steels reduced values of Kath and increase the fatigue crack growth rates; hence the highest sensitivity to initial defects and lowest fatigue cracks resistance.

PL

Wysokoczęstotliwościowe obciążenie cykliczne (f = 20 kHz, T = 20 ± 5 °C, R = -1) jest wykorzystywane do określenia szybkości wzrostu progu pęknięcia, da / dN = f (Ka) oraz progu amplitudy współczynnika intensywności naprężeń Kath dla dwóch różnych stali wykorzystywanych do budowy resorów piórowych stosowanych w branży transportowej. Resory piórowe są zwykle wykonane z wysokiej wytrzymałości niskostopowych stali konstrukcyjnych (z wytrzymałością Rm = 1300 MPa do 1650 MPa) produkowanych według różnych technologii. Aktualnym trendem jest stosowanie stali z coraz większą wytrzymałością na rozciąganie. Uzyskane wyniki potwierdzają jednak, że wzrost wytrzymałości na rozciąganie w stalach wykorzystywanych na resory piórowe zmniejszenie wartość Kath i zwiększa szybkość wzrostu pęknięcia zmęczeniowego, stąd są one bardzo wrażliwe na wady początkowe i mają najniższą odporność na pękanie zmęczeniowe.

9

Evaluation of materials fatigue properties by ultrasonic frequencies

Bokůvka O., Nový F., Palček P., Buršák M., Valovičová V.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne

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2009

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Z. 13

56--62

EN

The information about an experimental ultrasonic testing equipment, used specimens incl. the characteristic examples about fatigue of structural materials resistance – fatigue lifetime in the ultra-high-cycle region, rate of the long fatigue crack growth in the near - threshold area and threshold values are stated in this work. The knowledge and results are utilizable in the field of materials engineering and threshold states of materials.

10

Gigacycle fatigue at high-frequency loading

Bokůvka O., Nový F., Chalupová M., Nicoletto G.

Diagnostyka

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2008

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nr 4(48)

53-56

EN

In this work there are information about an experimental high-frequency testing apparatus and specimens enable to determine the fatigue properties in the ultra-high-cycles region (gigacycle fatigue) and the rates of long fatigue cracks growth in near-threshold areas. The selected characteristic examples about fatigue resistance of various structural materials are presented. The results are utilizable in the field of material engineering and threshold states of material.