Wyniki wyszukiwania - Biblioteka Nauki

1

Topography of X39Cr13 steel surface after heat and surface treatment

100%

Gwoździk M. , Nitkiewicz Z.

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2009

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tom Vol. 39, nr 4

853-857

EN

The paper presents results of surface condition examinations of martensitic X39Cr13 steel subject to heat and surface treatment (plasma nitriding). The heat treatment consisted of compressed nitrogen quenching from 1050 °C (1323 K) and two-hours tempering at 300 °C (573 K) and 620 °C (893 K) for specimens subject to nitriding. The plasma nitriding was carried out in an ion-nitriding installation with cooled anode, at temperature of 460 °C (733 K), at pressure of 150 Pa and during t = 20 h (72 ks); 25%N2+75%H2 was used as the reactive atmosphere. Specimens surface was examined using a profilographometer designed for surface 2D and 3D examinations using a contact method. Surface topography measurements were carried out on specimens taken from 1 mm thick sheet. 1.5 mm×1.5 mm surface was the measurement area. The sampling interval in X and Y axis was 1 žm, while the measuring speed was 0.5 mm/s. The studies carried out allowed evaluating the conditions of examined steel surface through the comparison of stereometric parameters of the surface.

2

Plasma Nitriding as a Prevention Method Against Hydrogen Degradation of Steel

100%

Ćwiek J.

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2009

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tom Vol. 9, nr 1(19)

4-13

EN

Aim of this paper is evaluation of susceptibility of plasma nitrided structural steel to hydrogen absorption and degradation. Structural steel, nitrided at glow discharge in the gas mixture of various N2, H2, Ar content was subjected to cathodic hydrogen charging in acid solution simulating the aged engine oil. The effect of the nitrided layers on the hydrogen transport and on the irreversible trapping was evaluated by the measurements of the hydrogen permeation rate and by the vacuum extraction, respectively. Surfaces with modified layers were examined with the use of a scanning electron microscope (SEM) before and after hydrogen permeation tests. In the presence of the not defected compact nitride layer, no hydrogen permeation through the steel has been stated under the experimental conditions. Absorbed hydrogen was accumulated within this layer. Using the atmosphere of the higher nitrogen to hydrogen ratio at plasma assisted nitriding provides the formation of thin compact nitride zone, highly protective against corrosion and hydrogen degradation.

3

The properties and wear resistance of the CrN PVD coatings

88%

Poloc-Rubiniec M. , Dobrzański L. , Adamiak M.

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2008

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tom Vol. 30, nr 2

165-171

EN

Purpose: The aim of the paper is comparison of the mechanical properties and wear resistance of the monolayer CrN PVD coatings deposited onto heat treated and plasma nitrited X37CrMoV5-1 type hot work tool steel. Design/methodology/approach: The microhardness tests of the PVD coatings were made on the dynamic ultra-microhardness tester. The surfaces' thopography and the structure of the PVD coatings was observed on the scanning electron microscopy. The evaluation of the adhesion of coatings to the substrate was made using the scratch test. The wear and friction tests were performed on a pin-on-disc device at the room temperature and at the temperature of 500°C. The friction coefficient between the ball and disc was measured during the test. Findings: In case of the CrN coating deposited onto the X37CrMoV5-1 nitrided hot work steel a very good adhesion has been revealed to the substrate material in comparison to the CrN coating deposited onto the heat treated hot work steel. Taking into account the results of measurements, one can state that the lowest wear at certain conditions at both room and elevated temperatures displays the CrN coating deposited onto plasma nitrited X37CrMo V5-1 hot work steel type. Practical implications: The investigation results will provide useful information to applying the plasma nitriding and the CrN PVD coatings for the improvement of the wear resistance of tools made from hot work steels. Originality/value: The paper contributes to better understanding of the structure, mechanical properties, adhesion and the wear resistance at the elevated temperature (500°C) of the monolayer CrN PVD coating deposited onto the heat treated and plasma nitrited hot work tool steel.

4

Investigation of surface properties of high temperature nitrided titanium alloys

75%

Koyuncu E. , Kahraman F. , Karadeniz O.

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2008

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tom Vol. 29, nr 1-2

50-62

EN

Titanium and its alloys have very attractive properties for many industries. But using of titanium and its alloys are very low in mechanical engineering applications because of poor tribological properties. In this study, surface modification of Ti6Al4V titanium alloy has been made with various temperatures by plasma nitriding process. Plasma nitriding treatment has been performed in 80% N2-20% H2 gas mixture, for treatment times of 2-15 h at the temperatures of 700-1000 degree C. Surface properties of plasma nitrided Ti6Al4V alloy was examined by metalographic inspection, X-Ray difraction and vichers hardness. Two layers were determined by optic inspection on the samples that called compound and diffusion layers. Compound layer contain TiN and Ti2N nitrides, XRD results support in this formations. Maximum hardness has been obtained at 10h treatment time and 1000 degree C treatment temperature. Micro hardness tests showed that hardness properties of the nitrided samples depend on treatmant time and temperature.

5

Azotowanie jarzeniowe żeliwa wermikularnego w aspekcie wzrostu odporności na zużycie przez tarcie

75%

Sobiecki J. R. , Wierzchoń T.

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2008

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tom Nr 4

16-20

PL

W artykule przedstawiono wpływ azotowania w warunkach wyładowania jarzeniowego żeliwa wermikularnego na mikrostrukturę i właściwości użytkowe takie jak mikrotwardość i odporność na zużycie przez tarcie. Zastosowanie temperatury azotowania 580°C w czasie 8 godzin prowadzi do wytworzenia strefy związków o grubości około 8 žm i strefy dyfuzyjnej o grubości ponad 200 žm. Azotowanie zdecydowanie obniża zużycie Liniowe żeliwa jak również intensywność zużycia, co skutkuje podwyższeniem odporności na zużycie przez tarcie. Po procesie azotowania jarzeniowego obserwuje się kilkukrotne zmniejszenie początkowego i końcowego współczynnika tarcia. Mikrotwardość powierzchniowa wzrasta do wartości 570 HV 0,05.

EN

It is discussed in the paper glow-discharge assisted nitriding of vermicular cast iron affect the microstructure, and useful properties like microhardness and wear resistance. The application of 580°C during 8 hours of experiment results in 8 žm of compound lager and above 200 žm the diffusion zone. Plasma nitriding process significantly decreases the linear wear and the wear intensity of the substrate and increases the wear resistance. It also reduces the value of initial and final friction coefficients several limes. The microhardness increases to the 570 HV 0,05.

6

Investigation of surface properties of high temperature nitrided titanium alloys

75%

Koyuncu E. , Kahraman F. , Karadeniz Ö.

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2009

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tom Vol. 37, nr 2

434-441

EN

Purpose: The purpose of paper is to investigate surface properties of high temperature nitrided titanium alloys. Design/methodology/approach: In this study, surface modification of Ti6Al4V titanium alloy was made at various temperatures by plasma nitriding process. Plasma nitriding treatment was performed in 80% N2-20% H2 gas mixture, for treatment times of 2-15 h at the temperatures of 700-1000°C. Surface properties of plasma nitrided Ti6Al4V alloy were examined by metallographic inspection, X-Ray diffraction and Vickers hardness. Findings: Two layers were determined by optic inspection on the samples that were called the compound and diffusion layers. Compound layer contain TiN and Ti2N nitrides, XRD results support in this formations. Maximum hardness was obtained at 10h treatment time and 1000°C treatment temperature. Micro hardness tests showed that hardness properties of the nitrided samples depend on treatment time and temperature. Practical implications: Titanium and its alloys have very attractive properties for many industries. But using of titanium and its alloys is of very low in mechanical engineering applications because of poor tribological properties. Originality/value: The nitriding of titanium alloy surfaces using plasma processes has already reached the industrial application stage in the biomedical field.

7

Comparison of the structure, properties and wear resistance of the TiN PVD coatings

75%

Polok-Rubiniec M. , Dobrzański L. A. , Lukaszkowicz K. , Adamiak M.

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2008

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tom Vol. 27, nr 1

87-90

EN

Purpose: The aim of the paper was to compare the structure, mechanical propeties, adhesion and wear resistance of the monolayer TiN PVD coatings deposited onto heat treated and plasma nitrided hot work tool steel X37CrMoV5-1. Design/methodology/approach: The microhardness tests of the PVD coatings were made with use of a dynamic ultra-microhardness tester. The topography of the surface and the structure of the PVD coatings was observed with use of scanning electron microscopy. The evaluation of the adhesion of coatings to the substrate was made with use of the scratch test. The wear and friction tests were performed with use of a pin-on-disc device at the room temperature and at the temperature of 500*C. Findings: IIn case of the TiN coating deposited onto the nitrided hot work steel X37CrMoV5-1 a very good adhesion to the substrate has been revealed in comparison with the TiN coating deposited onto the heat treated hot work steel. Taking into account the results of measurements, one can state that the lowest wear at certain conditions at both room and elevated temperatures is characteristic for the TiN coating deposited onto plasma nitrided hot work steel type X37CrMoV5-1. Practical implications: The results of the investigations provide useful information for applying the plasma nitriding and the TiN PVD coating for the improvement of the mechanical properties and wear resistance of tools made from hot work steels. Originality/value: The paper contributes to better understanding of the adhesion and wear resistance at the elevated temperature up to 500*C of the monolayer TiN PVD coating deposited onto the heat treated and plasma nitrided hot work tool steel.

8

Efektywne wykorzystanie energii elektrycznej w piecach jarzeniowych

63%

Niedbała R.

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2008

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tom R. 84, nr 5

71-74

PL

Zadawalające rezultaty uzyskiwane w technologiach z udziałem wyładowania jarzeniowego spychały na dalszy plan całościowe rozwiązania urządzeń i planowanie procesów energetycznych. W referacie przedstawiono cechy wyładowania jarzeniowego anormalnego w aspekcie procesów azotowania detali o różnorodnej geometrii. Podano dostrzeżone związki pomiędzy charakterystykami energetycznymi wyładowania jarzeniowego a stratami cieplnymi. Na podstawie zebranych doświadczeń określono wzajemne współdziałanie układów zasilających z odpowiednimi konstrukcjami pieców, które mogą przyczynić się do oszczędnego gospodarowanie energią elektryczną podczas długotrwałych procesów technologicznych.

EN

Satisfying results obtained in technologies using the glow discharge processes, played down the globar constructional solutions of installations and planning of processes from the point of view of rational use of energy. In the paper the features of abnormal glow discharge, applied to nitriding parts of various shapes, are presented. The observed relations between energy characteristics of glow discharge and heat losses were given. On the ground of experiments was determined the cooperation of supply units with different constructions of furnaces, that could make possible the saving of electric energy used at longlasting technological processes.

9

Comparison of the adhesion and wear resistance of the PVD coatings

63%

Polok-Rubiniec M. , Dobrzański L. A. , Adamiak M.

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2007

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tom Vol. 20, nr 1-2

279-282

EN

Purpose: of the paper was comparison of the adhesion and antiwear properties of the multilayer TiN/(Ti,Al)N PVD coatings deposited onto heat treated and plasma nitrided X37CrMoV5-1 type hot work tool steel. Design/methodology/approach: Hardness test of the investigated specimens from hot work steel in the heat treated state has been made using Rockwell method. The distribution of microhardness in the nitriding layer measured using Vickers micro-hardness testing method. The evaluation of the adhesion of coatings to the substrate was made using the scratch test. Wear resistance tests with the pin-on-disc method were carried out on the CSEM THT (High Temperature Tribometer) device at the room temperature and at the temperature of 500 degrees centigrade. The friction coefficient between the ball and disc was measured during the test. Findings: In case of the TiN(Ti,Al)N coating deposited onto the X37CrMoV5-1 nitrided hot work steel show a very good adhesion which has been revealed to the substrate material is comparison to the TiN/(Ti,Al)N coating deposited onto heat treated hot work steel. Taking into account the results of measurements, one can state that the lowest wear at certain conditions in both room and elevated temperatures show TiN(Ti,Al)N deposited onto plasma nitrided X37CrMo V5-1 hot work steel type. Practical implications: The investigation results will provide useful information to applying of the TiN/(Ti,Al)N PVD coating for the improvement of wear resistance of tools made from hot work steels. Originality/value: The paper contributes to better understanding the wear resistance at the elevated temperature to 500 degrees centigrade of the multilayer TiN/(Ti,Al)N PVD coating deposited onto heat treated and plasma nitrided hot work tool steel.

10

Wyładowanie jarzeniowe w urządzeniach do obróbek powierzchniowych metali

63%

Niedbała R.

|

2007

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tom Z. 5

11-20

PL

Zadawalające rezultaty uzyskiwane w technologiach z udziałem wyładowania jarzeniowego spychały na dalszy plan całościowe rozwiązania urządzeń i planowanie procesów energetycznych. W referacie przedstawiono cechy wyładowania jarzeniowego anormalnego w aspekcie procesów azotowania detali o różnorodnej geometrii. Podano dostrzeżone związki pomiędzy charakterystykami energetycznymi wyładowania jarzeniowego a stratami cieplnymi. Na podstawie zebranych doświadczeń określono wzajemne współdziałanie układów zasilających z odpowiednimi konstrukcjami pieców, które mogą przyczynić się do oszczędnego gospodarowanie energią elektryczną podczas długotrwałych procesów technologicznych.

EN

Satisfying results obtained in technologies using the glow discharge processes, played down the globar constructional solutions of installations and planning of processes from the point of view of rational use of energy. In the paper the features of abnormal glow discharge, applied to nitriding parts of various shapes, are presented. The observed relations between energy characteristics of glow discharge and heat losses were given. On the ground of experiments was determined the cooperation of supply units with different constructions of furnaces, that could make possible the saving of electric energy used at longlasting technological processes.

11

Efektywne wykorzystanie energii elektrycznej w piecach jarzeniowych

63%

Niedbała R.

|

2008

|

tom R. 84, nr 7

56-59

PL

Zadawalające rezultaty uzyskiwane w technologiach z udziałem wyładowania jarzeniowego spychały na dalszy plan całościowe rozwiązania urządzeń i planowanie procesów energetycznych. W referacie przedstawiono cechy wyładowania jarzeniowego anormalnego w aspekcie procesów azotowania detali o różnorodnej geometrii. Podano dostrzeżone związki pomiędzy charakterystykami energetycznymi wyładowania jarzeniowego a stratami cieplnymi. Na podstawie zebranych doświadczeń określono wzajemne współdziałanie układów zasilających z odpowiednimi konstrukcjami pieców, które mogą przyczynić się do oszczędnego gospodarowanie energią elektryczną podczas długotrwałych procesów technologicznych.

EN

Satisfying results obtained in technologies using the glow discharge processes, played down the globar constructional solutions of installations and planning of processes from the point of view of rational use of energy. In the paper the features of abnormal glow discharge, applied to nitriding parts of various shapes, are presented. The observed relations between energy characteristics of glow discharge and heat losses were given. On the ground of experiments was determined the cooperation of supply units with different constructions of furnaces, that could make possible the saving of electric energy used at longlasting technological processes.

12

Behaviour of nitrided layers subjected to influence of hydrogen

63%

Ćwiek J. , Baczyńska M.

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2010

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tom Vol. 43, nr 1

30-41

EN

Purpose: of this paper is evaluation of behaviour of plasma nitrided layers subjected to influence of internal and external hydrogen. Properties of nitrided layers like: hydrogen permeation and trapping, fracture mode, and plasticity were examined. Design/methodology/approach: Structural low-alloy steel was nitrided at glow discharge in the gas mixture of various N2, H2, and Ar content. Samples with nitrided layers were subjected to cathodic hydrogen charging in acid solution simulating the aged engine oil hydrogenating environment. The effect of the nitrided layers on the hydrogen transport and on the irreversible trapping was evaluated by the measurements of the hydrogen permeation rate and by the vacuum extraction, respectively. Surfaces with modified layers were examined with the use of a scanning electron microscope (SEM) before and after hydrogen permeation tests. Slow strain rate test (SSRT) on samples with and without nitrided layers was carried out in hydrogen generating environment. After SSRT fracture mode and plasticity of nitrided layers were examined with SEM. Findings: In the presence of the not defected compact nitride layer, no hydrogen permeation through the steel has been stated under the experimental conditions. Influence of hydrogen content in working atmosphere, i.e. internal hydrogen, was found. Absorbed hydrogen, i.e. external hydrogen, was accumulated within this layer. Research limitations/implications: There is no possibility to perform direct observations of exact mechanism of hydrogen-assisted cracking so far. Further research should be taken to reveal the exact mechanism of increased plasticity of nitrided layer with absorbed hydrogen. Practical implications: Plasma nitrided layers are effective barriers to hydrogen entry into structural steel utilised in aggressive environments, which is especially important in the case of possible hydrogen charging of exploited steel. Originality/value: Using the atmosphere of the higher nitrogen to hydrogen ratio at plasma assisted nitriding provides the formation of thin compact nitride zone, highly protective against corrosion and hydrogen degradation. Evidences of a likely increased plasticity of nitrided layers with absorbed hydrogen was observed.

13

Wpływ wodoru na warstwy azotowane na stali 34CrAlNi7-10

63%

Ćwiek J.

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2011

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tom nr 4-5

225-229

PL

W artykule przedstawiono wyniki badań wpływu warstwy azotowanej jarzeniowo na stali 34CrAlNi7-10 na jej podatność na niszczenie wodorowe. Badania przeprowadzono rozciągając próbki z małą prędkością w powietrzu i środowisku kwaśnym podczas polaryzacji katodowej. Badano przenikanie oraz absorpcję wodoru przez warstwę azotowaną - wykonano elektrochemiczne pomiary przenikania wodoru przez membranę oraz pomiary ekstrakcji próżniowej. Przełomy próbek po próbach rozciągania obserwowano przy użyciu skaningowego mikroskopu elektronowego w celu określenia wpływu wodoru na zmianę charakteru pękania. Warstwy azotowane stanowią barierę dla wnikania wodoru do stali, przez co zmniejsza się jej podatność na niszczenie wodorowe. Wodór jest głównie akumulowany w strefie azotków. Nawodorowanie warstwy azotowanej nie powoduje zwiększenia jej kruchości w próbie odkształcania z małą prędkością.

EN

Studies on the influence of nitrided layer on 34CrAlNi7-10 on the susceptibility of steel to hydrogen degradation has been presented in the paper. Investigations were carried out using the slow strain tensile rate test (SSRT) in air and in an acidic environment under cathodic polarization. Permeation and absorption of hydrogen in nitrided layer were evaluated - an electrochemical hydrogen permeation test through a membrane, and hydrogen vacuum extraction test were performed. The fractured surface of the specimens with modified layers were examined using a scanning electron microscope (SEM) in order to determine the influence of hydrogen on change in the fracture mode. Plasma nitrided layers, being effective barriers to hydrogen entry into steel, decrease the susceptibility of steel to hydrogen degradation. Hydrogen is mainly accumulated in a compound nitrides zone. There is no evidences for increase in the brittleness of nitrided layers with absorbed hydrogen.

14

Badania nieniszczące warstw azotowanych na stalach narzędziowych za pomocą przyrządów Wirotest

51%

Pachutko B. , Małdziński L.

|

2006

|

tom nr 2

40-46

PL

W pracy przedstawiono wyniki badań grubości strefy azotków żelaza e+y' i grubości warstwy azotowanej (składającej się ze strefy faz e+y' i strefy wydzieleniowej a) na stali WCL i matrycach z tej stali, metodą prądów wirowych. W badaniach zastosowano przyrząd Wirotest 301 z czujnikiem ekranowanym (częstotliwość 0,5 i 1 MHz) oraz przyrząd Wirotest 03 z czujnikiem nieekranowanym (częstotliwość 3,4 kHz). Próbki azotowano gazowo w temperaturze 540 °C w czasie od 4 do 40 h przy potencjale azotowym NP = 3,6 atm.[do 1] oraz w temperaturze 500 °C w czasie od 22 do 76 godz. przy Np = 14,2 atm. [do 1/2]. Matryce azotowano jonowo w zakresie temperatury 500 = 520 °C w ciągu 10 h. Wykazano, że możliwa jest stosunkowo dokładna ocena grubości strefy faz e+y' i warstwy azotowanej za pomocą układów pomiarowych Wirotest. Zależność zmian wskazań przyrządów wiroprądowych od grubości tych warstw miała charakter liniowy lub zbliżony do liniowego. W badaniach grubości warstw azotowanych na matrycach uzyskano dobrą korelację wskazań przyrządu Wirotest 03 dla matryc i próbek kontrolnych. Opisaną metodykę badań można wykorzystać do oceny jakości azotowanych wyrobów.

EN

Thickness of the e+y' nitride zone and the total thickness of the nitrided layer (including the e+y' and the abase precipitation zones) on hot-work WCL steel and on dies made of the same material, were measured using eddy current method. Two types of istruments were used, Wirotest 301 with a shielded sensor (frequency 0.5 and 1.0 MHz) and Wirotest 03 with an unshielded sensor (3.4 MHz). Specimens were gas nitrided for 4 - 40 hours at 5°C 40 °C nd nitriding potential of 3.6 atm-1/2 and for 22 - 76 hours at 500 and potential 14.2 atm-1/2. Forging dies of WCL were plasma nitrided at 500 = 520 for °C 10 hours. It has been demonstrated that the Wirotest devices allow a relatively precise estimation of e+y' zone and nitrided layer thickness. The relationship between instrument indications and layer thickness was linear or close to linear. In the investigations of nitrided layer thickness a good correlation was obtained between the Wirotest 03 indications for dies and control specimens. The described method can be used for quality control of nitrided parts.