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Article
Publication date: 1 January 1976

P.L. Hurricks

The first part of this paper appeared in our November/December issue and dealt with fretting wear behaviour of mild steel from room temperature to 600°C in air. The general…

98

Abstract

The first part of this paper appeared in our November/December issue and dealt with fretting wear behaviour of mild steel from room temperature to 600°C in air. The general mechanism for fretting is discussed at all temperatures where normal oxidative processes become involved. The nature of fretting wear is also covered and the effects of temperature are described. In this part of the paper, the discussion is continued to include triboxidation, delamination theory, atmospheric environment, transition temperatures, activitation energy and other factors affecting the influence of temperature on fretting.

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Industrial Lubrication and Tribology, vol. 28 no. 1
Type: Research Article
ISSN: 0036-8792

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Publication date: 1 February 1973

F.H. Stott

Introduction Although investigation of a corrosion problem using only one or two techniques can give useful information, the most complete picture of the processes involved, and…

19

Abstract

Introduction Although investigation of a corrosion problem using only one or two techniques can give useful information, the most complete picture of the processes involved, and thus the best approach for a satisfactory solution of the problem, often only results from the use and interpretation of a combination of techniques. In this respect, the Corrosion Centre is fortunate in having a wide range of long‐established and modern facilities at its disposal, enabling reasonable investigations to be carried out on many different types of corrosion problems. These techniques are used primarily for research and teaching purposes, but many of them can be made available to industrial users. Table 1 gives an indication of some of the techniques to which the Centre has access and briefly mentions some of their possible applications in corrosion studies.

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Anti-Corrosion Methods and Materials, vol. 20 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 October 2004

A. Ul‐Hamid, H.M. Tawancy, A.I. Mohammed, S.S. Al‐Jaroudi and N.M. Abbas

The oxidation behaviour of a wrought Ni‐Mo‐Cr alloy was studied under thermal cyclic conditions in air at 800°C for exposure periods of up to 1,000 h. The morphologies…

885

Abstract

The oxidation behaviour of a wrought Ni‐Mo‐Cr alloy was studied under thermal cyclic conditions in air at 800°C for exposure periods of up to 1,000 h. The morphologies, microstructures and compositions of the oxide scales were characterized by scanning electron microscopy, energy dispersive X‐ray spectroscopy and X‐ray diffraction. Oxidation kinetics were determined by weight gain measurements. Results show that steady‐state oxidation was achieved within 1 h of exposure while partial scale spalling was observed after 400 h. The alloy grain boundaries intersecting the alloy surface showed preferential oxidation. They became depleted in Ni and enriched in Mo and Cr during transient oxidation. The scale initially formed at the surface was NiO which grew outwardly and laterally to cover the entire alloy. Upon continued oxidation, the scale developed into an outer NiO layer and an inner Cr2O3 layer while the presence of NiMoO4 was also observed within the scale.

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Anti-Corrosion Methods and Materials, vol. 51 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 8 February 2016

Sonia Patricia Brühl, Amado Cabo, Walter Tuckart and Germán Prieto

The purpose of this study is to select a proper surface treatment to enhance wear resistance of engine camshafts. The camshaft is a relevant part of a diesel engine which works…

387

Abstract

Purpose

The purpose of this study is to select a proper surface treatment to enhance wear resistance of engine camshafts. The camshaft is a relevant part of a diesel engine which works under torsion, fatigue and wear efforts. They are usually manufactured by casting, forging or machining from forged bar of low alloy steels, and in most cases, the machined surfaces are quenched and tempered by induction heating. After that, in many cases, to withstand the efforts imposed on the active surfaces and improve tribology and fatigue properties, the industry used for decades, thermochemical technologies such as salt bath or gaseous nitriding and nitrocarburizing processes.

Design/methodology/approach

This paper studied the effects of plasma nitriding and plasma nitrocarburizing, on the tribological behaviour of the steel SAE 1045HM3 proposed to produce camshafts. After the plasma treatments, the change in surface roughness was measured; the modified layers were studied by X-ray techniques and its thickness by optical microscopy. The diffusion zone was evaluated by Vickers microhardness determinations. Tribology tests were performed by pin-on-disc configuration using WC ball as a counterpart.

Findings

Results show that plasma nitrided samples present the best tribological behaviour compared with the nitrocarburized ones; also, the influence of the roughness produced by the thermochemical processes appears to be important.

Practical implications

Although both the plasma treatments have been applied for many years, and also reported separately in the scientific literature, there was no information comparing these two treatments for carbon steels, and also, there is not much about tribology in lubricated conditions of nitrided and nitrocarburized carbon steels. In fact, it is not proved that the porosity of the nitrocarburized layer is beneficial for wear resistance in lubricated conditions. In this paper, it was proved that at least in the tested conditions, it is not.

Originality/value

Gas or plasma nitrocarburizing is usually recommended for this kind of applications, although the modified layer is porous. This paper attempts to prove that nitriding could be better than nitrocarburizing, even with a thinner white layer.

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Industrial Lubrication and Tribology, vol. 68 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 September 2006

H. Singh, D. Puri, S. Prakash and M. Srinivas

To characterise the high temperature oxide scales for some plasma sprayed NiCrAlY coated Ni‐ and Fe‐based superalloys.

862

Abstract

Purpose

To characterise the high temperature oxide scales for some plasma sprayed NiCrAlY coated Ni‐ and Fe‐based superalloys.

Design/methodology/approach

Ni‐22Cr‐10Al‐1Y metallic coatings were deposited on two Ni‐based superalloys; Superni 601 and Superni 718 and one Fe‐based superalloy; Superfer 800H by the shrouded plasma spray process. Oxidation studies were conducted on uncoated as well as plasma spray coated superalloys in air at 900°C under cyclic conditions for 50 cycles. Each cycle consisted of 1 h heating followed by 20 min of cooling in air. The thermogravimetric technique was used to approximate the kinetics of oxidation. X‐ray diffraction, SEM/EDAX and EPMA techniques were used to analyse the oxide scales.

Findings

All of the coated, as well as the uncoated, superalloys followed an alnost‐parabolic rate of oxidation. The NiCrAlY coating was found to be successful in maintaining its continuous contact with the superalloy substrates in all the cases. The oxide scales formed on the exposed NiCrAlY coated superalloys were found to be intact and spallation‐free. The main phases analysed for the coated superalloys were oxides of nickel, chromium and aluminium and spinel of nickel and chromium, which are expected to be useful for developing oxidation resistance at high temperatures.

Practical implications

The coated superalloys showed remarkable cyclic oxidation resistance under simulated laboratory conditions. However, it is suggested that these coated superalloys also should be tested in actual industrial environments of boilers and gas turbines, etc. so as to obtain more practical and reliable oxidation data.

Originality/value

The knowledge of the reaction kinetics and the nature of the surface oxide scales formed during oxidation is important for evaluating the alloys for their use and degradation characteristics in high temperature applications such as steam boilers, furnace equipment, heat exchangers and piping in chemical industry, reformer, baffle plates/tubes in fertilizer plants, jet engines, pump bodies and parts.

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Anti-Corrosion Methods and Materials, vol. 53 no. 5
Type: Research Article
ISSN: 0003-5599

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Publication date: 1 March 1989

Mention golf and most people will think of Gleneagles. But, earlier this month, to over 100 visitors from 18 countries the name Gleneagles was associated with the Aerospace…

35

Abstract

Mention golf and most people will think of Gleneagles. But, earlier this month, to over 100 visitors from 18 countries the name Gleneagles was associated with the Aerospace Industry.

Details

Aircraft Engineering and Aerospace Technology, vol. 61 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 13 June 2016

Amir Motallebzadeh, Erdem Atar and Huseyin Cimenoglu

This paper aims to study microstructure and high temperature tribological performance of hypo-eutectic CoCrWC hardfacing alloy (Stellite 12) deposited on steel substrate by…

283

Abstract

Purpose

This paper aims to study microstructure and high temperature tribological performance of hypo-eutectic CoCrWC hardfacing alloy (Stellite 12) deposited on steel substrate by plasma-transferred arc (PTA) welding technique.

Design/methodology/approach

Microstructural characterization of the deposited coating was made using electron probe microanalysis, X-ray diffraction and microhardness tester. Dry sliding wear tests were carried out with a ball-on-disc type tribometer at room and elevated temperature. Worn surfaces of the samples were examined by the EDX equipped SEM and Raman spectroscopy.

Findings

Results revealed that at room temperature and 300°C plasticity dominated wear mechanism was operative. Under oxidation dominated wear conditions (400, 500, 600 and 700°C), testing temperature plays a crucial role on the characteristics of the oxide tribolayers formed on worn surfaces. Development of Cr2O3 in the tribolayer at 600 and 700°C was beneficial in increasing wear resistance of examined coating.

Originality/value

While the sliding wear performance of Stellite alloys at room temperature has been investigated in details, published studies on tribological behavior of Stellite alloys with varying temperature are scarce. Therefore, the present work was undertaken to study the wear mechanisms and the type of tribolayers formed during sliding wear of PTA welding deposited hypo-eutectic Stellite 12 coating with increasing temperature up to 700°C.

Details

Industrial Lubrication and Tribology, vol. 68 no. 4
Type: Research Article
ISSN: 0036-8792

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Available. Content available
Article
Publication date: 1 February 1998

422

Abstract

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Industrial Lubrication and Tribology, vol. 50 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 June 2004

Anwar Ul‐Hamid

A study was undertaken to investigate the isothermal oxidation behaviour of Ni‐Cr binary alloys with 10, 20 and 30 wt per cent Cr exposed in air for 50 h at 1,000°C. Analytical…

775

Abstract

A study was undertaken to investigate the isothermal oxidation behaviour of Ni‐Cr binary alloys with 10, 20 and 30 wt per cent Cr exposed in air for 50 h at 1,000°C. Analytical transmission electron microscopy along with light microscopy and X‐ray diffraction were used to characterise the oxide scale. It was observed that the scaling behaviour exhibited by the Ni‐Cr alloys changes from generally “non‐protective” to “protective” as their Cr content increases from 10 to 30 wt per cent. The Ni‐10Cr alloy formed a continuous network of NiO leading to scales of high thickness while Ni‐30Cr exhibited only α‐Cr2O3 at its surface. The Ni‐20Cr alloy exhibited all three oxide phases and an intermediate scaling behaviour.

Details

Anti-Corrosion Methods and Materials, vol. 51 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 12 June 2017

Suraj R. and Jithish K.S.

This paper aims to present a comparative study of the wear properties of ferrous welded materials like EN8, EN9 and mild steel (MS).

303

Abstract

Purpose

This paper aims to present a comparative study of the wear properties of ferrous welded materials like EN8, EN9 and mild steel (MS).

Design/methodology/approach

The material is cut into specific dimension after hardfacing and is studied for the wear properties of the material. The wear testing is done on a pin-on-disc apparatus. The microhardness of the material is studied using the Vickers microhardness measuring apparatus.

Findings

The wear properties of ferrous welded materials like EN8, EN9 and MS are studied. It is found the MS has the least wear when compared to EN8 and EN9. The microhardness of MS is higher than EN8 and EN9, thus making it more wear-resistant than EN8 and EN9. The coefficient of friction in the dry sliding condition is found to be constant throughout the experiment.

Research limitations/implications

Major restriction is the amount of time required for use-wear analysis and replication experiments that are necessary to produce reliable results. These limitations mean that the analysis of total assemblages with the intention of producing specific results, especially of worked materials, is not feasible.

Practical implications

Generally, the complexity and rigour of the analysis depend primarily on the engineering needs and secondarily on the wear situation. It has been the author’s experience that simple and basic wear analyses, conducted in the proper manner, are often adequate in many engineering situations. Integral and fundamental to the wear analysis approach is the treatment of wear and wear behaviour as a system property. As a consequence, wear analysis is not limited to the evaluation of the effects of materials on wear behaviour. Wear analysis often enables the identification of nonmaterial solutions or nonmaterial elements in a solution to wear problems. For example, changes in or recommendations for contact geometry, roughness, tolerance and so on are often the results of a wear analysis.

Originality/value

The value of the work lies in the utility of the results obtained to researchers and users of the EN8, EN9 and EN24 material for their components.

Details

World Journal of Engineering, vol. 14 no. 3
Type: Research Article
ISSN: 1708-5284

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