THE INFLUENCE OF HARDNESS OF POLYURETHANE ON ITS ABRASIVE WEAR RESISTANCE

Tribologia ◽  
2016 ◽  
Vol 268 (4) ◽  
pp. 29-39 ◽  
Author(s):  
Dymitr CAPANIDIS

This paper presents the experimental determination of the effect of hardness of the polyurethane (PUR) in a form of the elastomer foam used in various parts of machines or appliances subjected to intensive abrasive wear. Such elements, among others, are static and dynamic technical seals, bumpers, shock-absorbing parts in joints of machine components, and elements of transport equipment in mining or in aggregate and mineral processing [L. 1–3]. Intensive abrasive wear also concerns parts of agricultural and construction machines, road transport, and transport packaging, as well as protective coatings, housing or shields of various machines, and equipment elements [L. 4, 5]. An increase in the abrasive wear resistance of directly determines an increase in the durability and operational reliability of machines and equipment [L. 6]. The hardness of the elastomeric polyurethane influences its physicomechanical and tribological properties [L. 7]. So far, relatively few works have focused on research into the effect of various factors, including the hardness of PUR on the tribological properties of PUR. The aim of this study is to broaden knowledge on the impact of the polyurethane hardness on its resistance to abrasive wear.

2004 ◽  
Vol 120 ◽  
pp. 129-136
Author(s):  
M. Przyłęcka ◽  
W. Gęstwa ◽  
G. E. Totten

There are a variety of opinions regarding the influence of retained austenite and carbides on the properties exhibited by carbonitrided steels. In this paper, the development of a model marking relationship between phase composition, and properties of hardened carbonitrided steel has been presented. A summary of the impact of structure on properties is provided in Table 1. In the study reported here, the impact of thermal processing conditions on retained austenite and carbides was examined for carbonitrided and hardened 20 (C22), 20H (20Cr4), 15HN (17CrNi6-6) and 16HG (16MnCr5) steels. The models that are reported were experimentally validated. In particular, the results obtained for structure with respect to hardness and abrasive wear resistance were discussed for carbonitrided and hardened 20H (20Cr4) steel.


2019 ◽  
Vol 945 ◽  
pp. 574-578 ◽  
Author(s):  
L.S. Malinov ◽  
I.E. Malysheva ◽  
E.S. Klimov ◽  
V.V. Kukhar ◽  
E.Y. Balalayeva

The effect of quenching from 900°C (20 min exposure) and different tempering in the 250-650°C (for 1 hour) interval, as well as additionally preliminary carburization for 8 hours at 930°C, followed by a similar heat treatment on abrasive and shock-abrasive wear of low-carbon manganese (10-24%Mn) steels, phase composition and mechanical properties was studied. It was confirmed that an increase in the manganese reduces the abrasive wear resistance and increases the impact-abrasive wear resistance. The expediency of carburization of low-carbon manganese steels is shown in order to obtain the residual austenite in the structure which amount and stability must be optimized in relation to specific abrasive impact characterized by the dynamic ratio with taking into account the chemical composition.


2016 ◽  
Vol 61 (No. 2) ◽  
pp. 92-97
Author(s):  
P. Valášek ◽  
M. Brožek

For renovation of functional surfaces of machines and devices for agricultural production it is possible to use, in addition to conventionally used methods, polymers with fillers – composites. The presence of microparticles in the polymeric matrix improves substantially the abrasive wear resistance and hardness. This contribution describes tribological properties of epoxy resin filled with chips of ferrous metals – the change of volume losses increase in dependence on the pressure increase (load) having effect on the worn surface. From the carried out experiments the considerable decrease of filled resin losses is evident compared with the resin without filler. At the same time the exponential increase of volume losses with the increased load was quantified in the course of tribological tests.


Wear ◽  
2019 ◽  
Vol 440-441 ◽  
pp. 203098 ◽  
Author(s):  
Oskari Haiko ◽  
Kati Valtonen ◽  
Antti Kaijalainen ◽  
Sampo Uusikallio ◽  
Jaakko Hannula ◽  
...  

2021 ◽  
pp. 50-54
Author(s):  

Relationships are established between the parameters of the structure of heat-treated steels and their abrasive wear resistance. A computer program is developed for the choice of material and methods of thermal hardening in order to ensure the required wear resistance. Keywords: heat treatment, dislocation density, extreme temperature, lowalloy steel, computer program. [email protected]


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1818
Author(s):  
Zhang Pan ◽  
Xuanpu Dong ◽  
Huatang Cao ◽  
Qiwen Huang

To investigate the role of different distribution forms of Fe–Cr–C cladding layer in the impact abrasive wear performance of Hadfield steel, the over-lapped Fe–Cr–C cladding layer and dot-shaped Fe–Cr–C cladding layer were deposited, respectively, by plasma transferred arc (PTA) cladding on Hadfield steel. The microstructure, microhardness and impact abrasive wear performance of the two cladding layers under the impact of glass sand, granite and quartz sand were investigated. The results showed that both microstructures of the cladding layers were hypoeutectic Fe–Cr–C microstructures. The average microhardness of the over-lapped cladding layer and dot-shaped cladding layer was around 560 HV0.2 and 750 HV0.2, respectively. The over-lapped Fe–Cr–C cladding layer could only improve the impact abrasive wear resistance of the Hadfield steel under the wear condition of the glass sand. Meanwhile, the dot-shaped Fe–Cr–C cladding layer could improve the impact abrasive wear resistance of the Hadfield steel under all the three kinds of the abrasives because of the overall strengthening effect of its convex shape and the hypoeutectic FeCrC microstructure.


Tribologia ◽  
2019 ◽  
Vol 288 (6) ◽  
pp. 57-63
Author(s):  
Jerzy Napiórkowski ◽  
Krzysztof Ligier ◽  
Magdalena Lemecha ◽  
Damian Fabisiak

The basic method for protecting industrial products against the destructive impact of the environment is to protect them with paint coatings. One of the important characteristics of paint coatings is their resistance to abrasive wear. The study tested three coatings with different granulations obtained by the electrostatic spraying method and then polymerised. The tests were carried out in two ways. Some of them were conducted in accordance with the standards in place at the paint manufacturer’s laboratory, while the testing for abrasive wear resistance was conducted at a laboratory of the University of Warmia and Mazury in Olsztyn. The study involved measurements of thickness, gloss, scratching resistance, and wear using a rotational abrasion susceptibility tester and the ball-cratering method. Based on the obtained results, a different resistance to wear of particular coatings was found depending on the test stand. The study found the suitability of the ballcratering method for the assessment of wear resistance of thin paint coatings. The proposed methodology omits the problem of measuring very small changes in weight, while the obtained wear results are linked to other characteristics of the surface layer.


2011 ◽  
Vol 199-200 ◽  
pp. 167-172
Author(s):  
Jia Wang ◽  
Qing Zhong He ◽  
Yong Hu ◽  
Ming Chao Wang

The new low alloy martensitic wear resistant steel 25Si2MnNi3 and steel 53Si2MnNi3 are developed, which hardness are about HB450 and HB600 respectively, the impact abrasive wear resistance of new low alloy steel relative to high manganese steel ZGMn13 is investigated on MLD-10 type impact abrasive wear tester under the different impact energy, and the wear mechanism is analyzed. As a result, the new low alloy martensitic steel which impact toughness is well always obtains better impact abrasive wear resistance than that of steel ZGMn13 under different impact energy, and the primary wear mechanism gradually changes from micro-ploughing and micro-cutting to micro-fatigue and micro-cracking with impact energy increasing.


Author(s):  
C.P. Doğan ◽  
J.A. Hawk

It is well known that experimentally-determined values of wear resistance are not materials’ constants, but rather measured responses to a particular set of conditions imposed by a specific wear environment. Nonetheless, a material’s tribological performance is often estimated based on its bulk material properties. For applications requiring abrasive wear resistance, for example, ceramic materials are traditionally selected based on their hardness and fracture toughness, which are assumed to be proportional to the wear resistance. However, recent studies have indicated that for many commercially-important ceramic materials, subtle differences in the microstructure (not always reflected in measured values of bulk hardness and fracture toughness), can lead to large variations in the abrasive wear resistance.A number of microstructural variables can influence the tribological properties of a ceramic material: matrix grain size, matrix grain shape, the presence of intra-and inter-granular second phases, and the presence of transforming second phases (in zirconias and zirconia-toughened ceramics, for example).


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