Effect of Hydrogen on the Wear Resistance of Steels upon Contact with Plasma Electrolytic Oxidation Layers Synthesized on Aluminum Alloys

Abstract

The different nature of the effect of hydrogen on the tribological behavior of two carbon steels (st. 45 and st. U8) upon their contact with super solid plasma electrolytic oxidation (PEO) layers synthesized on two light alloys (AMg-6 and D16T alloys as the analogists of the A 95556 UNS USA and AA2024 ANSI USA alloys correspondently) was investigated in the medium of mineral oil of the I-20 type. To compare the effect of hydrogenation on the tribological properties of the analyzed contact pairs, similar tests were also performed on the same mineral oil with clear water or an aqueous solution of glycerine added to its content. A spinel-type film (hercynite) was formed upon friction of two contacting surfaces—the iron-carbon steels and PEO layers synthesized on the AMg-6 alloy. This film was a reliable protection against wear of the surface subjected to the effect of hydrogen. When steels came into contact with the PEO layers synthesized on the D16T alloy, surface protection against wear was ensured by another mechanism. The phenomenon of selective metal transfer in the friction zone (from one to another friction surfaces) was revealed.

Tribological behavior of plasma electrolytic oxidation layers synthesized on AMg6 and D16 alloys in couples with cast iron SCh 21–40

“…a b It was found that tribo structuresoxide films with the general formula FeAl2O4 (Fig. 2) were synthesized on the surfaces of cast-iron counter body after tests with PEO layers [6][7][8]. On the surface of the iron cast counter body in a friction couple with a PEO layer on AMg-6, the thickness of the oxide layer is significantly larger and is 3-5 microns.…”

“…A part of this energy, produced in the contact area, goes to its accumulation in the system, as a result of which oxide films of the type FeAl2O4, are synthesized on the surfaces of the steel counter body, and the other on the radiation of heat into the environment. The thermal energy formed in the process of frictional interaction of metal contact couples is directed primarily to their destruction, and in the frictional interaction of the contact couples of ceramicsthe metal goes on to synthesize tribo structures on the metal surface of the oxide type [6,8]. After frictional interaction with the PEO layer synthesized on D16 alloy, glycerate films but nonoxide films form on the surface of cast iron samples, which contributes to the selective transfer [8].…”

Crack Growth Behavior of Additively Manufactured 316L Steel—Influence of Build Orientation and Heat Treatment

“…The specific layered structure of an additively manufactured element affects the high anisotropy of the material [ 4 , 5 ] which plays a significant role from a fatigue performance point of view. Additionally, some research papers discuss powders usage [ 6 ] or additional energy sources [ 7 ] in various applications to improve the fatigue life.…”

Technology to Increase Hydrocarbon Wear Resistance of Friction Units of Hydrogen Aggregates

“…It is shown that hydrogen leads to increasing the rate of polymer wear, for example, nitrile butadiene rubber, as an example of an elastomer plastic, and, therefore, can contribute to the wear of the sealing elements of oil pumping units. Some methods of improving hydrogen wear resistance are given in [4]. During the friction of two contacting surfaces, which were iron-carbon steels and polyethylene oxide (PEO) layers synthesized on the AMG-6 alloy, a spinel-type film (hercynite) was formed.…”