Article Title

Laser thermohardening of friction couple "ring - sleeve of cylinder"

Journal: Journal of Transsib Railway Studies V.2(26), 2016
Journal thematic sections: Railway rolling stock
Pages: 61-70
Authors: V. I. Shastin
udk: 621.373.826
Article reference
Shastin V. I. , Kargapol'tsev S. K. Laser thermohardening of friction couple "ring - sleeve of cylinder" Izvestiia Transsiba – The Trans-Siberian Bulletin, 2016, no. 2(26), pp. 61 – 70.

Abstract

Article is devoted to actual questions of research of microstructure,physic-mechanical and tribological indicators blankets of friction couple "ring-sleeve of cylinder" under laser processing.Analysis of base defects of elements of cylinder-piston group of internal combustion engines,methods their reduction and rise of tribotechnical characteristics are conducted.Notes that different kinds of thermos and chemical thermal processing of working surface of link are most effective means of rise of wear resistance of couple "ring-sleeve of cylinder".Using of perspective technology of laser thermostrengthening is offered with this target.Offering technologies find greater application in automobile and technics of agricultural purpose. But purpose of ICE in aviation industry due to their specific exploitative and specific design features is limited.At the same time,they may have important practical meaning. Different variants of laser modification of surfaces of coupling in the context of CPG of aviation engine of ASH-62IR are offered and analyzed in article. Data of microstructural analysis of blanket,indicators of microhardness and wear resistance are adduced.Short description of tribotechnical laboratory-scale plant and methodic of conduct an experiment on base of comparative analysis of findings is given.Wherein tribotechnical indicators are compared with results of metallographical researches and physic-mechanical properties of modification layer,in particular with indicator of microhardness. Conduct of tribological researches determines that rise of indicator of wear resistance of friction couple "ring-sleeve of cylinder" observed at all researching regimes of laser effect with acconting of identified border conditions of processing for both elements of coupling.Maximum value of wear resistance is observed at laser thermostrengthening of both surfaces of couple on critical levels of density of laser energy.These levels do not case of appearance of microcracks in blanket.Wherein wearing qualities of modification surface of cylinder sleeve may increase by 4,5 - 5 times and wearing qualities of piston rings more than 3 times. Theoretical bases of mechanism of wear of thermos thermostrengthening surfaces which illustrate kinetics of increase their wear resistance in result of formation of microstructure of special blanket with increased bearing capacity,microhardness and improved conditions of wear of modification layer.Experimentally validated that the greatest wear resistance is observed in the friction elements at their mutual modifying their surfaces.