Desenvolvimento de uma camada nitretada em aço inoxidável martensítico para aplicação em anéis de pistão, quando utilizada em motores ciclo otto bi-combustíveis (motores flex-fuel)

dc.contributor.advisorVatavuk, Janpt_BR
dc.contributor.advisor1Latteshttp://lattes.cnpq.br/2607688973456560por
dc.contributor.authorNocera, Eduardopt_BR
dc.creator.Latteshttp://lattes.cnpq.br/8377385976766682por
dc.date.accessioned2016-03-15T19:36:39Z
dc.date.accessioned2020-05-28T18:07:26Z
dc.date.available2013-11-18pt_BR
dc.date.available2020-05-28T18:07:26Z
dc.date.issued2013-09-19pt_BR
dc.description.abstractPiston rings are metal parts which, when installed on the pistons in the cylinders of the engine, become circular with variable pressure and self-expansive, providing a movable seal between the combustion chamber and the crankcase. These components are subjected to intense functional demand, being asked to submit a low wear rate and maintain their structural and functional integrity under high temperatures and pressures. Due to these requirements, the technique is known of providing up-to-face contact with coatings or surface treatments to improve wear. Currently the majority of applications in the compression rings are martensitic stainless steels. These rings have their tribological properties improved by gas nitriding treatment which gives the steel surface intermediate properties between metallic and ceramic materials with high resistance to adhesive wear, as well as to wear by abrasion. This technology has been applied since the 90s with great success and high market penetration. With demand growing for reducing emissions was introduced in the market the Otto cycle engines with bifuel, better known as Flex engines. The principle of operation of these engines is the use of gasoline and ethanol at any mixing. The compression ratio of the piston is optimized for gasoline and not optimized for ethanol, since the latter does not have limitations to the phenomenon of detonation and this fact makes it occurs more Ethanol injection into the combustion chamber providing an improper fuel does not wash burnt in the cylinder wall. The result was the creation of a different tribological system in the area of operation of the rings where the nitrided layer began to suffer a detachment. This study aimed to find a solution for this detachment, where the nitride layer was changed. The modification consisted in decreasing the precipitation of carbides in the grain boundaries through migration carbon more to the core of the ring making it more robust to cracks and less susceptible to hydrogen embrittlement. Was created two nitriding stages, one richer in nitrogen which provides the wear resistance required for applying and the second stage causes the carbon to become more concentrated in the core hindering the generation of cracks and, consequently, the detachment. There was a decrease in the hardness of the nitrided layer without deteriorating the wear resistance, creating a unique solution and extending the life of this technology.eng
dc.description.sponsorshipMAHLEpt_BR
dc.formatapplication/pdfpor
dc.identifier.citationNOCERA, Eduardo. Desenvolvimento de uma camada nitretada em aço inoxidável martensítico para aplicação em anéis de pistão, quando utilizada em motores ciclo otto bi-combustíveis (motores flex-fuel). 2013. 83 f. Dissertação (Mestrado em Engenharia de Materiais) - Universidade Presbiteriana Mackenzie, São Paulo, 2013.por
dc.identifier.urihttp://dspace.mackenzie.br/handle/10899/24167
dc.languageporpor
dc.publisherUniversidade Presbiteriana Mackenziepor
dc.rightsAcesso Abertopor
dc.subjectnitretaçãopor
dc.subjecttrincaspor
dc.subjectanéis de pistãopor
dc.subjectmotores flexpor
dc.subjectnitridingeng
dc.subjectcrackseng
dc.subjectpiston ringseng
dc.subjectflex engineseng
dc.subjectdetachmenteng
dc.subject.cnpqCNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICApor
dc.thumbnail.urlhttp://tede.mackenzie.br/jspui/retrieve/3597/Eduardo%20Nocera.pdf.jpg*
dc.titleDesenvolvimento de uma camada nitretada em aço inoxidável martensítico para aplicação em anéis de pistão, quando utilizada em motores ciclo otto bi-combustíveis (motores flex-fuel)por
dc.typeDissertaçãopor
local.contributor.board1Couto, Antonio Augustopt_BR
local.contributor.board1Latteshttp://lattes.cnpq.br/2893737202813850por
local.contributor.board2Andrade, Arnaldo Homobono Paes dept_BR
local.contributor.board2Latteshttp://lattes.cnpq.br/1605291530127961por
local.publisher.countryBRpor
local.publisher.departmentEngenharia de Materiaispor
local.publisher.initialsUPMpor
local.publisher.programEngenharia de Materiaispor
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