Estudo do comportamento ao desgaste e corrosÃo dos aÃos inoxidÃveis AISI 316L e AISI 420 depositados pelo processo de aspersÃo tÃrmica a arco elÃtrico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Mechanical components behavior in service, are extremely dependent on the surface quality, the contact between areas and the environment where they are applied. Particularly, corrosion and ware damage, directly and indirectly, mechanical components surface that result in rise production and maintenance cost due to no programmed equipments stops to repair or parts substitutions. In industrial countries, these costs represent approximately 4.2% of internal product. To prevent or eliminate corrosion and ware effects, surface treatments are applied in mechanical components surface to improve their wear and corrosion resistance. Metallic coat deposition processes have been showed efficient, in industrial application, to prevent damage on metallic component surfaces, exposed to aggressive environment. Protective coat application, using materials with superior quality relative to base component metal is a usual industrial practice, despite having coat quality control. The technique of thermal spraying offers the possibility to coat construction materials mechanics such as common steel to carbon with other metals and leagues, objectifying to also protect them against the corrosion and to the wear. Based on this context, the present work of this M.Sc. thesis has as objective to analyze and to compare the performance of the applied industrially metallic covering by thermal spraying processes. Its analyses coat based on the stainless steels AISI 316L, AISI 420 and mixture of these tows steels, and evaluates the corrosion and wear resistance of applied coats. Corrosion resistance, from AISI 316L, and wear resistance, from AISI 420, is expected from the applied coat properties. Heat treatment was applied on the AISI 316L + AISI 420 coat, and evaluated its effect on coat properties. The coats were applied by Thermal Spray Arc Process and it was analyzed the micro hardness of deposited materials and the corrosion and ware resistance of applied coats. With propose of wear resistance behavior, it was designing and manufactured a device based in pin on a disk test instrument, efficient on wear properties evaluation. Corrosion resistance test was made with electrochemical technique, in chlorine environment. Mechanical, micro structural and chemical of applied coats ware made with specifics normalized tests for each desired properties evaluation. Optical and Electric Scanning Microscopy ware used on the micro structure evaluation. X â Ray Difractometry was used on coat phase components identification. For all applied coat, the tests showed improvement on wear and corrosion resistance, improvement on surface micro hardness and cost porous in acceptable level close 6%. The thermal treatment applied improves all evaluated properties comparatively with no treated coat. From obtained results, the arc thermal spray process showed to be a satisfactory performance on stainless steels AISI 316L, AISI 420 and mixture of these tow steels coat application on low carbon steel surface

ASSUNTO(S)

corrosion stainless steel aspersÃo tÃrmica thermal spraying corrosÃo aÃo inoxidÃvel engenharia mecanica

ACESSO AO ARTIGO

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