Microestrutura do metal de solda GTAW reforçado com carbonetos de titânio, parcialmente refundido por laser Nd:YAG pulsado
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Data
2017-07-28
Autores
Pontin, Gabriel Inácio [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O desgaste abrasivo é uma das causas de falhas em equipamentos e responsável por prejuízos nos processos industriais. Uma técnica capaz de minimizar os efeitos deste fenômeno é a aplicação de revestimentos duros nas superfícies críticas. Recentemente foram desenvolvidos revestimentos contendo carbonetos de titânio formados pela fusão de misturas contendo cavacos das ligas ASTM F67 e ASTM F136 sobre peças de aço-carbono ASTM A-36. Após a aplicação do processo de soldagem GTAW obteve-se significativa fração volumétrica de TiC grosseiro com elevada dureza. No presente trabalho foi investigada a refusão dessas soldas pelo processo de soldagem a Laser Nd:YAG pulsado. A microestrutura das amostras foi analisada por difração de raios-X (DRX), microscopia eletrônica de varredura (MEV) e microdureza Vickers. A caracterização microestrutural mostrou que houve refinamento dos carbonetos de titânio (TiC) na matriz ferrítica refundida com o Laser, cujo principal efeito foi um endurecimento do metal de solda. A caracterização mecânica demonstrou um aumento na microdureza da superfície do material. Este comportamento favorece o uso da refusão a Laser para a melhoria da qualidade das superfícies que demandam maior resistência ao desgaste abrasivo.
The abrasive wear is one of the causes of failures in equipment and responsible for damages in industrial processes. A technique capable of minimizing the effects of this phenomenon is the application of hard coatings on critical surfaces. Recently, coatings containing titanium carbides produced by melting mixtures containing ASTM F67 and ASTM F136 chip blends on ASTM A-36 carbon steel parts have been developed. After an application of the GTAW get process, an important volumetric fraction of coarse TiC with high hardness was obtained. In the present work the remelts is investigated for welds by the pulsed Nd: YAG Laser process. A microstructure of the samples was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Vickers microhardness. The microstructural characterization showed that there was a refinement of the titanium carbides (TiC) in the ferritic matrix remelt with the Laser, whose main effect was a hardening of the weld metal. The mechanical characterization showed an increase in the microhardness of the material surface. This behavior favors the use of laser cladding to improve the quality of surfaces that require high abrasive wear resistance.
The abrasive wear is one of the causes of failures in equipment and responsible for damages in industrial processes. A technique capable of minimizing the effects of this phenomenon is the application of hard coatings on critical surfaces. Recently, coatings containing titanium carbides produced by melting mixtures containing ASTM F67 and ASTM F136 chip blends on ASTM A-36 carbon steel parts have been developed. After an application of the GTAW get process, an important volumetric fraction of coarse TiC with high hardness was obtained. In the present work the remelts is investigated for welds by the pulsed Nd: YAG Laser process. A microstructure of the samples was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Vickers microhardness. The microstructural characterization showed that there was a refinement of the titanium carbides (TiC) in the ferritic matrix remelt with the Laser, whose main effect was a hardening of the weld metal. The mechanical characterization showed an increase in the microhardness of the material surface. This behavior favors the use of laser cladding to improve the quality of surfaces that require high abrasive wear resistance.
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Palavras-chave
Refusão a laser, Revestimento duro, Microestrutura, Ligas de titânio, Carbonetos de titânio, Desgaste abrasivo, Laser cladding, Hard coating, Microstructure, Titanium alloys, Titanium carbides, Abrasive wear