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Minoração do empeno em chapas soldadas
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O presente trabalho foi desenvolvido no âmbito da indústria naval, com base na adoção dos
melhores métodos e estratégias para minoração da quantidade de desempenos em chapas causados por
influência da entrega térmica transmitida pelas soldaduras e por outras práticas de preparação menos
ajustadas, tais como sequências erradas de montagem e incumprimento das dimensões e geometria
das juntas de soldadura, que também contribuem para este tipo de defeito.
Cada desempeno requer meios humanos e materiais para a sua execução, o que se traduz em
custos e perdas de qualidade que podem ser minimizados ou até mesmo eliminados, se forem seguidas
as normas e os procedimentos recomendados. Também por questões estéticas, nomeadamente no
segmento dos navios de luxo, as imperfeições exteriores e visíveis no casco do navio deverão ser
reduzidas ao máximo.
Neste contexto, são inúmeras as matérias a considerar para executar um trabalho de forma
competente e profissional, com o fim de obter um produto de excelência e economicamente rentável.
Desde a fase de projeto que devem ser considerados e estudados diversos fatores, tais como a seleção
dos aços a aplicar, mediante as suas características mecânicas e metalúrgicas, as espessuras das
chapas e tipos de perfis, assim como os processos de corte e soldadura utilizados. Da mesma forma, é
de extrema importância respeitar as normas de construção que vão sendo atualizadas e melhoradas ao
longo do tempo, assim como o seguimento dos procedimentos de soldadura mais adequados para cada
união soldada, selecionando o processo mais adequado mediante o tipo de material e a espessura a
soldar, definindo a geometria das juntas de soldadura e o rigor da sua preparação, os parâmetros a
seguir e os tipos de consumíveis a utilizar.
Todos esses aspetos foram considerados para o desenvolvimento deste Relatório de
Atividades, tendo servido como referência a construção do navio da categoria Polar (World Seeker),
em construção nos estaleiros navais West-Sea.
Os resultados obtidos através de diversos ensaios permitiram concluir quais os processos mais
eficazes para minorar a entrega térmica, reduzindo significativamente a necessidade de execução de
trabalhos de desempeno, aumentando a produtividade e reduzindo os custos de produção.
The present work was developed within the scope of the naval industry, based on the adoption of the best methods and strategies to reduce the amount of distortions in plates caused by the influence of the heat input by the welds and by other less adjusted assembly practices, such as incorrect assembly sequences and non-compliance with the dimensions and geometry in the welding joints preparation, that also contribute to this type of defect. Each straightening requires human and material resources for its execution, which represents costs and quality losses that can be minimized or even eliminated, if the recommended standards and procedures are followed. Also, for aesthetic reasons, namely in the segment of luxury ships, the external and visible imperfections in the hull of the ship should be reduced to a minimum. In this context, there are countless matters to consider in order to perform a job competently and professionally in order to obtain a product of excellence and economically profitable. From the design stage, several factors must be considered and studied, such as the selection of steels to be applied, based on their mechanical and metallurgical characteristics, the thickness of the sheets and types of profiles, as well as the cutting and welding processes used. Likewise, it is extremely important to respect the construction standards that are being updated and improved over time, as well as following the most suitable welding procedures for each welded joint, selecting the most appropriate process according to the type of material and the thickness to be welded, defining the geometry of the welding joints and the rigor of their preparation, the parameters to be followed and the types of consumables to be used. All these aspects were considered for the development of this report, having served as a reference the construction of the ship of the Polar category (World Seeker), built in the West-Sea shipyards. The results obtained through several tests allowed us to conclude which are the most effective processes to reduce heat input, significantly reducing the need to perform straightening work, increasing productivity, and reducing production costs.
The present work was developed within the scope of the naval industry, based on the adoption of the best methods and strategies to reduce the amount of distortions in plates caused by the influence of the heat input by the welds and by other less adjusted assembly practices, such as incorrect assembly sequences and non-compliance with the dimensions and geometry in the welding joints preparation, that also contribute to this type of defect. Each straightening requires human and material resources for its execution, which represents costs and quality losses that can be minimized or even eliminated, if the recommended standards and procedures are followed. Also, for aesthetic reasons, namely in the segment of luxury ships, the external and visible imperfections in the hull of the ship should be reduced to a minimum. In this context, there are countless matters to consider in order to perform a job competently and professionally in order to obtain a product of excellence and economically profitable. From the design stage, several factors must be considered and studied, such as the selection of steels to be applied, based on their mechanical and metallurgical characteristics, the thickness of the sheets and types of profiles, as well as the cutting and welding processes used. Likewise, it is extremely important to respect the construction standards that are being updated and improved over time, as well as following the most suitable welding procedures for each welded joint, selecting the most appropriate process according to the type of material and the thickness to be welded, defining the geometry of the welding joints and the rigor of their preparation, the parameters to be followed and the types of consumables to be used. All these aspects were considered for the development of this report, having served as a reference the construction of the ship of the Polar category (World Seeker), built in the West-Sea shipyards. The results obtained through several tests allowed us to conclude which are the most effective processes to reduce heat input, significantly reducing the need to perform straightening work, increasing productivity, and reducing production costs.
Descrição
RELATÓRIO DE ACTIVIDADE PROFISSIONAL
PARA OBTENÇÃO DO GRAU DE MESTRE EM ENGENHARIA MECÂNICA
Palavras-chave
Deformação Entrega Térmica Soldadura Parâmetros Desempeno de chapas