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Advisor(s)
Abstract(s)
A indústria metalomecânica nacional possui uma larga tradição no fabrico de
equipamentos de elevada qualidade nas mais diversas vertentes. Seja em moldes, colunas
de geradores de energia eólica, torres de telecomunicações, equipamento para a agropecuária,
básculas de camiões ou simplesmente em silos, a indústria metalomecânica
portuguesa é reconhecida internacionalmente pela sua competitividade e qualidade.
Sectores como o da maquinagem, estampagem e soldadura mantêm viva a economia
nacional, exportando produtos e serviços de engenharia que são largamente reconhecidos
pelas empresas estrangeiras, tanto na Europa como em África e na América.
O sector da construção soldada teve sempre uma forte tradição no nosso país, conhecendo
um novo impulso com o fabrico de estruturas metálicas para geradores de energia eólica
e torres de telecomunicações. Atualmente esta indústria mantém viva a sua atividade
devido a um forte ’know-how’ nesta matéria e a uma qualidade invejável. Apesar do forte
‘know-how’ já existente, esta indústria está constantemente a ser solicitada para novos
desafios, passando pela necessidade da aplicação de novos materiais os quais trazem
sempre requisitos específicos aos processos, necessitando ser estudados com pormenor.
Este estudo baseia-se na necessidade de uma empresa industrial portuguesa precisar de
realizar equipamentos em construção soldada com base em aço do tipo Cr-Mo, grau 91,
cuja soldadura é tradicionalmente bastante complicada. A realização dos adequados
tratamentos ao material, quer antes, quer depois da soldadura, são a garantia de que a
qualidade final do produto atinge os níveis exigidos pelos clientes.
Assim, o presente estudo, com uma forte componente experimental, permitiu determinar
com sucesso quais as melhores condições para o ciclo térmico na soldadura que podem
ser aplicadas a esta liga, para que os resultados obtidos possam exibir a qualidade
desejada.
The national metalwork industry has a long tradition in the manufacture of high-quality equipment for a large number of industrial or agricultural activities. Whether in moulds, columns of wind power generators, telecommunications towers, livestock equipment, trucks structures or just in large equipment for storage, the Portuguese metalwork industry is internationally recognised for its quality and competitiveness. Sectors such as machining, stamping and welding, keep alive the national economy, exporting engineering products and services that are widely recognised by foreign companies, both in Europe and in Africa or America. The welded construction industry always had a strong tradition in our country, knowing a new impetus with the manufacture of metal structures for wind power generators and telecommunication towers. Currently, this industry keeps alive its activity due to a strong know-how in this area and an enviable quality. Despite the strong know-how already existent, this industry is constantly being requested for new challenges, through the need of new materials application, which always bring specific requirements to processes, requiring to be studied in detail. This study is based on a Portuguese industrial company need to perform works in welded construction with Cr-Mo steel, grade 91, which weldability is traditionally quite complicated. Performing the appropriate material treatments, either before or after welding, are the guarantee that the final product quality reaches the level required by customers. Thus, the present study, with a strong experimental component, allowed determine successfully the best thermal treatment conditions that can be applied to this alloy, allowing get the best welding conditions in order to reach the desirable quality.
The national metalwork industry has a long tradition in the manufacture of high-quality equipment for a large number of industrial or agricultural activities. Whether in moulds, columns of wind power generators, telecommunications towers, livestock equipment, trucks structures or just in large equipment for storage, the Portuguese metalwork industry is internationally recognised for its quality and competitiveness. Sectors such as machining, stamping and welding, keep alive the national economy, exporting engineering products and services that are widely recognised by foreign companies, both in Europe and in Africa or America. The welded construction industry always had a strong tradition in our country, knowing a new impetus with the manufacture of metal structures for wind power generators and telecommunication towers. Currently, this industry keeps alive its activity due to a strong know-how in this area and an enviable quality. Despite the strong know-how already existent, this industry is constantly being requested for new challenges, through the need of new materials application, which always bring specific requirements to processes, requiring to be studied in detail. This study is based on a Portuguese industrial company need to perform works in welded construction with Cr-Mo steel, grade 91, which weldability is traditionally quite complicated. Performing the appropriate material treatments, either before or after welding, are the guarantee that the final product quality reaches the level required by customers. Thus, the present study, with a strong experimental component, allowed determine successfully the best thermal treatment conditions that can be applied to this alloy, allowing get the best welding conditions in order to reach the desirable quality.
Description
Keywords
Soldadura SA213 T91 SA335 P91 Grau 91 Microestrutura Fluência Tratamentos Térmicos Pré-aquecimento Pós-aquecimento Soldabilidade Welding Grade 91 Microstructure Creep Heat-treatments Pre- heat treatment Post heat-treatment Weldability