Avaliação da fissuração por fadiga em tubos durante transporte marítimo
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Data
2010-03-01
Autores
Godoy, João Mauricio
Cavalheiro, Benedito Carlos
Pereira, Marcelo dos Santos [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Soldagem (ABS)
Resumo
Tubos de aço são transportados diariamente em todo o mundo, por caminhão, trem ou navio. Conseqüentemente, danos de transporte, podem ocorrer com freqüência e regularidade. O tipo de dano particular selecionado para este estudo foi o de trinca por fadiga, o qual é considerado como um dos mais críticos. Neste trabalho foram estudados tubos de aço fabricados de acordo com os requisitos da norma API 5L [1]. Foram efetuadas caracterizações químicas, mecânicas e metalográficas de um tubo com diâmetro 609,6 mm e espessura 15,87 mm grau X-65. A simulação do transporte por navio de tubos de aço foi feita submetendo-se seções de tubo com comprimento igual a 0,1 metro, a ciclos de fadiga por meio de máquina servo-hidráulica. Foi possível concluir que em tubos soldados, a região adjacente ao cordão de solda é a mais crítica, e que quando o posicionamento do tubo na carga é efetuado de maneira que a solda fique apoiada sobre alguma superfície rígida, a ocorrência de trinca por fadiga torna-se possível principalmente se os procedimentos de manuseio, carregamento e transporte não forem executados da maneira como recomendada pelos fabricantes de tubos e pela norma API [2].
Steel pipes are daily transported all over the world by truck, train or ship. Consequently, shipping damages may occur frequent and regularly. The particular damage selected for this study was fatigue cracking, that is considered as the more critical one. In this job were studied steel pipes manufactured according to the requirements of the specification API 5L [1]. Chemical, mechanical and micrographic characterizations were made in a pipe size Ø 609.6 mm x 15.87 mm grade X-65. For the simulation of a ship transportation of steel pipes, pipe lengths sections of 0.1 meter were submitted to fatigue cycles from a servo-hydraulic machine. It was possible to conclude that in welded pipes, the weld region adjacent to the weld toe is the more critical and when the pipe positioning at the vessel result in to be the weld in contact with rigid surface, the occurrence of fatigue cracking is possible mainly if the handling, loading and transportation procedures were not executed as recommended by the pipe manufacturers and by the API specification.
Steel pipes are daily transported all over the world by truck, train or ship. Consequently, shipping damages may occur frequent and regularly. The particular damage selected for this study was fatigue cracking, that is considered as the more critical one. In this job were studied steel pipes manufactured according to the requirements of the specification API 5L [1]. Chemical, mechanical and micrographic characterizations were made in a pipe size Ø 609.6 mm x 15.87 mm grade X-65. For the simulation of a ship transportation of steel pipes, pipe lengths sections of 0.1 meter were submitted to fatigue cycles from a servo-hydraulic machine. It was possible to conclude that in welded pipes, the weld region adjacent to the weld toe is the more critical and when the pipe positioning at the vessel result in to be the weld in contact with rigid surface, the occurrence of fatigue cracking is possible mainly if the handling, loading and transportation procedures were not executed as recommended by the pipe manufacturers and by the API specification.
Descrição
Palavras-chave
tubo soldado, carregamento em navio, trinca por fadiga, Welded pipe, transportation, fatigue cracking
Como citar
Soldagem & Inspeção. Associação Brasileira de Soldagem, v. 15, n. 1, p. 02-10, 2010.