As Atuais Fronteiras Tecnológicas Do Desenvolvimento De Chapas Grossas Para Sour Service

Abstract

Resumo Apesar do excesso de oferta mundial de petróleo e da crise brasileira, que reduziram a demanda de chapas grossas para a fabricação de tubos de grande diâmetro, o desenvolvimento técnico dos aços destinados a essa aplicação continuam evoluindo e tornando-se cada vez mais severos. O objetivo deste trabalho foi destacar três dos maiores desafios ainda a serem vencidos nesse campo e os mais recentes desenvolvimentos associados a eles. A Gerdau Ouro Branco, em seu esforço para se tornar um fornecedor preferencial e confiável dessa classe de chapas grossas, não só vem acompanhando com atenção os desdobramentos que vêm ocorrendo nessas áreas, bem como em outros aspectos relevantes a esse tema, e desenvolvendo seus próprios esforços para solucionar os problemas envolvidos. Palavras-chave:Fragilização por H 2 S; Fratura inversa; Pontos duros; Aço Microligado com Alto Nb. THE CURRENT TECHNOLOGICAL FRONTIERS OF THE DEVELOPMENT OF SOUR SERVICE HEAVY PLATES Abstract Despite the global oversupply of oil and the Brazilian crisis, which have reduced the demand for heavy plates used in the manufacture of large diameter pipes, the technical development of steel for this application continues to evolve and become increasingly severe. The objective of this work was to highlight three of the biggest challenges still to be overcome in this field and the most recent developments associated with them. Gerdau Ouro Branco, in its effort to become a preferred and reliable supplier of this class of heavy plates, has not only carefully monitored developments in these areas, as well as in other aspects relevant to this subject, and developing its own efforts to solve the problems involved.

Laminação Termo-Mecânica Visando a Obtenção De Um Aço Api 5l Grau X80 No Laminador De Chapas Grossas Da Gerdau - Efeitos Das Estratégias De Laminação

“…The continuous search for steels with high mechanical strength but even with lower levels of equivalent carbon, led to the creation of the Controlled Rolling strategy followed by Accelerated Cooling or TMCP (Thermo-mechanical Controlled Process), with the installation of processes for accelerated cooling in the plates, which further refine the grain size formed after controlled rolling, compensating for the impoverishment of the chemical composition. However, the high investment required to install this cooling system prevented widespread use of the concept [4]. Genarally, the API 5L X80 pipe steels produced in Brazil using the TMCP route have a microstructure with an acicular morphology with a predominance of bainite, having a low carbon content and microalloyed with niobium, vanadium and titanium [3].…”