Cardoso, Rogério AntãoFaria, Geraldo Lúcio de2020-08-262020-08-262019CARDOSO, R. A.; FARIA, G. L. de. Characterization of austenite decomposition in steels with different chemical concepts and high potential to manufacture seamed pipes for oil and gas industry. Materials Research, São Carlos, v. 22, n. 5, 2019. Disponível em: <https://www.scielo.br/scielo.php?pid=S1516-14392019000500210&script=sci_arttext&tlng=en>. Acesso em: 10 mar. 2020.1516-1439http://www.repositorio.ufop.br/handle/123456789/12653This work presents the characterization of austenite decomposition kinetics in two steels during continuous cooling considering non-deformed austenite grains. Two different chemical concepts of steels were evaluated: low carbon - high manganese and a relatively new concept based on low carbon - low manganese - high niobium contents. Dilatometric experiments, microstructural characterization procedures and microhardness tests were carried out. Experimental and calculated CCT diagrams were plotted and the adapted JMAK model was applied aiming to predict the austenite decomposition kinetics. The low carbon - high manganese steel was the most sensitive to the applied cooling rates and, due to that, presented the higher grain refinement and hardness increasing after continuous cooling. These results highlight that the Mn content decreasing may promote a potential loss of grain refinement in procedures of continuous cooling where the structure recrystallization does not occur, as in some welding procedures or conventional heat treatments applied in the seamed pipe manufacturing process.en-USabertoNb and Mn contentsContinuous coolingArtigo publicado em periodicoThis is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (https://creativecommons.org/licenses/by/4.0/deed.en). Fonte: o próprio artigo.https://doi.org/10.1590/1980-5373-mr-2019-0378