Estudo do processo de envelhecimento em tubulações de aço carbono que operam sob temperaturas de até 500º C

• Ano de defesa: 2020
• Autor(a) principal: Fernanda Magalli Almeida Monteiro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ENG - DEPARTAMENTO DE ENGENHARIA METALÚRGICA; Programa de Pós-Graduação em Engenharia Metalúrgica, Materiais e de Minas; UFMG
• Palavras-chave em Português: Grafitização; Envelhecimento; Multi alinhamentos; EELS; FIB; Engenharia Metalúrgica; Metalurgia física; Grafita
• Link de acesso: http://hdl.handle.net/1843/47084

The aging process causes metallurgical modification that can affect the materials mechanical properties. An example of aging is graphitization which is characterized by the decomposition of cementite into graphite. The current study aims at the characterization of aging process, specially graphitization, in different samples. Moreover, it tries to study the damage mechanism and it can suggest improvements in inspection activities. Samples of carbon steel (DIN n 1.0305 St 35.8 e ASTM A106 grau B) aging in industry atmosphere were studied and electron microscopy and related techniques have been used to characterize the graphite particle. Different factors contribute to occurrence of graphitization, but the process of aging is not clear in the literature yet. In this study, samples showed different graphitization behaviors even in areas having the same chemical composition and under the same process conditions. The graphite analyzed showed typical crystalline planes and diffraction patterns. In addition, changes in the chemical bonds of carbon and magnetic domains were observed.