Estudo do efeito do boro e das condições de trefilação na delaminação de aços perlíticos

• Ano de defesa: 2009
• Autor(a) principal: Luciano de Castro Reis
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia Metalúrgica e de Minas; Engenharia metalúrgica; Trefilação de arame; Engenharia de minas; Metalurgia de transformação
• Link de acesso: http://hdl.handle.net/1843/BUOS-8DNJKL

Delamination is a type of fracture that can occur in pearlitic steel wire when they are subjected to tension torsion. To better understand this phenomenon, in this study the effect of the addition of boron to steel and conditions of the drawing on delamination were observed. The steel wire was produced and drawing on industrial scale, thermal treated in laboratory and subjected to torsion tests. The presence of boron reduced the chance of delamination, probably by due to the reduction of nitrogen in solution, which hinders the effects of ageing. This beneficialeffect of boron is improved when associated with a reduction in drawing speed. The reduction of drawing speed reduces the wire temperature which could lead to ageing phenomena to develop. A third factor was studied here, the scheme of drawing passes with "skin pass" at theend, but this was not as effective as the effect of boron or drawing speed.One of the effects of delamination is the reduction of performance of wires in instrumented torsion tests with torque cells, which was confirmed here.