Soldabilidade do aço 300M com e sem metal de adição para utilização em envelopes motores de foguete

• Autor(a) principal: Reis, Renan Marques Rosa dos [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155422; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-05-02/000883008.pdf
• topic: Solda e soldagem; Aço de alta resistência; Motores de foguetes; Solder and soldering

In Brazil, the Aeronautics and Space Institute (IAE) is responsible for research and development of aerospace technologies and one of its braches is the research in launching vehicles, more known as rockets. One of the main parts of a rocket is its motor case, a cylindrical case that wraps the propeller, has structural role as well pressure vessel. Some IAE projects use the 300M ultrahigh strength steel from an electroslag remelting process to design rocket motor cases, as the VLS-I and VS-40 projects, the first one a satellite launcher and the last one a sounding vehicle. The motor cases are designed through automatic welding 300M sheets with thickness about 3.2 millimeters with metal rod addition using the keyhole method and then undergo a specific heat treatment cycle. This study aims to study the plasma welding of 300M sheets without the addition of metal rod and compare the results with the process used nowadays. Mechanical strength evaluation through tensile test, microstructural analysis and Vickers micro-hardness profile were made on both welding conditions to reach the study's goal. The results shows huge difference between samples that undergo the heat treatment cycle and those that do not. Moreover, shows that the addition of metal rod increases the tensile strength without jeopardize the elongation. The homogenization of micro-hardness values and microstructure shows the efficiency of the heat treatment cycle. There is no big differences between samples with and without the addition of metal rod among those that undergo the heat treatment cycle