Recomendações para o controle da qualidade do processo de têmpera de ferramentas de grandes dimensões

• Ano de defesa: 2014
• Autor(a) principal: Logiudice, Renato
• Orientador(a): Librantz, Andre Felipe Henriques
• Banca de defesa: Farina, Paula Fernanda da Silva , Araújo, Sidnei Alves de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Nove de Julho
• Programa de Pós-Graduação: Programa de Pós-Graduação de Mestrado e Doutorado em Engenharia de Produção
• Departamento: Engenharia
• País: Brasil
• Palavras-chave em Português: aços ferramenta para trabalho a quente; tratamento térmico; controle da qualidade; dureza; tenacidade
• Palavras-chave em Inglês: tool steels; hot working; heat treatment; quality control; hardness; toughness
• Área do conhecimento CNPq: ENGENHARIAS::ENGENHARIA DE PRODUCAO
• Link de acesso: https://bibliotecatede.uninove.br/handle/tede/980

In manufacturing industries, in general, is the wide use of tools such as die and mold manufacturing of their products. These tools made from tool steels are assets with aggregate self worth and has a broad parcel on aspects of productivity and competitiveness of organizations. This work aims to study the importance of quality control procedures for the heat treatment used in the making of these tools. The study was experimental and adhered-to tool steels for hot work: The VH13® and new alloys developed in the last ten years, and VHSUPER® TENAX 300®. Characteristics such as hardness and tenacity are emphasized in this work as influential on the performance of the tools. As the hardness of steel usual control parameter, it was found that it is not enough to guarantee the performance of the tool. It is also necessary to study the toughness. The study was conducted in two stages: In the first, conducted in the laboratory, samples of steels were subjected to heat treatments of hardening and tempering under controlled time and temperature conditions. In the second step we constructed a suitably large tool which has been treated in an industrial condition. Measurements of hardness and impact tests were carried on samples drawn from the surface and core of the tool and also treated in the laboratory. The results verified the existence of low cooling rate of the tool subjected to heat treatment by processing. This led to a significant decrease in the toughness of the tool due to the formation of bainite and carbide precipitation at grain boundaries, the latter in greater proportion. Already hardness was little affected. As the value of the toughness of steel an important feature in preventing cracks or even catastrophic tool breakage, controlled processes of heat treatment of tools is of fundamental importance to their quality and that service only the value of the characteristic of hardness, as is usually done by the service providers, it is not enough to ensure the quality of heat treatment of tools.