Efeito da retificação com diferentes grãos abrasivos aplicado no ferro fundido nodular austemperado atrelado a qualidade e custo industrial.
Carregando...
Arquivos
Data
2023-01-25
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O ferro fundido nodular austemperado tem tomado espaço nas aplicações industriais devido as boas propriedades de manufatura, tais como usinabilidade, capacidade de tratamento térmico, elevada resistência mecânica, bom escoamento em moldes e baixo custo de fabricação. Haja vista a facilidade de confeccionar peças com dimensões próximas as desejadas. No entanto, para alguns conjuntos mecânicos é indispensável a aplicação de processos de usinagem para a correção de superfícies, otimização de rugosidade e padronização dimensional conforme norma. O processo de usinagem de retificação onde há o uso de abrasivos, tem uma posição estratégica na cadeia produtiva para o alcance desses parâmetros onde são necessários altos índices de qualidade. Há uma crescente variedade de grãos abrasivos a serem aplicados, todavia, para a retificação do ferro fundido nodular austemperado, destaca-se o uso de grãos de nitreto de boro cúbico (CBN) com variações de friabilidade que possibilitam maior rendimento no processo. Dessa forma, vislumbrou-se a necessidade de somar estudos a sociedade científica sobre a retificação do ferro fundido com diferentes friabilidades nos grãos abrasivos de CBN, conteúdo ao qual ainda é pouco explorado cientificamente. Para o estudo com utilização de dois rebolos com friabilidades diferentes, aplicou-se lubrirefrigeração constante, variando a velocidade de avanço em 0,5; 1,0 e 1,5 mm/min onde foi analisado o comportamento de rugosidade média aritmética (Ra e Rz), desvio de circularidade, desgaste diametral do rebolo, energia específica, emissão acústica, microdureza, microscopia óptica e análise de custo. Logo, na maioria dos resultados obtidos, o rebolo que possui grão abrasivos com menor friabilidade se comportou de maneira melhor quando comparado com o rebolo de maior friabilidade, devido a estabilidade do grão e maior resistência mecânica a deformação plástica.
Austempered ductile iron has gained space in industrial applications due to its good manufacturing properties, such as machinability, heat treatment capacity, high mechanical strength, good flow in molds and low manufacturing cost. In view of the ease of making parts with dimensions close to the desired ones. However, for some mechanical assemblies, it is essential to apply machining processes for surface correction, roughness optimization and dimensional standardization according to the norm. The grinding machining process, where abrasives are used, has a strategic position in the production chain to reach those parameters where high quality levels are required. There ir as growing variety of abrasive grains to be applied, however, for the grinding os austempered nodular cast iron, the use of cubic boron nitride (CBN) grains with friability variations that allow greater yield in the process is highlighted. Thus, there was a need to add studies to the scientific society on the grinding of cast iron with different friability in CBN abrasive grains, a content that is still little explored scientifically. For the study using two grinding wheel whit different friability, constant cooling was applied, varying the advanced speed by 0,5; 1,0 and 1,5 mm/min where the behavior of arithmetic mean roughness (Ra and Rz), roundness deviation, diametral wear of the grinding wheel, specific energy, acoustic emission, microhardness and cost analysis was analyzed. Therefore, in most of the results obtained, the grinding wheel that has abrasive grains with lower friability behved better when compared to the grinding wheel with greater friability, due to the stability of the grain and greater mechanical resistance to plastic deformation.
Austempered ductile iron has gained space in industrial applications due to its good manufacturing properties, such as machinability, heat treatment capacity, high mechanical strength, good flow in molds and low manufacturing cost. In view of the ease of making parts with dimensions close to the desired ones. However, for some mechanical assemblies, it is essential to apply machining processes for surface correction, roughness optimization and dimensional standardization according to the norm. The grinding machining process, where abrasives are used, has a strategic position in the production chain to reach those parameters where high quality levels are required. There ir as growing variety of abrasive grains to be applied, however, for the grinding os austempered nodular cast iron, the use of cubic boron nitride (CBN) grains with friability variations that allow greater yield in the process is highlighted. Thus, there was a need to add studies to the scientific society on the grinding of cast iron with different friability in CBN abrasive grains, a content that is still little explored scientifically. For the study using two grinding wheel whit different friability, constant cooling was applied, varying the advanced speed by 0,5; 1,0 and 1,5 mm/min where the behavior of arithmetic mean roughness (Ra and Rz), roundness deviation, diametral wear of the grinding wheel, specific energy, acoustic emission, microhardness and cost analysis was analyzed. Therefore, in most of the results obtained, the grinding wheel that has abrasive grains with lower friability behved better when compared to the grinding wheel with greater friability, due to the stability of the grain and greater mechanical resistance to plastic deformation.
Descrição
Palavras-chave
Retificação, Friabilidade, Nitreto de Boro Cúbico (CBN), Ferro fundido nodular austemperado (ADI), Grinding process, Friability, Cubic boron nitride (CBN), Austempered ductile iron