Microestruturas e microdureza após nitretação a plasma de aço ferramenta AISI D2 com teor de cromo modificado para 8% para trabalho a frio

Abstract

It is known the great importance of the tools steels for the metal-mechanic industry and how essential these studies and researches developed towards the improvement of its own mechanic properties. The thermic treatments and superficial thermochemical treatments are broadly applied to these steels, because provides a significantly improvement of its hardness, wear resistance and cold deformation resistance. Particularly for cutting works, stamping, usage in dies and molds, the D steels family are very efficient related to the excessive wear existent in this applications. This project has as an objective, study the relations between different tempering temperatures and the plasma nitriding on the hardness of the modified AISI D2 with 8% Cr steel, which allows choosing the best combination of treatment temperatures and thermochemical treatment. Thus, it is possible to find improved results, in accordance whit the technical requirements and according to the desired application. The results found were compared among three groups of samples, which were tempered twice, tempered thrice and plasma nitride. Each group of samples that have been submitted to tempering was formed by three sub groups, they were tempered in three different temperatures. The temperature used during the plasma nitriding was the same of one of the tempering ones. It’s possible to find for the tempering and plasma nitriding groups, results based on the hardness and their corresponding microstructures, allowing identifying the conditions that define the best results for each one of the studied conditions.