Estudo e alterações de composição e processos para a otimização da distribuição de tamanho de carbonetos do aço M3:2

Abstract

The VIMAC3V steel, which is a variation of the High-Speed Steel M3:2 according to ASTM A600, belongs to the category of high molybdenum content High-Speed Steels (M class) and includes alloying elements such as chromium, vanadium, and tungsten. It stands out for its exceptional wear resistance combined with toughness and hot hardness, making it suitable for various industrial tools such as taps, reamers, knives, dies, and punches. However, due to the high number of precipitated carbides in the matrix, VIMAC3V steel exhibits high resistance to abrasive wear during the machining of the final tool, resulting in low grindability when compared to other steels in the same class. This limitation has the potential to negatively impact productivity and increase industrial costs. Thus, this study was divided into two parts. The first part involved the characterization of commercial steels from different suppliers. The objective of this phase was to correlate the microstructure with the best combinations of properties for the application of this material. The results obtained from the characterization of commercial steels showed finer and more homogeneously distributed carbides, as well as relevant changes in the chemical composition of the material. The second phase consisted of implementing changes in the manufacturing process of this material to obtain an optimized microstructure based on the results obtained in the first phase. The studies focused on chemical composition analysis, microstructure, carbide quantification, types of inclusions, and wear resistance. The main microstructural feature observed was the distribution of the present carbides which demonstrated a significant improvement in the distribution and size of carbides. Therefore, it was concluded that the applied changes were effective and provided insights to understand and propose improvements in the microstructure toward refined carbides.