Avaliação da tenacidade à fratura do aço inoxidável AISI 304 usando o ensaio de puncionamento esférico

Abstract

This work evaluated the fracture toughness of AISI 304 stainless steel in two directions using the Small Punch Test. For this purpose, the multiple side notched specimen technique and the methodologies of the Lacalle’s and Energy Release Rate methods was employed. The obtained results indicated that both methodologies are capable of detecting material anisotropy, showing higher toughness in the longitudinal direction. Additionally, these results are within the range of conventional fracture toughness values found in the literature. However, the Energy Release Rate method exhibited results with a mean dispersion greater than 32 %, indicating low repeatability and significant uncertainty values that compromise the quality and reliability of the results. On the other hand, the Lacalle’s method yielded promising JQ results with low dispersion of 492 kJ/m² in the longitudinal direction and 436 kJ/m² in the transversal direction. Furthermore, the results of Lacalle’s method were compared with results from other materials subjected to the same method to provide qualitative information for the fracture toughness of AISI 304 steel. In this comparison, AISI 304 exhibited the highest toughness value among the analyzed steels.