Efecto del H2SO4 1.0 N en la propagacion de la grieta por fatiga en los aceros inoxidables del tipo austenitico y martensitico

Abstract

In this paper the effect of H2SO4 solution on the fatigue crack propagation speed of the austenitic stainless steels (AISI 304) and martensitic stainless steels (AISI 420) were studied. The test were carried out using a compact sample type to a value of R and DP constant in air and in H2SO4 1.0 N solution. The results show that the sulfuric acid solution modifies lightly DK values for crack initiation in both materials, in a more significant way for the martensitic stainless steel than for the austenitic one. On the other hand, it is observed that the corrosive environment produces an increment on the crack propagation speed greater in the AISI 420 steel than the AISI 304 steel. The studies of the fracture surface at the scanner electronic microscope (SEM) show that the corrosive environment modifies sensitivity the striation mechanism of crack propagation at the austenitic structure, and it produces a bigger disruption at the martensitic structure.