Influence of Cryogenic Treatments on Microstructure and Mechanical Properties of AISI 420 Stainless Steel

G. PRIETO; J. PEREZ IPIÑA; W. TUCKART; B. ŠETINA BATIč

Posadas

Congreso; 13er Congreso Internacional en Ciencia y Tecnología de Metalurgia y Materiales 2013 SAM CONAMET; 2013

Asociación Argentina de Materiales

This study aimed to analyze the microstructural changes and the effect of cryogenic treatments on hardness and impact toughness on martensitic AISI 420 stainless steel. The analysis of the changes in the volume fraction and size of carbides was made using scanning electron microscopy (SEM-EDX). Hardness was evaluated with the Vickers technique and impact toughness by mean of Charpy V notch tests. Fracture surfaces were analyzed by scanning electron microscopy to evaluate the fracture micromechanisms. Cryogenically treated specimens developed a hardness increase in the order of 4,8% and an impact toughness improvement of 9,8% compared to those quenched and tempered. SEM analysis of fracture surfaces showed a combination of dimples and cleavage  facets in all specimens.