Mechanical strength and fracture toughness of high chromium white cast irons

Abstract

High chromium white cast irons are cast products with hard microstructures composed of an important fraction of intergranular chromium carbides dispersed in a tempered martensite matrix. The heat treatment of these products consists of a high temperature austenisation followed by quenching and two temperings, required in order to increase their overall hardness and to completely eliminate residual austenite. The mechanical behaviour of a low and a high carbon high chromium cast iron was determined by means of tensile, 500°C compression and fracture toughness tests. Products with high hardness and hot compression strength along with good fracture toughness were obtained. Their corresponding failure micromechanisms were defined by means of the analysis of fracture surfaces in order to provide an interpretation of the obtained results.

Keywords:

• HIGH CHROMIUM WHITE CAST IRONS
• CARBIDES
• HEAT TREATMENT
• RESIDUAL AUSTENITE