Efeito da microadição de titânio e nitrogênio sobre a microestrutura, comportamento mecânico e resistência ao desgaste de aços Hadfield

Abstract

The effect of titanium and nitrogen addition on Hadfield steels was investigated. For that, two grades were produced, with and without the addition of titanium and nitrogen. The samples were characterized before and after heat treatment and the mechanical properties were evaluated by tensile tests and Charpy impact tests. The wear resistance was evaluated on dry sand rubber wheel abrasive tests. The macro and microstructure characterization demonstrated that the precipitation of titanium carbonitrides resulted in a coarse microstructure, with coarse columnar grains coexisting with equiaxed ones. These samples presented lower mechanical properties in comparison with the samples without titanium and nitrogen, which presented a finer microstructure. On the other hand, the presence of hard Ti(C, N) precipitates in the microstructure improved the abrasive wear performance of the steel during dry sand rubber wheel abrasive tests.