Influence of the heat treatment of aging on the mechanical properties and microstructure a stainless steel duplex 2507

Stainless steel duplex SAF 2507 was submitted to a heat treatment of aging at 685 degrees C, for periods of time from 140-1680 minutes; with the aim to induce the precipitation of the secondary phases, in particular the R phase. In this way, have been studied the changes in microstructure and mechanical properties. The results obtained evidenced significant changes on the mechanical properties of duplex stainless steel SAF 2507, as a result of the application of the heat treatment of aging. The study of the mechanical strength and toughness, showed a marked reduction for the conditions treated isothermally, in reference to the original condition. In a similar way, the assessment of the microhardness of the main phases of steel, demonstrated the increase of the toughness for the treated conditions, except for the last condition of study due to a overheating produced in the material. It is assumed by the results of the mechanical tests, the presence of intermetallic R phase. Through the microanalysis by EDX, microstructure of the samples aged collated the presence of the above mentioned phase. In addition, verified that the material after been treated isothermally, weakens; this is an effect generated by the precipitation of R phase.