SOLUTE CR ATOM DISTRIBUTION AND FRACTURE-BEHAVIOR OF MANET STEEL

The effects of heat treatments at 700 degrees C on the toughness behav iour have been investigated in MANET steel by means of Charpy impact t ests and SEM observations with microanalysis. The ductile to brittle t ransition temperature, the upper shelf energy and the slope in the duc tile to brittle transition depend strongly on the time of heating as a consequence of the different fracture mechanisms evolving with the th ermal treatment. The transition, from fracture mainly conditioned by l ath boundaries to fracture depending mainly on processes at the FAG bo undaries, appears correlated with the specific characteristics of the distribution of the Cr atoms in solution.