Characterization of fracture behavior of a Ti alloyed supermartensitic 12%Cr stainless steel using Charpy instrumented impact tests

In this work, the toughness of a Ti-alloyed supermartensitic stainless steel with 12%Cr was evaluated by instrumented Charpy impact tests at - 46 degrees C. The material was heat treated by quenching and tempering at 500 degrees C or 650 degrees C. The temper embrittlement phenomena was detected in the specimen tempered at 500 degrees C, while the specimens as quenched and quenched and tempered at 650 degrees C presented a ductile fracture with high impact energy values. The predominance of cleavage fracture instead of intergranular cracks suggests that the temper embrittlement was caused by fine and disperse precipitation observed in the specimen tempered at 500 degrees C. The dynamic initiation fracture toughness (J(Id)) was calculated from the force versus deflection curves using three different methods suggested in the literature to obtain the initiation energy.