Ductile to brittle transition of an A508 steel characterized by Charpy impact test: Part I: experimental results

摘要: This study is devoted to the ductile–brittle transition behavior of a French A508 Cl3 (16MND5) steel. Due its importance for safety assessment PWR vessels, full characterization this steel with Charpy V-notch test in range temperature was undertaken. The aim provide wide experimental database and microstructural observations supply, calibrate validate models used local approach methodology. Mechanical fracture properties have been investigated over temperatures strain-rates. Effects impact velocity on curve, ductile tearing notch rise are presented discussed. A detailed crack initiation growth specimens also carried out. From fractographic investigations microvoids nucleation around carbide second phase particles, plastic strain threshold determined material. steels undergo toughness temperature, due change mode from coalescence cleavage fracture. systematic investigation nature position triggering sites any brittle (DBT) has leads conclusion that manganese sulfide inclusions do not play an increasing role as recently mentioned other studies higher sulfur content. In companion paper [Tanguy et al., Engng. Fract. Mech., press], numerical simulation using fully coupled presented.