Na instrumentiranom Šarpi klatnu može se ukupna energija loma razdvojiti na energiju inicijacije i energiju rasta prsline. To je iskorišćeno u ovom radu za ispitivanje udarne žilavost E postupkom zavarenog spoja čelika, mikrolegiranog niobijumom, vanadijumom i titanom. Izmerena je tvrdoća spoja, i izvedena su makro- i mikrostrukturna ispitivanja. Merenjem poprečne deformacije epruveta posle loma, fraktografskim pregledom i određivanjem udela krtog loma na površini preloma dobijeni su dodatni podaci o mehanizmu loma. Poređenje svih praćenih parametara omogućava ocenu sklonosti materijala ka krtom lomu, otpornosti na nastanak i rast prsline i potencijalnih mesta nastanka loma.It is possible to divide total impact energy on instrumented Charpy pendulum into energies for crack initiation and growth. This is applied in this paper for impact toughness testing of the joint, welded by E procedure in the steel, microalloyed with niobium, vanadium and titanium. Hardness of the joint was measured, and macro- and microstructural analysis has been performed. By measuring of lateral extension of specimens after fracture, fractography and brittle fracture appearance on fracture surface additional data about fracture mechanisms are obtained. The comparison of all considered parameters enables assessment of material susceptibility to brittle fracture, crack initiation and growth resistance and potential sites of fracture occurrence
