REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

Significance of cracks in the integrity assessment WELDED JOINT OF steels for elevated temperature

MERI BURZIĆ

IC, Faculty of Mechanical Engineering, University, Belgrade, mburzic@mas.bg.ac.rs

Radica Prokić- Cvetković

Faculty of Mechanical Engineering, University, Belgrade, rprokic@mas.bg.ac.rs

olivera popović

Faculty of Mechanical Engineering, University, Belgrade, opopovic@mas.bg.ac.rs

uroš lukić

Faculty of Mechanical Engineering, University, Belgrade, ulukic@mas.bg.ac.rs

Abstract: For better understanding of the phenomenon of crack initiation and propagation in welded joints of A-387 Gr. 11 steel designed for high-temperature and high-pressure application, it is necessary to determine the effect of heterogeneity of microstructural and mechanical properties on fracture toughness and fatigue crack initiation and propagation. Based on the tests conducted with pre-cracked CT and Charpy size specimens, the effect of heterogeneity of microstructural and mechanical properties of welded joints on fracture toughness and fatigue-crack growth parameters was determined.

Keywords: Alloyed steel A-387 Gr. 11 Class 1, Welded joint, Fracture toughness, Paris law, Fatigue crack growth rate.