Integritet cevovoda hidroelektrane

Abstract

Iskustvo iz eksploatacije cevovoda hidroelektrana ukazuje na moguće procurivanje posle stabilnog rasta prsline ili raspucavanje u slučaju krtog loma. Uvođenje zavarljivih čelika visoke čvrstoće za izradu cevovoda donosi značajne uštede, ali se zahteva otpornost prema prslinama, naročito prema krtom lomu, osnovnog metala, metala šava i zone uticaja toplote. Za cevovod hidroelektrane "Bajina Bašta" je korišćen zavarljiv čelik visoke čvrstoće (do 700 MPa nazivnog napona tečenja), pa je investitor tražio dokaze o njegovoj otpornosti prema prslinama i krtom lomu. Prikazani su rezultati ispitivanja modela cevovoda i zavarenih spojeva, kojima je dokazana zadovoljavajuća zavarljivost čelika sa metalom šava niže čvrstoće (andermečing) i otpornost prema prslinama i krtom lomu.

Experience from service of hydro electrical power plant indicates the possible leakage after stable crack growth or bursting in the case of brittle fracture. Introduction of wield able high strength steels for production of penstock brings important savings, but crack resistance especially to brittle fracture, of parent metal, weld metal and the heat-affected-zone is required. For the penstock of "Bajina Bašta" hydro electrical power plant weld able high strength steel is applied (up to 700 MPa nominal yield strength) and investor requested the proof for its resistance to cracks and brittle fracture. The results of testing of penstock model and welded joints are presented, which confirmed acceptable weld ability of under matched weld metal (under matched effect) and resistance to cracks and brittle fracture.