DETERMINATION OF COLD CRACKING IN HSLA STEEL WELDS

Podana je problematika varivosti modernih konstrukcijskih jekel z ozirom na fenomene, ki pri varjenju nastopajo. Posebna pozornost je namenjena razpokljivosti v hladnem, vplivu vodika, vrsti varivostnih preizkusov na hladno razpokljivost ter njenem preprečevanju. Na osnovi praktične izvedbe Y–preizkusa je določena temperatura predgrevanja visokotrdnostnega jekla MICRAL 690 debeline 40 mm, pri kateri ne bo prišlo do pojava razpok v hladnem zvarnem spoju. Ugotovljeno je, da lahko z izračuni približno ocenimo temperaturo predgrevanja jekla. Zaradi navedenega je potrebno realno temperaturo predgrevanja jekla določiti z Y–preizkusom.The problems of weldability of modern high strenght steels in regard to the phenomenas that appeared during welding is presented. Special attention is intended to cold cracking, influence of hydogen, type of cold cracking welding tests and its prevention. On the base of experimental Y-test execution the preheating temperature of high strength steel MICRAL 690, thickness of 40mm is determined, where the cold cracking of welded joint is not appeared. The steel preheating temperature can be approximately estimated by calculations, thus the determination of experimental steel preheating temperature by Y-test is necessary