INVESTIGATION OF PECULIARITIES OF DEEP DEOXIDIZED STEEL INTERACTION WITH REFRACTORY LINING OF LADLE DURING THE MANUFACTURING OF LARGE FORGE INGOTS WITH MASS UP TO 415 TON

摘要

In the modern power engineering machinebuilding the high demands are made for the quality of forged semiproducts for producing of different parts. It is possible to guarantee their high quality only at conditions of metallurgical defects absence in initial ingots before forging. In result of fulfilled investigations of deep deoxidized steel quality for producing of large-size ingots, the evidence of secondary contamination of steel by exogenous nonmetallic inclusions were obtained. In order to determine the source of contamination, the chemical and phase composition of inclusions were investigated. It is established that they are formed in result of complex interaction in "slag - metal - refractory" system. The mechanism of system component interaction at three levels of ladle which corresponds to contact of refractory lining mostly with slag, metal or slag-metal was studied. With using of petrography analysis and scanning electron microscopy techniques the peculiarities of refractory destroying and metal contamination were shown.