STUDY OF THE TENDENCY TOWARDS DELAYED FAILURE OF HIGH-STRENGTH BOLT STEELS MICROALLOYED WITH VANADIUM AND NITROGEN

摘要

Results are presented for laboratory and industrial studies of the influence of microalloying steels with vanadium and nitrogen on static strength, resistance to brittle and delayed failure of bolt joints. Dissolution in austenite and precipitation during tempering of carbide and nitride phases, microstructure and hardenability of bolts, and the results of fractographic study of fractures are studied. Features of the effect of various factors on an increase in strength, cold resistance, and resistance to slow failure of bolt steels microalloyed with vanadium and nitrogen are discussed.