METHOD FOR PRODUCING OF ROLLED BARS FROM LOW CARBON STEEL FOR COLD BULK PRESSING OF COMPOUND-SHAPED FASTENING PARTS

• Main Authors: ZIBOROV A.V, KULAPOV A.N, VODOVOZOVA G.S, BOBYLEV M.V, MAJSTRENKO V.V, PESHEV A.D, LAMUKHIN A.M, ANTONOVA Z.A, ZAKIROV D.M, STEPANOV N.V, RONZHINA L.N, LUTSENKO A.N
• Format: Patent
• Language: English; Russian
• Published: 20.10.2004
• Edition: 7
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

FIELD: metallurgy. ^ SUBSTANCE: method involves melting steel in electric furnace; processing beyond furnace; pouring in casting molds while protecting metal flow; hot rolling of ingot for producing of blank, with following rolling thereof and controlled cooling and winding of rolled product into rolls; melting steel containing, wt%: carbon 0.17-0.25; manganese 0.30-0.65; silicon 0.01-0.17; sulfur 0.005-0.020; vanadium 0.005-0.07; niobium 0.005-0.02; calcium 0.001-0.010, with following ratio being met: 12/C-Mn/0.02>=27; 0.46>=6xV+8xNb>=0.22; Ca/S>=0.065. Steel microalloying with niobium inhibits steel recrystallization processes at rolling final temperature of 1,000-1,0500C. Hot rolling of bars is completed at temperature of 1,000-1,0500C, with following accelerated cooling to temperature of 750-8500C and rolling at deformation extent of at least 30% with following cooling in air to temperature of 3000C. ^ EFFECT: provision for producing of rolled bars with structure allowing adequate cold bulk pressing conditions to be created without additional spheroidizing annealing process and improved steel deformability characteristics. ^ 2 cl, 2 ex