METHOD OF MAKING ROLLED PIECE FOR COLD DRAWING FROM CORROSION-RESISTANT CHROME-NICKEL STEELS Russian patent published in 1995 - IPC

FIELD: rolled stock production. SUBSTANCE: method comprises steps of rolling a billet of corrosion-resistant chrome-nickel steel had been heated up to a temperature of rolling operation, in stands of rough group, intermediate group and final group of a continuous rolling mill in order to receive a rolled piece with predetermined dimensions and with a temperature of rolling termination, equal to (1100-1200) C; performing rolling in the final stand group 4 with a deformation degree 60-80% curing the rolled piece, had been made, over a predetermined time period (up to 15 s), then subjecting it to preliminary cooling in the multisection line 5 for rapid cooling with use of set beforehand quantity of sections with predetermined numbers up to temperature (550-650) C, coiling the rolled piece to coils to be cooled by spraying in coilers up to temperature 450 C; setting a minimum time interval for curing the rolled piece after rolling before preliminary cooling of it according to a relation , where T_r.t.-temperature of rolling process termination, C; σ_r.t.-a necessary yielding strength of the rolled piece after rolling, kg/mm²; σ_o -basic yielding strength of the rolled piece after quenching at standard mode, kg/mm². EFFECT: enhanced quality of rolled piece. 1 cl, 1 dwg, 1 tbl