Controlled Rolling and Cooling Process Optimization of Non-annealed 12Cr1MoV Wire Rod Products for Boiler Flat Steel

Abstract

In order to develop non-spheroidizing annealing 12Cr1MoV hot rolled wire rod ， based on deformation induced phase transition mechanism， the finishing rolling temperature of 830 ℃ and laying temperature of 800 ℃ were adopted. By inhibiting deformation austenite grain recovery and recrystallization process，increasing deformation energy storage， thereby promoting austenite decomposed into ferrite and pearlite. Meanwhile in stage controlled cooling was realized with adjusting the air-cooled roller speed， the quenching microstructures were completely eliminated because prolonging the holding time between 630 ℃ and 750 ℃. The test results are that the tensile strength of 12Cr1MoV hot-rolled wire rod was reduced from 576 MPa to 520 MPa， while reduction of area increasing from 66% to 74%.The elimination of quenched microstructure significantly optimizes the deformation ability of wire rod ，and also avoided holes in the cross-section center or draw break which caused by a small or minimal martensite microstructure are unable to cooperate with deformation . Plastic cracking has not occurred after batch use of multiple specifications by users.

Keywords

• boiler flat steel； 12cr1mov steel； deformation energy； deformation induced phase transition； martensite