The numerical simulation on process parameters of AISI4340 Steel Φ600 mm cast bloom to 300 mm x 300 mm square billet breakdown has been carried out by Deform-3D software. The effects of heating temperature

rolling speed

reduction ratio and two passes reduction on rolling bloom center deformation and material flow are studied

the equivalent stress and material deformation characteristics of the center during the deformation process are analyzed to get forming law of Φ600 mm round continuous casting bloom rolling into 300 mm square bloom. The results show that the heating temperature has little effect on die strain of the core at 1 070 ~ 1 140 °C

and the variation range is about 2.3%. When the rolling speed is 1.0 ~ 2. 0 m/s and the total reduction is fixed

it is better to weld the core defects at deformation of first big then small