Discussion on Velocity Coordination between Roll Units of Tandem Skew Rolling Process

During rolling pipes with the tandem skew rolling process，the metal flow velocities in the deformation zone of the piercing section，and in the deformation zone of the rolling section are separately affected by the roll rotation rate of the piercer and that of the mandrel mill.Therefore，the piercing speed and the rolling speed have to be matched to each other.And for this purpose，the times as for deformation of the workpiece at different rolling stages are computed，based on which，the average velocity as needed at each stage is deduced，and then the proper velocity match is obtained.The data from the calculation are verified via testing.The result demonstrates that the calculated velocity match data have high accuracy and reliability.