RING ROLLING MILL AND MANUFACTURING METHOD OF RING ROLLING MATERIAL

Japanese Patent JP2016193454

A

PROBLEM TO BE SOLVED: To provide a ring rolling mill suitable for stable shape control on ring rolling and to provide a manufacturing method of ring rolling material.SOLUTION: A ring rolling mill includes a rotation number control unit which controls a rotation number of an axial roller. Therein, the rotation number control unit controls the rotation number of the axial roller while repeating a first step of measuring a diameter at every predetermined time interval Δt, a second step of performing comparison of a measurement value Lof the diameter at a time t to a measurement value Lof the diameter at a time t+Δt and a third step of setting a control rotation number on the basis of the comparison result of the second step. When the comparison result of the second step is L≥L, a new control rotation number is calculated and set based on Lon the third step and, when the comparison result of the second step is L