PRODUCTION OF DIFFERENTIAL THICKNESS PLATE

PURPOSE:To produce simultaneously two sheets of stepped plates by superposing two sheets of steel slabs having the same shape via a release material and welding the circumferential edge thereof then subjecting the superposed slabs to rolling including stepped rolling at the end of the rolling stage and finally separating the rolled slab to two sheets at the part of the release material. CONSTITUTION:Two sheets of steel slabs 4A, 4B having the same shape are superposed via a release agent 5 such as sodium aluginate and the circumferential edge thereof is fully circumferentially or partially welded. The welded slab is rolled with a rolling mill having work rolls above and below and the rolling is completed by providing a step to the slab at the end of the rolling stage. The two rolled members 4A, 4B are then separated to two sheets in the part of the material 5 and two sheets of the stepped plates 4A', 5B' having excellent flatness of the flat surface are simultaneously produced.