Abstract: Disclosed herein is an apparatus and method for forming a product having an asymmetric cross-section using a ring rolling process. The method of forming a product having an asymmetric cross-section uses a ring rolling process that uses a ring rolling apparatus, the ring rolling apparatus comprising: a main roll pressing a circumferential outer surface of a blank, a pressure roll pressing a circumferential inner surface of the blank, and a pair of axial rolls pressing upper and lower surfaces of the blank, wherein a protrusion provided on the pressure roll comes into contact with a depressed portion formed on the circumferential inner surface of the blank, and as a width of the blank varies, the pressure roll moves in a vertical direction.

Abstract: Disclosed herein is an apparatus and method for forming a product having an asymmetric cross-section using a ring rolling process. The method of forming a product having an asymmetric cross-section uses a ring rolling process that uses a ring rolling apparatus, the ring rolling apparatus comprising: a main roll pressing a circumferential outer surface of a blank, a pressure roll pressing a circumferential inner surface of the blank, and a pair of axial rolls pressing upper and lower surfaces of the blank, wherein a protrusion provided on the pressure roll comes into contact with a depressed portion formed on the circumferential inner surface of the blank, and as a width of the blank varies, the pressure roll moves in a vertical direction.

Abstract: Disclosed herein is a method of manufacturing a door frame for a wind tower. The method includes a first step of forging a circular planar substance, thereby forming a through hole in a central portion of the substance, a second step of heating the substance that was processed in the first step, a third step of ring-rolling the heated substance around the through hole in an annular shape such that a circumstance of a center hole of the substance is equal to a length of a center line of the door frame, a fourth step of upset-forging the annular substance so that opposite sides of the substance are pressed to form linear sections, and a fifth step of fine-finishing the substance that was processed by the fourth step, thus completing the door frame.

Abstract: The present invention relates to an injection type plasma treatment apparatus. An object of the present invention is to provide an injection type plasma treatment apparatus capable of treating work pieces with a variety of areas, sizes and shapes without damages due to micro arc streamer by using a method of injecting plasma, which is generated through dielectric barrier discharge (DBD) under the normal pressure condition, toward the work pieces.