Abstract:
Continuously cast products (12) are often provided with surface defects such as oscillation marks (17) and other non-homogeneous structures in the cast state thereof during production in a casting die (11) of a continuous casting plant (10). Defects which render a strip useless for superior applications also frequently occur on the strip surface during subsequent milling of the slab (12″) into a strip. The aim of the invention is to minimize said defects and provide the rolling mill with a slab (12″) having a desired preliminary profile and an improved near-surface structure. Said aim is achieved by arranging a reducing roll stand (30) in the area of the bending rolls or straightening driver rolls (24) within the continuous casting plant (10). Said reducing roll stand (30) allows the cast billet (12) to be deformed in a specific manner at an early point in time while still having a high temperature and providing a high energy yield after being completely hardened such that the depth of the existing oscillation marks (17) on the cast billet surface (16) is reduced, the finely crystalline edge layer (18) is enlarged as a result of the energy being released which is introduced into the reducing billet (12′) during said deformation process, and increased recrystallization occurs and the grains in the deformed edge zone (19) of the slab (12″) are refined during the subsequent thermal treatment in a holding furnace (40).
Abstract:
A continuous casting and hot rolling apparatus for the parallel production for a multiplicity of rolled shapes, wire and rod of circular, oval and polygonyl cross section in which a continuous caster or flow shaper produces initially a plurality of discreet strands which continuously are fed to a hot rolling line and then can be diverted, if desired to a universal rolling unit in which pairs of strands are rolled alternately in vertical and horizontal rolls. The unit may be driven by a common motor and can have drive shafts for the respective stands located at the vertices of an isosceles triangle.
Abstract:
An assembly for producing a finished shape for a rod after the last rolling stage of a multi stand steel mill. This apparatus provides an operation for correcting minor surface irregularities and shape distortion of the rod as it exits from the finishing roll stand. The apparatus consists of four rollers mounted in an assembly which resembles a roller entry guide except that the rollers are capable of producing changes in shape of a work product passing therethrough. The orientation of the roller axis is slowly and constantly changed to prevent wear distortion of the rollers which may result when the rollers are required to roll a malformed product from fixed roller axes. The rollers may be driven in some circumstances.
Abstract:
A pair of roll support shafts which are supported by bearings provided at both ends of the roll support shafts, wherein, between the bearings, toothed drums are mounted on the roll support shafts or the circumference of the roll support shafts is provided with toothings. Outside of the bearings, roll disks can be mounted on the ends of the roll support shafts, wherein one of the toothed drums meshes with a drive pinion mounted on a parallel drive shaft and the other toothed drum meshes with a loosely mounted intermediate pinion, wherein the drive and the intermediate pinion also mesh with each other. The roll support shafts are each supported in a free end of a single-armed tumbler lever which is swingable about the longitudinal axis of the drive pinion or the intermediate pinion, wherein the tumbler levers are supported relative to the roll stand by means of adjustable and securable rigid or elastic support members and the free ends are supported relative to each other through elastic members.
Abstract:
A cassette-type roll stand for a two-high roll pair, wherein the bearing chocks of the roll stand are guided in a cassette formed by two housing frames which can be moved into and out of the roll stand. The housing frames are constructed as upwardly open U-shaped frames having oppositely located side members, wherein the side members are provided with guides for the bearing chocks of the lower roll and wherein one of the side members has extension projections with pivot bearings for the sides of the bearings chocks of the upper roll facing the pivot bearings. The other sides of the bearing chocks facing away from the extension projections are connected through spring-elastic connecting rods to the corresponding sides of the bearing chocks of the lower roll. In addition, an adjusting device and support and measuring devices for the cassette-type roll stand are arranged in the support frame.
Abstract:
In a rolling mill wherein hot rolled rod is directed along a downwardly curved path into a vertical laying head which forms the rod into a series of rings, a method of and apparatus for propelling the rod through the laying head. The rod is passed between a pair of adjustable driven pinch rolls located in advance of the downwardly curved path. An initial closing force is exerted on the pinch rolls to establish an initial parting prior to entry of a rod front end therebetween. The initial parting is sized to produce at least some rod deformation while providing a driving relationship between the pinch rolls and the rod. The initial closing force is greater than the momentary surge in separating force accompanying impact of a rod front end with the pinch rolls. The initial parting is maintained until the rod front end has negotiated the downwardly curved path and has passed through the laying head, at which time the initial closing force is released. The pinch rolls can then either be opened completely to allow the rod to continue running freely therebetween, or the initial closing force can be replaced by a lower secondary closing force which allows the rod to push the pinch rolls apart to a secondary parting. The second parting continues the driving relationship between the pinch rolls and the rod, without any accompanying rod deformation.
Abstract:
A roll mill stand has a supporting frame which mounts two housings with at least three work rolls being arranged therebetween, the geometric center lines of the rolls being located in a single plane and set one with respect to another to form a pass. The work rolls are mounted each in a respective shell, the latter being hinged upon one of the housings by a pivot secured in the housing parallel to the work roll and connected to the other housing by a screw-down mechanism intended to adjust the radial gap between the work rolls. At least one of the shells is supported by the respective pivot connecting the shell to the housing, the gap between the work rolls being adjustable transversally with respect to the axis of rolling.