Abstract: Twin roll strip caster comprising parallel casting rolls one of which is mounted on moveable roll supports which allow it to move bodily toward and away from the other roll. A pair of roll biasing units comprising compression act on roll supports to bias the moving roll toward the other roll. Biasing units comprise compression springs acting on roll supports through thrust transmission structures and thrust reaction structures. The positions of thrust reaction structures are set by hydraulic cylinder units operable to vary the position of each reaction structure to replicate movements of the respective thrust transmission structure so as to maintain a constant compression of the biasing springs regardless of lateral movements of the roll supports.

Abstract: Start up method for initiating casting of metal strip in a twin roll caster comprising parallel casting rolls. A casting pool of molten metal is supported on the casting rolls and confined at the ends of the rolls by side closure plates and the rolls are rotated to deliver cast trip downwardly from the nip between them. One roll is continuously biased laterally toward the other roll either by spring biasing units or by hydraulic biasing units. On start up the gap between rolls is set so as to be less than the thickness of the strip to be cast and the rolls are rotated at such speed that on pouring of molten metal to initiate casting strip is produced to a thickness which is greater than the initial gap between the rolls thereby to cause the biased roll to move bodily away from the other roll to increase the gap between the rolls to accommodate the thickness of the cast strip. This allows initiation of casting without the need for introduction of a dummy bar between the rolls.

Abstract: Strip material is fed to a reduction rolling mill by a steering device in the form of a pinch roll stand comprising pinch rolls to which strip gripping forces are applied by hydraulic cylinder units located at the ends of the pinch rolls. A reduction mill is similarly provided with a pair of hydraulic cylinder units which are independently operable to vary the pressure applied by the reduction rolls across the strip. Sensors sense the position of the strip at a first location in advance of the pinch rolls and a second location in advance of the rolling mill. This output of sensors is fed to a controller which controls operation of both sets of hydraulic cylinder units to steer the strip.

Abstract: A thin steel strip is passed through a pinch roll stand comprising pinch rolls to a hot rolling mill comprising work rolls and backing rolls. In advance of rolling mill, the strip passes over support rolls. An anti-crimping guide roll located immediately in advance of the rolling mill is mounted on a pair of rocker structures so as to be rasiable from a lower inoperative position to lift the strip out of a straight line path so as to pass around the anti-crimping roll and to be wrapped about the upper work roll, that roll supports the strip and resists buckling of the strip and the generation of crimping defects.

Abstract: Twin roll caster produces cast steel strip that passes in a transit path through pinch roll stand and optional hot rolling mill and runout table to a coiling station which has a pair of switchable coilers. A strip shear located in advance of the coiling station is operable to sever strip into discrete lengths which can be diverted by setting deflectors to allow the severed lengths to pass across a runout table to a scrap bin. The strip may be thus severed and diverted to scrap on development of strip defects or malfunctioning of equipment without stopping continuous casting and the strip redirected to the coiling station when the problem is rectified.

Abstract: Twin roll casting of metal strip (20) by rotation of parallel casting rolls (16) supplied with molten metal through distributor (19a) and delivery nozzle (19b). X-ray scanner (44) continuously scans the thickness of strip (20) to produce a signal which is a continuous measure of thickness variation along the strip due to eccentricities of the casting rolls (16). This signal controls operation of roll drive motors (53) to impose a pattern of speed variation on the rolls so as to reduce the amplitude of the thickness variations.

Abstract: Twin roll caster for casting metal strip comprises pair of parallel casting rolls forming nip to receive molten metal from elongate metal delivery nozzle formed in two pieces supported in end to end relationship with a gap between them. A pair of casting pool confinement plates are thrust against the ends of rolls by thrusters mounted with the side plastes on carriages forming part of moveable structures which are connected to the outer rends of nozzle pieces by pins and which can be moved by operation of screw jacks. The outer ends of nozzle segments can be accurately set in position relative to side plates prior to a casting and during a casting operation screw jacks can be operated so as to move the nozzle segments inwardly to match inward advance of the side plates as they wear.

Abstract: Method of producing strip comprising continuously casting plain carbon steel into a strip of no more than 5 mm thickness and coiling the strip. The strip is subsequently uncoiled and cold rolled then annealed to produce a stress relieved microstructure therein. The cold rolling produces a cold reduction sufficient to increase the tensile strength of the strip to at least 680 MPa but is such that the total elongation to break off the strip after the annealing is in the range 8% to 12%. The cold rolling may produce a cold reduction of the strip thickness in the range 40% to 80%. The continuously cast strip may be optionally in-line hot rolled prior to coiling to produce an initial strip thickness in the range 40% to 60%.

Abstract: Twin roll caster for casting thin steel strip comprises chilled casting rolls 16 mounted on roll supports 104. One of the rolls is fixed and the other is moveable laterally and biased toward the other roll by biasing units 119 acting on the moveable roll supports 104. A casting pool of molten steel is supported on the rolls 16 and the rolls are rotated to produce a solidified steel strip delivered downwardly from the nip between the rolls. A substantially constant gap is maintained between rolls 16 such that unsolidifed molten metal passes through the nip between the solidified shells of the forming strip and solidifies below the nip. The biasing units 119 are effective to apply substantially constant and low biasing forces to the biased roll. The biasing forces may be between the same and slightly more than the force required to balance the hydrostatic pressure of the casting pool and to overcome the mechanical friction involved in moving the biased roll.

Abstract: Continuous strip casting device comprises a pair of parallel casting rolls onto which molten metal is supplied by metal supply means. Casting rolls are enclosed by a casting chamber into which hot strip is delivered downwardly from the casting rolls. Strip passes downwardly into a cooling chamber where it can either fall into a moveable scrap box at the bottom of chamber or be guided by operation of moveable apron through an exit door from chamber into a heat exchange chamber provided with heaters. A pair of seal rolls are moveable in a seal chamber to form a seal between chambers and are provided with respective gas inlets to admit oxidation inhibiting gas into those chambers. Scrap box is moveable into and out of the bottom of chamber via a scrap box exchange chamber fitted with an airtight door.

Abstract: A pinch roll assembly that may be used for feeding hot metal strip comprises a pair of parallel pinch rolls. At least one of the rolls comprises a copper or copper alloy tube providing the external peripheral roll surface and internal water cooling passages to cool the cylindrical tube by flowing water through the passages. The copper or copper alloy tube is fitted to a cylindrical arbor formed with end shafts for mounting the roll in journal bearings. Shaft is provided with a rotary drive coupling and shaft is fitted with a rotary water coupling for flow of cooling water to the water flow passages.

Abstract: Twin roll casting of metal strip (20) by rotation of parallel casting rolls (16) supplied with molten metal through distributor (19a) and delivery nozzle (19b). X-ray scanner (44) continuously scans the thickness of strip (20) to produce a signal which is a continuous measure of thickness variation along the strip due to eccentricities of the casting rolls (16). This signal controls operation of roll drive motors (53) to impose a pattern of speed variation on the rolls so as to reduce the amplitude of the thickness variations.