Hot steel plate rolling mill system and rolling method
AssigneeHitachi, Ltd.
InventorsToshiyuki Kajiwara, Shigekazu Nagashima, Yasutsugu Yoshimura
Life of this patent
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Abstract
A mill including large-diameter work rolls which are directly driven is disposed in an upstream stage of a hot strip finish rolling mill train, and mills including small-diameter work rolls which are driven by back-up rolls or intermediate rolls are disposed in middle and downstream stages of the hot strip finish rolling mill train, so that a strip can be rolled with strong draft and at a low speed, whereby a small-scale production of hot strips on the order of million tons annual yield can be achieved with a compact structure of equipment.
Claims35
A hot rolling mill system comprising:
- a rough rolling mill, and
- a finish rolling mill disposed downstream of the rough rolling mill,
- said finish rolling mill including:
- at least one rolling mill stand with small work rolls of a diameter of not greater than 450 mm, said work rolls being indirectly driven by respective driven rolls engaging an outer circumference of the respective small work roll,
- at least one additional rolling mill stand disposed upstream of said at least one rolling mill stand, and
- a selectively operable strip loading end reducing device at the additional rolling mill stand which is operable to reduce a thickness of a leading end of hot material strip from the rough rolling mill to enable said work rolls of said at least one rolling mill stand to bite the thus reduced hot material strip leading end, said strip leading end reducing device being switchable after said leading end has been reduced in thickness to facilitate finish rolling utilizing paid at least one additional rolling mill stand.
A method of making a rolled material strip comprising the sequential steps of:
- supplying hot material strip to a rough rolling mill and rough rolling same therein, and
- finish rolling the hot material strip in a finish rolling mill disposed downstream of the rough rolling mill,
- wherein said finish rolling includes:
- rolling said hot material strip in a plurality of rolling mill stands with small work rolls of a diameter of not greater than 450 mm, said small work rolls being indirectly driven by responsive driven rolls engaging and outer circumference of the respective small work rolls,
- and reducing a thickness of a leading end portion of said hot material strip in at least one additional rolling mill stand disposed upstream of said plurality of rolling mill stands with small work rolls to enable said work rolls of a next adjacent rolling mill stand to bite the thus reduced hot material strip leading end portion, said reducing including operating said at least on additional rolling mill stand in a strip reducing mode, followed by operating said additional rolling mill stand in a rolling operation mode after said leading end portion has been reduced in thickness.
Dependencies are inferred from the claim text.