Because if the surface temperature of the roll is not controlled, the temperature in the rolling deformation zone will be out of control, and the real temperature-controlled rolling cannot be realized.
(3) Cooling of the roll core and roll chocks to protect
mechanical equipment; from a mechanical point of view, when the roll surface is artificially heated, due to the existence of heat conduction, the roll core, roll neck, and bearings in contact with it Both the bearing seat and the bearing seat will inevitably follow the temperature rise until it exceeds the allowable range of the
machine: after exceeding 80°C, the lubricating
grease in the bearing seat will liquefy and fail; the roll crown formed after the
thermal expansion of the roll reaches a certain level will affect the thickness accuracy of the rolled piece , the bearing seat may be stuck in the
rolling mill archway after being heated and expanded, resulting in failure of the hydraulic AGC, etc.
The disadvantages of this method are: low energy
utilization rate; continuous
temperature control of the rolls during the rolling process cannot be guaranteed; low efficiency, rolling must be stopped every once in a while to reheat the roll surface; it is difficult to uniformly control Temperature distribution in the width direction of the roll surface
In addition, due to the low
ignition point of materials such as
magnesium alloys, this
combustion heating method has certain dangers in practical industrial applications.
Another simple method is to roll several other high-temperature metal materials first, heat the roller table and the surface of the rollers, and then carry out rolling.
system, unable to meet the requirements of refined
temperature control production
The above two roll heating methods cannot realize precise control of the roll temperature, so neither is temperature-controlled rolling in the true sense.
[0011]
Chinese patent 200510086721.X discloses a roll core heating device for warm rolling of
magnesium alloy strips. This patent proposes a method of heating the roll from the core of the roll from the inside to the outside. Although the roll heating function is realized, there are several problems. Insufficient points: slow temperature rise, inaccurate
temperature control, no consideration of the
temperature gradient in the belt width direction (roll length direction), no consideration of the cooling of the roll and bearing housing
Chinese patent 2011100661204.1 "A device and method for hot rolling and warm rolling of
metal sheet and strip" and its similar
Chinese patent 201110349952.0 "A device and method for hot rolling and warm rolling metal The method of wrapping the metal
pipe frame in the circumferential direction and electrifying it realizes the online heating of the roll by
induction heating, but this method has several shortcomings: (1) It does not consider the temperature uniformity and temperature uniformity of the roll surface along the width direction of the roll.
Temperature gradient control; (2) The cooling of the roll and bearing seat is not considered; (3) Its
heating element occupies most of the space in the circumferential direction of the roll, hindering the use of other
mechanical components and online instruments; (4) In this method The rolling process is not heated in advance, but warm rolling is achieved by accepting the
heat transfer from the rolls
Steckel rolling mill is an existing technology. Its integrally heated in-furnace hot coiler can solve the problem that magnesium coils cannot be uncoiled at
room temperature, but it cannot solve the other problems that must be solved in the above-mentioned coil temperature-controlled rolling. Problem; and the
heat capacity of the coiler in the furnace is large, the temperature in the furnace is difficult to control, the coiling temperature is low, the coiling temperature of the finished product is not easy to control, and the
temperature gradient control in the strip direction cannot be realized
[0013] To sum up, the existing patents only partially solve the technical problems related to single-sheet warm rolling, and there is no single-sheet metal strip warm rolling mill that comprehensively solves all key technical problems of single-sheet metal strip rolling, let alone a single-sheet metal strip warm rolling mill. There is a plan that can fully consider all the technologies to be solved by metal coil rolling, especially there is no plan for high-
silicon steel, aluminum,
titanium, magnesium and other emerging metal material coils. Technology and equipment for temperature-controlled rolling of magnesium and other
metal strips