Technical Field
[0001] The present disclosure relates to a hot-rolling and heat treatment process, particularly
to a hot-rolling on-line thermal insulation heat treatment process and a heat treatment
line.
Background Art
[0002] In traditional hot rolling production processes, due to the complex composition design
and strengthening mechanism of hot-rolled and cold-rolled high-strength steel, uneven
cooling and excessively fast cooling after rolling or coiling have a negative influence
on the performances of finished products, resulting in such problems as fluctuation
of strip steel performances, degradation of plate shape, etc. In order to solve these
problems, after coiling, hot coils are usually sent to a hot-rolled steel finishing
warehouse to receive collective slow cooling with the aid of thermal insulation (using
thermal insulation walls or thermal insulation pits, etc) or off-line heat treatment
(using a roller hearth furnace or a bell furnace, etc.) to alleviate the influence.
However, this leads to increased manufacturing cost, prolonged manufacturing cycle,
among other problems. Moreover, some of the means cannot fully achieve the purpose
of improving performances and plate shape quality.
[0003] Conventional methods for post-coiling heat treatment of hot coils include:
- 1) after coiling, hot coils are sent to a finishing warehouse for slow cooling treatment
using thermal insulation pits or thermal insulation walls;
- 2) after coiling, hot coils are sent to a finishing warehouse where they are stacked
for collective slow cooling, after which plates are cut out using a decoiler set,
and then tempered in a roller hearth furnace;
- 3) after coiling, hot coils are sent to a cold-rolling stage, and then annealed in
a bell furnace for cold-rolled steel.
[0004] The original process flow is: heating - rolling - laminar cooling - coiling - off-line
heat treatment (in a thermal insulation pit or a heat treatment furnace, etc.).
Disadvantages of the prior art:
[0005] In the case where hot coils are sent to a finishing warehouse after coiling, and
then slowly cooled using thermal insulation pits or thermal insulation walls, it generally
takes 30-120 minutes for the hot coils to be transported into the warehouse after
coiling, during which time uneven cooling of the inner cycle, outer cycle and sides
of the strip steel has already occurred due to the fast cooling rate of the hot coils
in air. In addition, there is no heat source in the thermal insulation pits or walls
for providing heat, and thus the slow cooling treatment actually improves the performances
and plate shape quality of the strip steel to a very limited extent.
[0006] In the case of tempering treatment using a roller hearth furnace or annealing treatment
using a bell furnace, uniform heat treatment of strip steel may be realized, but a
huge one-time project investment is required. Moreover, the strip steel needs to be
reheated, which leads to a significant increase in manufacturing cost and a prolonged
manufacturing cycle of the product.
[0007] At present, other steel plants at home and abroad usually treat hot coils by collective
slow cooling with the aid of thermal insulation (using thermal insulation walls or
thermal insulation pits, etc.) in a hot-rolled steel finishing warehouse or off-line
heat treatment (using a roller hearth furnace or a bell furnace, etc.).
[0008] For example, Chinese Patent Application
CN201210338335 discloses a "carrier roller-tray type metal strip coil transport device", wherein
a transport chain tray is used to roll up and transport a steel coil after coiling.
This device comprises a fixed saddle just for transporting a steel coil. It cannot
perform on-line thermal insulation of the steel coil during transportation.
[0009] Chinese Patent Application
CN201710853613.3 discloses an "on-line thermal insulation slow cooling device" which only has thermal
insulation effect. Due to incomplete sealing of its bottom structure, the thermal
insulation effect is not good for steel coils.
[0010] Japanese Patent Publication
JP2010094710 (A) discloses a "tunnel-type thermal insulation enclosure", wherein special thermal
insulation pits and the like are added to the production line, which generally results
in high cost. Moreover, it takes a long period of time to retrofit the production
line, and thus normal production will be affected.
[0011] Korean Patent
KR1589913 (B1) discloses a "mobile tunnel thermal insulation enclosure". Although movement and
thermal insulation are achieved at the same time, the overall mobile equipment is
contained in a thermal insulation chamber, and thus the service life of the equipment
is shortened. Independent thermal insulation of individual objects and a perfect combination
of a thermal insulation enclosure with a transport line cannot be achieved.
[0012] Chinese Patent
CN101413051B discloses a "deep processing system for hot-rolled strip steel", wherein a thermal
insulation tunnel structure is used, but the overall mobile equipment is contained
in a thermal insulation chamber, and thus the service life of the equipment is shortened.
[0013] The following problems exist in the above prior art:
- (1) The most prominent problem of a hot-rolling thermal insulation device is that
the interval between coiling of strip steel and entry of a steel coil into the insulation
device is so long that metallographic structure transformation of the strip steel
has already occurred or has been completed. The effect of off-line slow cooling in
improving hot coil performances cannot meet the quality requirements for high-strength
steel. It will take as long as 20-30 minutes to hoist and transfer the hot coil into
a thermal insulation enclosure, such that the air cooling time of the steel coil is
too long, which affects the thermal insulation effect and material properties.
- (2) The cost of adding special thermal insulation pits, thermal insulation furnaces,
bell furnaces, heat treatment lines and the like to a production line is generally
high. Moreover, it takes a long period of time to retrofit the production line, and
thus normal production will be affected. In addition, there is a problem that the
thermal insulation effect is not good (i.e. temperature drops fast).
- (3) Thermal insulation enclosures are nearly all in off-line mode (the thermal insulation
devices are statically positioned on a coiling platform), and transportation of steel
coils disrupts the normal production rhythm of a production line. The production capacity
of the rolled steel production line is affected, and bulk production is practically
difficult.
- (4) Semi-closed "tunnel" insulation using a transport chain or the thermal insulation
technology using a vertical transportation mode has the disadvantages of, inter alia,
insufficient insulating time and poor thermal insulation effect of steel coils in
large-scale production, and thus they are very difficult to be put into practice.
Summary
[0014] An object of the present disclosure is to provide a hot-rolling on-line movable thermal
insulation heat treatment process and a heat treatment line, wherein the coiling process
temperature for a hot coil is effectively exploited to efficiently perform thermal
insulation heat treatment on the hot coil at the earliest time. The thermally insulated
hot coil moves on-line along with a thermal insulation device to ensure meeting differentiated
heat treatment process requirements. Not only product performances can be improved
effectively, but also one-time investment is low. The needs of high-speed large-scale
production can be satisfied, and energy can be saved.
[0015] To achieve the above object, the technical solution of the present disclosure is
as follows:
A hot-rolling on-line movable thermal insulation heat treatment process, wherein a
slab is heated, rolled, laminar-flow cooled, and coiled to a hot coil state; after
the hot coil is unloaded and bundled, a movable hot coil thermal insulation heat treatment
device is applied to the hot coil within 30 minutes to start heat treatment on the
hot coil while the hot coil is simultaneously transported on-line to a hot coil thermal
insulation treatment zone; after heat treatment for a period of time of 1 to 48 hours,
the steel coil is cooled in air and then sent to a warehouse, wherein a coiling temperature
is controlled between 250 °C and 750 °C.
[0016] Preferably, the movable hot coil thermal insulation heat treatment device is applied
to the hot coil within 10 minutes after the coiling is completed.
[0017] Preferably, the movable hot coil thermal insulation heat treatment device is a transport
cart with a thermal insulation enclosure.
[0018] Preferably, a natural cooling rate in the movable hot coil thermal insulation heat
treatment device is from 1 to 10 °C/h.
[0019] Preferably, a heating system and/or a vacuuming system and/or an inert gas filling
system are provided in the movable hot coil thermal insulation heat treatment device.
[0020] For traditional hot-rolled and cold-rolled high-strength steel, in most cases, solid
solution strengthening, fine grain strengthening, phase transformation strengthening,
precipitation strengthening, and other strengthening mechanisms are adopted to meet
structural performance requirements, wherein both the composition design and TMCP
process are rather complicated. Uniformity of both strength properties and post-coiling
properties has a lot to do with temperature maintenance and cooling uniformity of
the hot coil. In the course of natural cooling, fluctuation of properties in a length
or width direction is prevalent. In order to substantially address the above problems,
a relatively feasible method at present is employment of off-line heat treatment,
wherein after coiling and cooling, the coil is reheated to a certain process temperature,
and subjected to thermal insulation treatment. Product properties are improved by
a tempering or annealing process.
[0021] For hot-rolled and cold-rolled high-strength steel, a coiling process temperature
is usually between 250 °C and 750 °C, which is the same as the temperature range for
an off-line heat treatment process. This technical route can control the coiling temperature
precisely, and implement the on-line heat treatment of the hot coil at a reasonable
process temperature with the use of a thermal insulation process equipment before
the hot coil cools down naturally. Tempering or annealing heat treatment of the hot
coil is fulfilled by thermal insulation treatment for a certain period of time. The
process treatment effect is equivalent to that of the off-line heat treatment. However,
as compared to the off-line heat treatment, equipment investment and energy consumption
are saved, and a green, sustainable heat treatment process is realized.
[0022] According to the present disclosure, there is provided a hot-rolling on-line movable
thermal insulation heat treatment line, wherein a heat treatment transport chain roller
bed is provided between a bundling device downstream of a hot-rolled steel coiler
and a cold rolling set; at least one movable hot coil thermal insulation heat treatment
device is provided on the heat treatment transport chain roller bed; correspondingly,
a hoisting device capable of loading and unloading a steel coil to the movable hot
coil thermal insulation heat treatment device is provided at each end of the heat
treatment transport chain roller bed; and a thermal insulation enclosure for closed
on-line thermal insulation of the hot-rolled steel coil is provided on the movable
hot coil thermal insulation heat treatment device.
[0023] Further, a steel coil thermal insulation zone is provided at one side of the heat
treatment transport chain roller bed, and at least one thermal insulation transport
chain roller bed coupled to the heat treatment transport chain roller bed is provided
in the steel coil thermal insulation zone.
[0024] In addition, at least one heat treatment work station is provided on the heat treatment
transport chain roller bed or the thermal insulation transport chain roller bed, and
a heating system for heating an interior of the thermal insulation enclosure in the
movable hot coil thermal insulation heat treatment device and/or a protective cooling
gas input system for gas cooling are provided in the heat treatment work station.
[0025] Furthermore, an information code printing device for printing steel coil information
on the steel coil is provided at one end of the heat treatment transport chain roller
bed facing the cold rolling set.
[0026] Preferably, the movable hot coil thermal insulation heat treatment device comprises
a baseboard; a steel coil fixture provided at a central portion of an upper end surface
of the baseboard; a tray which is an annular structure and horizontally arranged by
nesting at a middle part of the steel coil fixture; a thermal insulation enclosure,
which has an open lower end and an inner chamber having a volume larger than the steel
coil, wherein the thermal insulation enclosure is arranged on the tray; an electric
heating device provided on an inner side wall of the thermal insulation enclosure;
a temperature sensor provided in the thermal insulation enclosure; and an information
acquisition control module, wherein the electric heating device and the temperature
sensor are electrically coupled to the information acquisition control module.
[0027] Preferably, the movable hot coil thermal insulation heat treatment device further
comprises a gas protection device and a gas sensor which are electrically coupled
to the information acquisition control module, respectively.
[0028] Preferably, a signal emitting module is provided in the information acquisition control
module.
[0029] Preferably, the steel coil fixture comprises two juxtaposed support bodies, wherein
upper end faces of the two support bodies are inclined surfaces and are arranged symmetrically;
and a side sealing device is arranged at a gap between the two support bodies at each
of two sides of the two support bodies.
[0030] Preferably, a bottom sealing device is arranged between bottoms of the two support
bodies of the steel coil fixture to close the gap between the bottoms of the two support
bodies.
[0031] Preferably, the bottom sealing device comprises a support plate provided between
the two support bodies of the steel coil fixture, wherein the support plate is arranged
vertically, and a plurality of rollers are provided on lower parts of two sides of
the support plate at even spacings in a length direction to form a slidable mechanism;
and a sealing plate provided horizontally on a top surface of the support plate, wherein
the sealing plate has a size corresponding to the gap between the bottoms of the two
support bodies.
[0032] Preferably, an electromagnetic block is provided on an end face of the support plate,
and correspondingly, a metal stopper matching the electromagnetic block is provided
between end portions of the two support bodies of the steel coil fixture at one side.
[0033] Preferably, the side sealing devices comprise:
two fixed baseboards, each arranged horizontally at a bottom of the gap at an outer
side of the two support bodies of the steel coil fixture, wherein a plurality of guide
rollers spaced in an axial direction are provided on an outer side surface of each
of the fixed baseboards;
two sealing members, each arranged at the gap at one of the two sides of the two support
bodies of the steel coil fixture, wherein a bottom end of the sealing member is provided
slidably on the guide rollers of the fixed baseboard; and
a driving mechanism, comprising: two racks, each provided horizontally on one of the
two sealing members with one end of the rack being coupled to the sealing member;
a drive shaft, arranged horizontally at a side of the support body opposite to the
gap through two bearing pedestals; two gears, each provided at one of two ends of
the drive shaft, wherein the gear meshes with the rack.
[0034] Preferably, the bearing pedestal is provided on one side of the support body by using
a fixing plate, wherein one side of the fixing plate is provided with a through hole
for the rack to pass through, and a roller abutted against a top surface of the rack
is provided at an outer side of the fixing plate above the through hole.
[0035] Preferably, the sealing plate and the sealing member have a composite layered structure,
wherein an intermediate part of the structure is an insulating felt, and two sides
of the intermediate part are cladded with a high temperature resistant steel plate.
[0036] Preferably, the sealing member is a right angle plate structure.
[0037] Preferably, a positioning sleeve is provided on a lower part of a side of the thermal
insulation enclosure. Correspondingly, a positioning pin matching the positioning
sleeve is provided on the tray for the thermal insulation enclosure. The positioning
pin is preferably a cone-shaped body.
[0038] Preferably, the thermal insulation enclosure is provided with a ventilation hole
and a corresponding exhaust valve.
[0039] Preferably, the thermal insulation enclosure has a composite structure, comprising:
an outer protection layer, which is a high-strength steel plate; an intermediate layer,
which is a thermal insulation material; and an inner layer, which is a high temperature
resistant stainless steel plate.
[0040] Preferably, the thermal insulation enclosure is a composite structure, comprising
an inner radiation layer, an electric heating wire layer, an intermediate mesh cover,
an intermediate thermal insulation layer, and an outer protection layer in order from
inside to outside.
[0041] Preferably, the electric heating device is an electric heating wire, and the temperature
sensor is a thermocouple sensor.
[0042] In the hot-rolling on-line movable thermal insulation heat treatment line of the
present disclosure:
After the strip steel is coiled, the steel coil transport cart transports the steel
coil to the tray, and then the thermal insulation device is placed on the tray to
insulate the steel coil at the earliest time.
[0043] The thermal insulation enclosure and the steel coil move normally along the transport
chain roller bed with no influence on the production operation of succeeding steel
coils, while heat treatment is implemented during transportation.
[0044] Transport cart lateral transmission roller bed device: this device transfers an unloaded
transport cart device bearing no thermal insulation enclosure from a back-haul transport
chain roller bed to the heat treatment transport chain roller bed to realize transmission
of the transport cart device to ensure that the transport cart can continue to receive
another hot-rolled steel coil coming from the coiling station.
[0045] The thermal insulation enclosure hoisting device lifts the thermal insulation enclosure
from the transport cart device that carries the thermal insulation enclosure and moves
on the back-haul transport chain roller bed, and then transfers the thermal insulation
enclosure to the heat treatment transport chain roller bed to wait for next operation.
When the hot-rolled steel that has been coiled is placed on the transport cart device,
a thermal insulation enclosure up-transfer hoisting device automatically places the
thermal insulation enclosure on the transport cart device to achieve thermal insulation
of the hot-rolled steel coil after the coiling of the steel.
[0046] The transport cart device bearing a thermal insulation enclosure can satisfy the
requirement of on-line heat treatment of a steel coil. The transport cart device can
move on the transport chain roller bed and transport the steel coil that has been
hot rolled and coiled to the thermal insulation zone of the transport chain to accomplish
heat treatment. The thermal insulation enclosure and the transport cart device can
be separated and combined by using a thermal insulation enclosure up-transfer hoisting
device and a thermal insulation enclosure down-transfer hoisting device.
[0047] Single thermal insulation enclosure zone: a steel coil is subjected to thermal insulation
heat treatment in a transport cart device bearing a thermal insulation enclosure.
The purpose of heat treatment is achieved by controlling the running time of the transport
cart device bearing a thermal insulation enclosure on the heat treatment transport
chain roller bed.
[0048] The layout of the single thermal insulation enclosure zone needs to be coordinated
with the transport cart devices bearing thermal insulation enclosures, with the number
of hot-rolled steel coils to be insulated and the time of insulation being taken into
account. Assuming that the number of thermal insulation enclosures for hot steel coils
is n, the number of steel coil transport carts on the production line should be >
n + 1. After a thermal insulation enclosure is separated from a transport cart device
at the thermal insulation enclosure down-transfer hoisting device, the thermal insulation
enclosure, together with the transport cart, returns to the up-transfer hoisting device
along the back-haul transport chain roller bed.
[0049] According to the present disclosure, special batches of hot-rolled strip steel can
be subjected to special treatment such as in-depth processing when necessary, and
heat treatment work stations can be added in the thermal insulation zone. The heat
treatment work station is provided with a heating system for heating the interior
of the thermal insulation enclosure and a protective cooling gas input system.
[0050] For hot-rolled strip steel that needs to be heated, a hot-rolled strip steel transport
cart transports the hot-rolled steel coil to a work station where the heating system
for heating the interior will heat the hot-rolled strip steel. Relevant heat treatment
curves and process requirements may be utilized to perform the secondary heating of
the steel coil to improve the overall performances of the hot-rolled strip steel.
[0051] In the case that hot-rolled strip steel needs gas protection and rapid controlled
cooling, the transport cart device carrying a thermal insulation enclosure that has
entered the processing work station is coupled to the protective cooling gas input
system. The requirement for controlling the internal temperature of the thermal insulation
enclosure device may be fulfilled by controlling the volume and proportion of the
protective gas that is input. Relevant heat treatment curves and process requirements
may be utilized to perform the secondary heating of the steel coil to improve the
overall performances of the hot-rolled strip steel.
[0052] After the thermal insulation enclosure is separated from the hot-rolled steel strip,
the hot-rolled strip steel transport cart transports the hot-rolled strip steel to
an information code printing station where the coil information will be printed on
the steel coil. After it's confirmed that the steel coil separated from the thermal
insulation enclosure carries the steel coil information, the steel coil is conveyed
to the next production line for further processing.
[0053] After the information printing step is completed, the heat-treated steel coil is
transported along the transport chain roller bed to a steel coil warehouse, or transported
via the transport chain system to the next working procedure of the production line
to continue the production.
[0054] According to the present disclosure, the processing line is also provided with a
heat treatment work station and an information code printing device. A special batch
of hot-rolled strip steel may need to be subjected to special treatment such as in-depth
processing in the heat treatment work station. A heat treatment work station may be
added in the thermal insulation zone. The heat treatment work station is provided
with a heating system for heating the interior of the thermal insulation enclosure
and a protective cooling gas input system.
[0055] Information code printing device: a hot-rolled strip steel transport cart transports
the hot-rolled strip steel to an information code printing station where the coil
information will be printed on the steel coil.
[0056] Heat-treated steel coils may be transported along the transport chain roller bed
to a steel coil warehouse. If a steel coil needs cold rolling, flattening or trimming,
a transport cart rotating roller bed device is used to transfer the steel coil to
a transport chain roller bed in the next working procedure.
[0057] It is a pioneering technology to complete thermal insulation, soaking and slow cooling
of a steel coil using steel coil transport equipment on line. The thermal insulation
enclosure exists individually and independently, and the temperature of each steel
coil can be controlled during transportation on the transport chain. This saves time,
and also improves production rhythm and efficiency.
[0058] The beneficial effects of the present disclosure include:
According to the present disclosure, the hot-rolling on-line movable thermal insulation
heat treatment process realizes on-line movable heat treatment of a hot coil by using
a thermal insulation device directly after coiling of the hot coil. When this process
is used in place of the traditional off-line heat treatment, the purpose of improving
product performances and plate shape quality, saving energy and reducing consumption
can be achieved.
[0059] Thermal insulation heat treatment of hot-rolled and cold-rolled high-strength steel
hot coils in an "on-line mode" avoids the influence of air cooling after coiling on
the performances of the steel coils, and improves the performances of the hot-rolled
and cold-rolled high-strength steel.
[0060] The present disclosure realizes on-line heat treatment during the transport chain
transportation for a hot-rolled steel coil after coiling. After the steel coil leaves
a coiler where the coiling is done, a movable hot coil thermal insulation heat treatment
device is applied to the steel coil immediately. The heat of the steel coil itself
is exploited to implement the heat treatment process including soaking and slow cooling
of the steel coil to achieve the goals of high efficiency, energy saving and high
yield rate.
[0061] On the production line according to the present disclosure, after coiling, the strip
steel coil is subjected to thermal insulation treatment at the earliest time. This
greatly addresses the challenges of insufficient performance improvement caused by
the excessively long time from coiling to entry of the steel coil to the slow cooling
device, and large performance fluctuation of the strip steel in the length and width
directions. In addition, severe fluctuation of rolling force in cold rolling production,
and failure to meet the tolerance standard for the thickness of final cold-rolled
products are avoided. The rolling stability of cold-rolling - pickling - continuous
rolling mills is improved, and the yield rate of cold-rolled ultra-high-strength steel
is increased.
- 1. Real time: thermal insulation treatment of a hot coil is implemented directly after
coiling, and the interval is short.
- 2. On line: thermal insulation of a hot coil is implemented directly on a transport
chain with no redundant process.
- 3. Economy: residual heat of a steel coil is exploited to implement the post-coiling
heat treatment, which is energy saving and environmentally friendly.
- 4. Process: the thermal insulation effect is ideal, and the requirements of high-strength
steel on thermal insulation process can be satisfied.
Description of the Drawings
[0062]
Figs. 1 and 2 are schematic graphs showing the influence of on-line movable insulation
on steel coil performances.
Fig. 3 is a schematic view of an embodiment of a hot-rolled strip steel heat treatment
line according to the present disclosure.
Fig. 4 is a schematic view of an embodiment of a hot-rolled strip steel heat treatment
line according to the present disclosure.
Fig. 5 is a schematic view of an embodiment of a hot-rolled strip steel heat treatment
line according to the present disclosure.
Fig. 6 is a schematic view showing the structure of a movable hot coil thermal insulation
heat treatment device in Example 1 according to the present disclosure.
Fig. 7 is a side view of the movable hot coil thermal insulation heat treatment device
in Example 1 according to the present disclosure.
Fig. 8 is a front view of the movable hot coil thermal insulation heat treatment device
in Example 2 according to the present disclosure.
Fig. 9 is a front view of the movable hot coil thermal insulation heat treatment device
in Example 3 according to the present disclosure.
Fig. 10 is a partial cutaway view of the thermal insulation enclosure in the movable
hot coil thermal insulation heat treatment device in the Examples according to the
present disclosure.
Fig. 11 is a stereogram of the movable hot coil thermal insulation heat treatment
device in Example 1 according to the present disclosure.
Fig. 12 is a front view of the movable hot coil thermal insulation heat treatment
device in Example 1 according to the present disclosure.
Fig. 13 is a stereogram of the bottom sealing device in the movable hot coil thermal
insulation heat treatment device in Example 1 according to the present disclosure.
Fig. 14 is a front view of the movable hot coil thermal insulation heat treatment
device in Example 1 according to the present disclosure.
Fig. 15 is a side view of the device shown in Fig. 14.
Fig. 16 is an upward stereogram of the movable hot coil thermal insulation heat treatment
device in Example 1 according to the present disclosure.
Fig. 17 is an enlarged schematic view of part A in Fig. 16.
Detailed Embodiments
[0063] A hot-rolling on-line movable thermal insulation heat treatment process is provided
according to the present disclosure, wherein a slab is heated, rolled, laminar-flow
cooled, and coiled to a hot coil state; after the hot coil is unloaded and bundled,
a movable hot coil thermal insulation heat treatment device is applied to the hot
coil within 30 minutes to start heat treatment on the hot coil while the hot coil
is simultaneously transported on-line to a hot coil thermal insulation treatment zone;
after heat treatment for a period of time of 1 to 48 hours, the steel coil is cooled
in air and then sent to a warehouse, wherein a coiling temperature is controlled between
250 °C and 750 °C.
[0064] Preferably, the movable hot coil thermal insulation heat treatment device is applied
to the hot coil within 10 minutes after the coiling is completed.
[0065] Preferably, the movable hot coil thermal insulation heat treatment device is a transport
cart with a thermal insulation enclosure.
[0066] Preferably, a natural cooling rate in the movable hot coil thermal insulation heat
treatment device is from 1 to 10 °C/h.
[0067] Preferably, a heating system and/or a vacuuming system and/or an inert gas filling
system are provided in the movable hot coil thermal insulation heat treatment device.
[0068] Referring to Figs. 1 and 2, according to the present disclosure, the thermal insulation
heat treatment of hot-rolled and cold-rolled high-strength steel hot coils in an "on-line
mode" avoids the influence of air cooling after coiling on the performances of the
steel coils, and improves the performances of the hot-rolled and cold-rolled high-strength
steel.
[0069] Referring to Fig. 3, according to the present disclosure, there is provided a hot-rolled
strip steel heat treatment line, wherein a heat treatment transport chain roller bed
30 is provided between a bundling device 20 downstream of a hot-rolled steel coiler
10 and a cold rolling set; at least one movable hot coil thermal insulation heat treatment
device 40 is provided on the heat treatment transport chain roller bed 30; correspondingly,
hoisting devices 50, 50' capable of loading and unloading a steel coil to the movable
hot coil thermal insulation heat treatment device are positioned respectively at two
ends of the heat treatment transport chain roller bed 30; and a thermal insulation
enclosure for closed on-line thermal insulation of the hot-rolled steel coil is provided
on the movable hot coil thermal insulation heat treatment device 40.
[0070] Referring to Fig. 4, at least one heat treatment work station 80 is provided on the
heat treatment transport chain roller bed 30 or the thermal insulation transport chain
roller bed 70; a heating system for heating an interior of the thermal insulation
enclosure in the movable hot coil thermal insulation heat treatment device and/or
a protective cooling gas input system for gas cooling are provided in the heat treatment
work station 80; 90 represents a rotating roller bed.
[0071] Referring to Fig. 5, a steel coil thermal insulation zone 60 is provided on one side
of the heat treatment transport chain roller bed 10, wherein at least one thermal
insulation transport chain roller bed 70 coupled to the heat treatment transport chain
roller bed 70 and a hoisting device 50" are provided in the steel coil thermal insulation
zone 60.
[0072] Referring to Fig. 5, an information code printing device 90 for printing steel coil
information on the steel coil is provided at one end of the heat treatment transport
chain roller bed 30 facing the cold rolling set.
[0073] Referring to Figs. 5-17, the movable hot coil thermal insulation heat treatment device
40 according to the present disclosure comprises:
a baseboard 1;
a steel coil fixture 2 provided at a central portion of an upper end surface of the
baseboard 1;
a tray 3 having an annular structure, wherein the tray 3 is horizontally arranged
by nesting at a middle part of the steel coil fixture 2;
a thermal insulation enclosure 4, which has an open lower end and an inner chamber
having a volume larger than a steel coil 100, wherein the thermal insulation enclosure
4 is arranged on the tray 3;
an electric heating device 5 provided on an inner side wall of the thermal insulation
enclosure 4;
a temperature sensor 6 provided in the thermal insulation enclosure 4; and
an information acquisition control module 7, wherein the electric heating device 5
and the temperature sensor 6 are electrically coupled to the information acquisition
control module 7.
[0074] Further, it further comprises a gas protection device and gas sensors 8, 8' which
are electrically coupled to the information acquisition control module 7, respectively.
[0075] Preferably, a signal emitting module is provided in the information acquisition control
module 7.
[0076] Preferably, the steel coil fixture 2 comprises two juxtaposed support bodies 21,
22, wherein upper end faces of the two support bodies 21, 22 are inclined surfaces
and are arranged symmetrically; and side sealing devices 9, 9' are arranged at a gap
between the two support bodies 21, 22 at two sides of the two support bodies 21, 22.
[0077] Still further, a bottom sealing device 11 is arranged between bottoms of the two
support bodies 21, 22 of the steel coil fixture 2 to close the gap between the bottoms
of the two support bodies 21, 22.
[0078] Preferably, the bottom sealing device 11 comprises:
a support plate 111 provided between the two support bodies 21, 22 of the steel coil
fixture 2, wherein the support plate 111 is arranged vertically, and a plurality of
rollers 112 are provided on lower parts of two sides of the support plate 111 at even
spacings in a length direction to form a slidable mechanism; and
a sealing plate 113 provided horizontally on a top surface of the support plate 111,
wherein the sealing plate has a size corresponding to the gap between the bottoms
of the two support bodies 21, 22.
[0079] Preferably, the sealing plate 113 has a composite layered structure, wherein an intermediate
part of the structure is consisting of an insulating felt, and two side parts are
high temperature resistant steel plates.
[0080] Preferably, an electromagnetic block 114 is provided on an end face of the support
plate 111, and correspondingly, a metal stopper matching the electromagnetic block
114 is provided between end portions of the two support bodies 21, 22 of the steel
coil fixture 2 at one side.
[0081] Referring to Figs. 15-17, the side sealing device 9 (which is taken as an example;
the same below) comprises:
two fixed baseboards 91, 91' respectively provided horizontally at a bottom of the
gap at an outer side of the two support bodies 21, 22 of the steel coil fixture 2,
wherein a plurality of guide rollers 92, 92' spaced in an axial direction are provided
on an outer side surface of the fixed baseboards 91, 91';
two sealing members 93, 93' respectively arranged at the gap at two sides of the two
support bodies 21, 22 of the steel coil fixture 2, wherein bottom ends of the sealing
members 93, 93' are provided slidably on the guide rollers 92, 92' of the fixed baseboard
91;
a driving mechanism 94, comprising:
two racks 941 respectively provided horizontally on the two sealing members 93, 93'
with one end of the rack 941 being coupled to the sealing members 93, 93';
a drive shaft 942, arranged horizontally at a side of the support body 21 opposite
to the gap through two bearing pedestals 943, wherein a gear 944 is provided at each
of two ends of the drive shaft 942, wherein the gear 943 meshes with the rack 941.
[0082] Preferably, the bearing pedestal 943 is provided on one side of the support body
221 by using a fixing plate 944, wherein one side of the fixing plate 945 is provided
with a through hole 9451 for the rack 941 to pass through, and a roller 946 abutted
against a top surface of the rack 941 is provided at an outer side of the fixing plate
945 above the through hole 945.
[0083] Preferably, the sealing member 93 has a composite layered structure, wherein an intermediate
part of the structure is an insulating material, and two sides of the intermediate
part are cladded with a high temperature resistant steel plate.
[0084] Preferably, the sealing member 93 is a right angle plate structure.
[0085] Preferably, a positioning sleeve 12 is provided on a lower part of a side of the
thermal insulation enclosure 4. Correspondingly, a positioning pin 13 matching the
positioning sleeve 12 is provided on the tray 3 for the thermal insulation enclosure.
The positioning pin 13 is preferably a cone-shaped body.
[0086] Preferably, the thermal insulation enclosure 4 is provided with a ventilation hole
and a corresponding exhaust valve 41.
[0087] Preferably, the thermal insulation enclosure 4 has a composite structure, comprising:
an outer protection layer, which is a high-strength steel plate; an intermediate layer,
which is a thermal insulation material; and an inner layer, which is a high temperature
resistant stainless steel plate.
[0088] Preferably, the thermal insulation enclosure 4 is a composite structure, comprising
an inner radiation layer 42, an electric heating wire layer 43, an intermediate mesh
cover 44, an intermediate thermal insulation layer 45, and an outer protection layer
46 in order from inside to outside. The composite structure of the thermal insulation
enclosure is fixed with an anchor nail 47.
[0089] Referring to Figs. 5 and 6, the thermal insulation enclosure 4 is a square thermal
insulation enclosure or a circular thermal insulation enclosure.
[0090] Preferably, the electric heating device 5 is an electric heating wire, and the temperature
sensor 6 is a thermocouple sensor.
[0091] The thermal insulation treatment of a strip steel coil after coiling according to
the present disclosure also fulfils the purpose of annealing treatment by making use
of the residual heat in the steel coil that has just been coiled, which greatly addresses
the challenges of insufficient performance improvement caused by the excessively long
time from coiling to entry of the steel coil to the slow cooling device, and large
performance fluctuation of the strip steel in the length and width directions.
[0092] A special batch of hot-rolled strip steel may need to be subjected to special treatment
such as in-depth processing. The heating device and protective cooling gas input system
provided in the thermal insulation enclosure can cooperate to achieve temperature
control under necessary conditions.
1. A hot-rolling on-line movable thermal insulation heat treatment process, wherein a
slab is heated, rolled, laminar-flow cooled, and coiled to a hot coil state; after
the hot coil is unloaded and bundled, a movable hot coil thermal insulation heat treatment
device is applied to the hot coil within 30 minutes to start heat treatment on the
hot coil while the hot coil is simultaneously transported on-line to a hot coil thermal
insulation treatment zone; after heat treatment for a period of time of 1 to 48 hours,
the steel coil is cooled in air and then sent to a warehouse, wherein a coiling temperature
is controlled between 250 °C and 750 °C.
2. The hot-rolling on-line movable thermal insulation heat treatment process according
to claim 1, wherein the movable hot coil thermal insulation heat treatment device
is applied to the hot coil within 10 minutes after the coiling is completed.
3. The hot-rolling on-line movable thermal insulation heat treatment process according
to claim 1, wherein the movable hot coil thermal insulation heat treatment device
is a transport cart with a thermal insulation enclosure.
4. The hot-rolling on-line movable thermal insulation heat treatment process according
to claim 1, wherein a natural cooling rate within the movable hot coil thermal insulation
heat treatment device is from 1 to 10 °C/h.
5. The hot-rolling on-line movable thermal insulation heat treatment process according
to claim 1 or 2 or 3, wherein a heating system and/or a vacuuming system and/or an
inert gas filling system are provided in the movable hot coil thermal insulation heat
treatment device.
6. A hot-rolling on-line movable thermal insulation heat treatment line, wherein a heat
treatment transport chain roller bed is provided between a bundling device downstream
of a hot-rolled steel coiler and a cold rolling set; at least one movable hot coil
thermal insulation heat treatment device is positioned on the heat treatment transport
chain roller bed; correspondingly, a hoisting device capable of loading and unloading
a steel coil to the movable hot coil thermal insulation heat treatment device is positioned
at each end of the heat treatment transport chain roller bed; and a thermal insulation
enclosure for closed on-line thermal insulation of the hot-rolled steel coil is positioned
on the movable hot coil thermal insulation heat treatment device.
7. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 6, wherein a steel coil thermal insulation zone is provided at one side of the
heat treatment transport chain roller bed, and at least one thermal insulation transport
chain roller bed coupled to the heat treatment transport chain roller bed is provided
in the steel coil thermal insulation zone.
8. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 6, wherein at least one heat treatment work station is provided on the heat
treatment transport chain roller bed or the thermal insulation transport chain roller
bed, and a heating system for heating an interior of the thermal insulation enclosure
in the movable hot coil thermal insulation heat treatment device and/or a protective
cooling gas input system for gas cooling are provided in the heat treatment work station.
9. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 6, wherein an information code printing device for printing steel coil information
on the steel coil is provided at one end of the heat treatment transport chain roller
bed facing the cold rolling set.
10. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 6 or 8, wherein the movable hot coil thermal insulation heat treatment device
comprises:
a baseboard;
a steel coil fixture provided at a central portion of an upper end surface of the
baseboard;
a tray which is an annular structure and horizontally arranged by nesting at a middle
part of the steel coil fixture;
a thermal insulation enclosure, which has an open lower end and an inner chamber having
a volume larger than a steel coil, wherein the thermal insulation enclosure is arranged
on the tray;
an electric heating device provided on an inner side wall of the thermal insulation
enclosure;
a temperature sensor provided in the thermal insulation enclosure; and
an information acquisition control module, wherein the electric heating device and
the temperature sensor are electrically coupled to the information acquisition control
module.
11. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10, wherein the movable hot coil thermal insulation heat treatment device further
comprises a gas protection device and a gas sensor which are electrically coupled
to the information acquisition control module, respectively.
12. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10, wherein a signal emitting module is provided in the information acquisition
control module.
13. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10, wherein the steel coil fixture comprises two juxtaposed support bodies,
wherein upper end faces of the two support bodies are inclined surfaces and are arranged
symmetrically; and a side sealing device is arranged at a gap at each of two sides
of the two support bodies.
14. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10, wherein a bottom sealing device is arranged between bottoms of the two support
bodies of the steel coil fixture to close the gap between the bottoms of the two support
bodies.
15. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 14, wherein the bottom sealing device comprises:
a support plate provided between the two support bodies of the steel coil fixture,
wherein the support plate is arranged vertically, and a plurality of rollers are provided
on lower parts of two sides of the support plate at even spacings in a length direction
to form a slidable mechanism; and
a sealing plate provided horizontally on a top surface of the support plate, wherein
the sealing plate has a size corresponding to the gap between the bottoms of the two
support bodies.
16. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 15, wherein an electromagnetic block is provided on an end face of the support
plate, and correspondingly, a metal stopper matching the electromagnetic block is
provided between end portions of the two support bodies of the steel coil fixture
at one side.
17. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 13, wherein the side sealing device comprises:
two fixed baseboards each provided horizontally at a bottom of the gap at an outer
side of the two support bodies of the steel coil fixture, wherein a plurality of guide
rollers spaced in an axial direction are provided on an outer side surface of each
of the fixed baseboards;
two sealing members, each arranged at the gap at one of the two sides of the two support
bodies of the steel coil fixture, wherein a bottom end of the sealing member is provided
slidably on the guide rollers of the fixed baseboard; and
a driving mechanism, comprising:
two racks, each provided horizontally on one of the two sealing members with one end
of the rack being coupled to the seal member; and
a drive shaft, arranged horizontally at a side of the support body opposite to the
gap through two bearing pedestals; two gears, each provided at one of two ends of
the drive shaft, wherein the gear meshes with the rack.
18. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 17, wherein the bearing pedestal is provided on one side of the support body
by using a fixing plate, wherein one side of the fixing plate is provided with a through
hole for the rack to pass through, and a roller abutted against a top surface of the
rack is provided at an outer side of the fixing plate above the through hole.
19. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 15 or 17, wherein the sealing plate and the sealing member have a composite
layered structure, wherein an intermediate part of the structure is an insulating
felt, and two sides of the intermediate part are cladded with a high temperature resistant
steel plate.
20. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10, wherein a positioning sleeve is provided on a lower part of a side of the
thermal insulation enclosure; correspondingly, a positioning pin matching the positioning
sleeve is provided on the tray for the thermal insulation enclosure; the positioning
pin is preferably a cone-shaped body.
21. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10 or 20, wherein the thermal insulation enclosure is provided with a ventilation
hole and a corresponding exhaust valve.
22. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10 or 20 or 21, wherein the thermal insulation enclosure has a composite structure,
comprising: an outer protection layer, which is a high-strength steel plate; an intermediate
layer, which is a thermal insulation material; and an inner layer, which is a high
temperature resistant stainless steel plate.
23. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10 or 20 or 21, wherein the thermal insulation enclosure is a composite structure,
comprising an inner radiation layer, an electric heating wire layer, an intermediate
mesh cover, an intermediate thermal insulation layer, and an outer protection layer
in order from inside to outside.
24. The hot-rolling on-line movable thermal insulation heat treatment line according to
claim 10, wherein the electric heating device is an electric heating wire, and the
temperature sensor is a thermocouple sensor.