High-efficiency double-frame double-cutting line feed-through intermediate thickness slab production line and production method

Abstract

An efficient straight through medium-heavy plate production line of double rack and double shearing line and a production method are provided. The medium-heavy plate production line comprises: a main rolling line, at least two parallel shearing lines, and straightening stacking lines that are each configured parallel outside each of the shearing lines, the main rolling line comprises: a heating furnace, a high pressure water descaling machine, a fixed width press, a stand roller, a four-roll roughing mill, an intermediate cooling device, a four-roll finishing mill, an ACC accelerated cooling device, a hot straightening machine, a 1 # labeling device and a hot segmenting shear are arranged in order, and a 1 # cooling bed, a 1 # inspection stand, a 2 # cooling bed and a 2 # inspection stand are arranged at two sides of the steel rolling and delivery rolling way; a plate turnover machine; and a traverse stand.

1 . An efficient straight through medium-heavy plate production line of double rack and double shearing line, characterized in comprising: a main rolling line, at least two shearing lines that are configured in parallel, and straightening stacking lines that are each configured in parallel outside each of the shearing lines, wherein one of the shearing lines is arranged in a straight-through relationship with the main rolling line, in which:
 the main rolling line comprises: a heating furnace, a high pressure water descaling machine, a fixed width press, a stand roller, a four-roll roughing mill, an intermediate cooling device, a four-roll finishing mill, an ACC accelerated cooling device, a hot straightening machine,  1 # labeling device and a hot segmenting shear arranged along a steel rolling and delivery rolling way in order, and a  1 # cooling bed, a  1 # inspection stand, a  2 # cooling bed and a  2 # inspection stand are respectively arranged at two sides of the steel rolling and delivery rolling way;   one of the shearing lines is arranged in a straight-through relationship with the steel rolling and delivery rolling way of the main rolling line; each of the shearing lines comprises a shearing and delivery rolling way, and an ultrasonic flaw detector, a crop shear, a bilateral shear, a  2 # labeling device, a cut-to-length shear, a  3 # labeling device and a pre-stacker are arranged long the shearing and delivery rolling way in order; and, a plate turnover machine is arranged between the shearing lines;   the straightening stacking line comprises a straightening and delivery rolling way, and a cold straightening machine, a  4 # labeling device and finished product collection stands at both sides of the straightening and delivery rolling way are arranged long the straightening and delivery rolling way in order; and   a traverse stand is arranged between the shearing line and the straightening stacking line.   
     
     
         2 . The efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 1 , wherein the  1 # cooling bed is arranged at one side of the steel rolling and delivery rolling way before the hot segmenting shear. 
     
     
         3 . The efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 1 , wherein there are at least three heating furnaces, and a deburring machine and a weighting machine are arranged along the heating furnace rolling way in order. 
     
     
         4 . The efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 3 , wherein the heating furnace rolling way is arranged in a straight-through relationship with a continuous casting rolling way. 
     
     
         5 . The efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 1 , wherein a slab library is arranged at one side of the heating furnaces, and one operation chamber is configured for the slab library and the heating furnaces; and, in the main rolling line, one operation chamber is configured for the four-roll finishing mill to the ACC accelerated cooling device. 
     
     
         6 . The efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 1 , wherein the two shearing lines are respectively arranged in two factory spans. 
     
     
         7 . The efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 1  or  6 , wherein several operation chambers for simultaneously controlling the apparatuses corresponding to the two shearing lines are arranged between the two parallel shearing lines, wherein one operation chamber is configured for the hot straightening machine, the cooling bed, the inspection stand, the ultrasonic flaw detector and the crop shear; one operation chamber is configured for the bilateral shear; and one operation chamber is configured for the cut-to-length shear, the inspection stand and the pre-stacker. 
     
     
         8 . The efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 1 ,  2  or  6 , wherein the  1 # cooling bed and the  1 # inspection stand extend to the third factory span. 
     
     
         9 . A method for producing medium-heavy plates by using an efficient straight through medium-heavy plate production line of double rack and double shearing line according to  claim 1 , comprising the following steps:
 1) directly feeding a continuous casting slab online through a continuous casting rolling way to a heating furnace rolling way before a heating furnace at maximum temperature for deburring and weighting;   2) loading the weighted continuous casting slab into a heating furnace for heating according to the planned loading process;   3) after heating the continuous casting slab to a target temperature, feeding the obtained steel to a steel rolling and delivery rolling way in a main rolling line, to firstly perform surface treatment by using a high pressure water descaling machine, so as to remove iron oxide scale on the surface of the continuous casting slab;   4) feeding the continuous casting slab after high pressure water descaling to a fixed width press for online width adjustment, so as to achieve the desired width before arriving at a stand roller; then, at the time the continuous casting slab arrives at the stand roller, adjusting the plane shape, head shape, tail shape and edge shape of the continuous casting slab by the stand roller for to allow good precision of width dimension of steel plate in downstream processes;   5) feeding the continuous casting slab that is conveyed out of the stand roller to a four-roll roughing roller for intermediate blank rolling, so as to roll the continuous casting slab into a specified thickness and width, or in an urgent case, into a finished product by a single rack, wherein the steel plate is not subjected to widening rolling;   6) feeding the slab that has been subjected to roughing rolling to a four-roll finishing mill to roll the slab into the desired width and thickness of the steel plate according to the specified roller numbers, bite speed and reduction parameters, so as to obtain the desired plate shape and difference in the same plate, and achieve the final rolling temperature for the steel plate under different temperature control requirement;   7) after the rolling of the finished product is finished, passing the steel plate through an ACC accelerated cooling device according to the requirement on cooling control, wherein if there is a cooling requirement, performing online cooling according to the parameters such as cooling speed, flow and passing speed as modeled and specified, to achieve the target final cooling temperature, so as to improve the mechanical property of the steel plate; and if there is no cooling requirement, passing the steel plate directly through the ACC accelerated cooling device;   8) after passing the steel plate through the ACC accelerated cooling device, feeding the steel plate to a hot straightening machine by a straightening process with one pass so as to improve the plate shape, wherein if the shape of rolled plate is undesired, the number of the passes in the straightening process can be increased;   9) subjecting the steel plate that has been treated by the hot straightening machine to an intermediate process labeling at  1 # labeling device so as to facilitate the tracing of the intermediate process of the steel plate;   10) segmenting the labeled steel plate at a hot segmenting shear so as to meet the requirement on the maximum length for entering into a cooling bed, wherein the segmented steel plate can be cooled by selecting different cooling beds according to the stream flow condition; and the steel plate for straight-through processing can be directly fed into a shearing rolling way of the shearing line from the delivery rolling way, without entering into the cooling bed;   11) sending the cooled steel plate to one of the two inspection stands for inspection and delivering it to the shearing rolling way of the shearing line;   12) feeding the steel plate which has been passed through the inspection stand (the temperature has been reduced to be below 80° C.) to a flaw detector to perform flaw detecting operation according to the different requirements on flaw detecting, wherein the steel plate that needs no flaw detecting is passed directly through the flaw detector;   13) feeding the steel plate which has finished the flaw detecting operation to a crop shear for head and tail cutting, so as to cut a “tongue” part of the head, and segment for a length of over 30 m, wherein the segmentation length is adjusted according to the length of the rolling way; and wherein the steel plate segmentation is prepared and ready for later edge shearing; and if the tail shape of the steel plate is undesired, the tail cutting treatment must be performed;   14) feeding the steel plate which has been subjected to the head and tail cutting to a bilateral shear for cutting burrs on two sides of the steel plate, wherein the location of the movable shear of the bilateral shear is adjusted in advance according to the width of the finished product to be cut;   15) after cutting by the bilateral shear, subjecting the steel plate to sample jet printing at a labeling device, wherein if there is no sample of the steel plate, the labeling device is omitted;   16) after the steel plate is passed through the labeling device, feeding the steel plate to a cut-to-length shear to cut the steel plate into a length meeting the requirement of the final contract, and to perform sampling according to the requirement on sampling the steel plate, and sending the sampled big sample to a sample shear for the next processing and property testing;   17) after cutting the finished product of the steel plate, feeding it to an inkjet printer to perform jet printing on the finished product, so as to print contract information, type of steel, ship classification society logo and required information on flaw detecting onto the steel plate, wherein if the shape of the steel plate is undesired, only the plate number is printed, and the steel plate is later passed through a traverse stand for a cold correction printing; and if turnover is needed, the steel plate is traversed to a plate turnover machine for a turnover inspection; and   18) after finishing the jet printing, sending the steel plate to a final product inspection site for inspection, wherein if the steel plate has no problem after inspection, it is directly passed through a pre-stacker and enters into a library through the rolling way for stacking; and if the shape of the steel plate is undesired, it is passed through the traverse stand to enter into a cold straightening machine for shape correction, and labeling by a labeling device after correction; and, the labeled steel plate enters into a library of finished products through a delivery rolling way, and enters into a stacking location of the library of finished products for stacking through a collection stand for finished products according to the requirement on stacking, to wait to be shipped out of the factory.   
     
     
         10 . The method according to  claim 9 , wherein after step 5), if there is a requirement of temperature controlling and finish rolling on the slab, an intermediate cooling device is used to perform water spray cooling after rough rolling, wherein the parameters such as flow and speed can be calculated according to the cooling model to achieve the function of temperature control of slabs of different requirements, and part of the slab without temperature control requirement can be passed directly through the intermediate cooling device.