Short-process rolling method and system for bar stock

Abstract

This invention discloses a short-process bar rolling method and system. The method includes the following steps: S1, heating the billet in a heating furnace; S2, descaling with high-pressure water; S3, completing eight rolling passes in rolling zone one; S4, performing multiple-length segmentation with a first flying shear; S5, performing four rolling passes in rolling zone two; S6, performing multiple-length segmentation with a second flying shear; S7, performing diameter reduction rolling on the bar using a KOCKS mill; S8, a third flying shear; S9, water cooling; S10, cooling; S11, shearing the bar to length; S12, finishing and annealing; S13, magnetic flux leakage testing. This invention can meet the requirements for bar shape and size as well as the requirements for flaw detection, achieving integrated bar heating, controlled rolling and cooling, and flaw detection while saving space. This invention can reduce the number of traditional bar rolling passes, realizing short-process bar production with small space requirements, low power consumption, customization, greenness, and low carbon emissions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of steel metallurgy short process rolling, and particularly relates to a short process rolling method and system for bar. BACKGROUND

[0002] The steel industry is an important basic industry of the national economy, and the crude steel output of China has ranked first in the world for 27 consecutive years. The steel industry plays an important role in the regional economic and social development of China, is an important leading industry, and is also the main battlefield of industrial transformation and upgrading. As an important product of the steel industry, bar is widely used in the fields of construction, machinery, automobile, and shipbuilding, and is mainly used as various shafts, bolts, nuts, anchor chains, and spring materials.

[0003] The traditional production process of bar is as follows: smelting, continuous casting, heating, descaling, continuous rolling, flying shearing, water cooling, cold bed, cutting to size, finishing and annealing, and magnetic flux leakage detection. The production process is relatively long, and the land occupation area is large, which cannot meet the needs of short process, land saving, and energy saving and carbon reduction of the steel industry. SUMMARY

[0004] In order to solve the technical problems existing in the prior art, the present application provides a short process rolling method and system for bar, which can greatly save the rolling area space and save the total energy consumption of the rolling mill unit, realize small area, short process, and low energy consumption bar product rolling production, and promote the development of bar organization performance experimental research.

[0005] Specifically, the technical scheme of the present application is as follows:

[0006] The present application provides a short process rolling method for bar, which specifically comprises the following steps:

[0007] S1, heating the square billet by using a heating furnace: heating the square billet to a target rolling temperature by the heating furnace to improve the plastic deformation ability of the square billet;

[0008] S2, high-pressure water descaling: removing the iron oxide scale on the surface of the heated square billet by using high-pressure water impact;

[0009] S3, completing eight passes of rolling by using eight groups of rolling mills in the rolling area: combining the first three passes of rolling mill grooves to the first pass of rolling mill for the first pass of rolling, which specifically comprises: firstly rolling the steel billet by 65% to 70% reduction, then turning the steel billet by 90° and rolling by 80% to 85% reduction, and finally turning the steel billet by 90° and rolling by 100% reduction, after the first pass of rolling is completed, subsequent pass rolling is carried out, the distance between the first pass and the second pass is adjusted according to the length of the bar, and after eight passes of rolling, the square billet is rolled into a bar with a diameter of Φ60mm to Φ90mm;

[0010] S4, using the first flying shear to segment: using the first flying shear in the bar rolling production state to segment the bar;

[0011] S5, using four groups of rolling mill in the second rolling area to perform four-pass rolling: the bar enters the second rolling area and is rolled by means of four-pass rolling mill group, and the diameter of the bar is reduced;

[0012] S6, using the second flying shear to segment: using the second flying shear to segment the bar in the bar rolling production state;

[0013] S7, using two groups of KOCKS rolling mills in the second rolling area to reduce the diameter of the bar: two-pass KOCKS rolling mills are added to compress the diameter of the bar to Φ30mm-Φ60mm;

[0014] S8, using the third flying shear to segment: using the third flying shear to segment the bar in the bar rolling production state;

[0015] S9, water cooling the bar after rolling: water cooling the bar to control the surface temperature of the bar, improve the surface hardness of the bar, control the organization performance of the bar, make the core temperature pass to the surface of the bar, and realize the self-tempering of the surface of the bar;

[0016] S10, using a cooling bed to cool the bar: cooling the bar of the size segmented by the flying shear;

[0017] S11, changing the length of the bar by sizing;

[0018] S12, finishing and annealing: annealing the bar by using an annealing device.

[0019] Preferably, temperature control is required in the above steps, and the specific temperature control is as follows: the furnace outlet temperature of the heating furnace is 1200℃±30℃, the high-pressure water descaling enters the first rolling area, and the initial rolling temperature is 1100±30℃, if the temperature of the billet after rolling in the first rolling area is lower than 1200℃±30℃, the billet needs to be reheated to 1200℃±30℃ in the heating furnace, and then enter the second rolling area for finish rolling, the water cooling temperature is 800℃±20℃, the cooling bed temperature is 750℃±20℃, and the annealing temperature is 770℃±20℃.

[0020] Preferably, the temperature of the billet needs to be controlled during the heating process, and the core-surface temperature difference of the billet is controlled within ±10℃.

[0021] Preferably, the high-pressure water descaling adopts a small water quantity and a large pressure to remove the oxide layer on the surface of the billet.

[0022] Preferably, step S3 specifically includes the following sub-steps:

[0023] S31, the first three passes hole type is combined to the first pass rolling mill, and reciprocating rolling is carried out, after the first pass rolling is completed at 65%~70% of the first pass rolling, the billet is turned over by 90°, the second pass rolling is carried out at 80%~85% of the second pass rolling, and the billet is turned over by 90° again, the third pass rolling is realized at 100% of the third pass rolling, and thus the first pass rolling of the billet is completed;

[0024] S32, after the first pass rolling is completed, the second pass rolling mill is entered, and the distance between the first mill stand and the second pass rolling mill stand needs to be determined in combination with the length of the rod after the third pass rolling is completed.

[0025] Preferably, the rod diameter is compressed to Φ30mm~Φ60mm by the two-pass KOCKS rolling mill in step S7.

[0026] Preferably, the method further comprises step S13, magnetic flux leakage flaw detection: the surface quality of the formed rod is detected by the magnetic flux leakage detection method.

[0027] On the other hand, the present application also provides a short process rod rolling system, which comprises a heating furnace, a high-pressure water descaling box, a rolling area, a rolling area, a water cooling device, a cooling bed, a cutting device, an annealing device and a magnetic flux leakage flaw detection device, the rolling area comprises eight groups of rolling mills and a first flying shear, the rolling area comprises four groups of rolling mills, a second flying shear, two groups of KOCKS rolling mills and a third flying shear.

[0028] The heating furnace is a pusher heating furnace, which comprises a plurality of burners, a blower, an induced draft fan and a pusher, the heating furnace heats the billet to the austenite temperature region, realizes complete austenitization of the billet, and can heat the billet to 1200℃, the maximum output is 2.2t / h, the maximum gas consumption is 76.3m 3 / h; the maximum combustion air volume is 870m 3 / h; the maximum flue gas generation amount is 950m 3 / h

[0029] Preferably, the heating and rolling square billet steel is an alloy steel, and the square billet side length is

[0030] 150mm~160mm and 220mm~240mm.

[0031] Preferably, the finishing and annealing device is an electric heating furnace, and the highest furnace temperature is 900℃, and the heating power is 220KW.

[0032] Compared with the prior art, the present application has the following effects:

[0033] (1) The bar rolling method of the present invention is based on the traditional industrial fourteen-pass rolling process and reengineers the process. The rolling mill pass of the first three passes is merged into the first pass rolling mill. Combining forward and reverse rolling methods, and with billet flipping, a single-pass rolling process replaces the traditional three-pass rolling process. This significantly saves the rolling mill arrangement space and optimizes the rolling area layout, realizing a complex rolling process in a small area. By adopting a zoned rolling method, steel billets of different specifications are rolled into large-span bars with diameters of Φ30mm to Φ90mm, achieving efficient bar rolling. By adopting a low-speed rolling method, the total power consumption of the motors when the rolling mills in each pass are running simultaneously is reduced, meeting the requirement of less than 6000kw·h, thus achieving low-energy rolling.

[0034] (2) This invention divides the entire rolling area into two parallel rolling areas, namely Rolling Zone 1 and Rolling Zone 2. Rolling Zone 1 contains eight rolling mills and a first flying shear. In this area, billet specifications of 220mm to 240mm and diameter of Φ60mm to Φ90mm bars can be rolled. The first flying shear divides the Φ60mm to Φ90mm bars into multiple-length segments to complete the rolling of large-diameter bars. To produce bars with a diameter of Φ30mm to Φ60mm, heated billets of 150mm to 160mm are first rolled in Rolling Zone 1. The rough-rolled bars are then fed into Rolling Zone 2 via roller conveyors. Rolling Zone 2 contains four finishing mills and two KOCKS mills. After rolling, the bars are divided into multiple-length segments by the flying shear, and then subjected to post-rolling water piercing, cold piercing, and annealing processes to achieve the rolling of small-diameter bars.

[0035] (3) The present invention sets up a descaling device before rough rolling. The descaling device adopts a small water volume and high pressure design method, which can spray high pressure water to remove iron oxide scale on the surface of steel billet, reduce the temperature drop of steel billet, and save energy.

[0036] (4) The present invention uses a pusher heating furnace to heat the billet, which meets the needs of small batch production of bars, saves energy, and adds post-rolling water quenching, cooling bed, finishing and annealing processes to achieve control of bar shape and properties.

[0037] (5) This invention aims to achieve bar rolling production in a small area with low energy consumption, which is of great significance in bar production line configuration, small batch, customized and low-carbon production. Furthermore, it establishes an advanced rolling device for this method to realize quantitative discontinuous production of bars, reduce resource waste, improve production efficiency, and significantly save metal resource costs. Attached Figure Description

[0038] Figure 1 This is a traditional bar rolling process;

[0039] Figure 2 This invention relates to a short-process rolling technology and method for bar stock;

[0040] Figure 3 A schematic diagram of a short process rolling process equipment for a bar of the present application;

[0041] Figure 4 A schematic diagram of a rolling zone pass optimization of the present application;

[0042] Figure 5 A schematic diagram of the first pass reciprocating rolling of the rolling zone of the present application. DETAILED DESCRIPTION

[0043] Hereinafter, the embodiments of the present application will be described with reference to the accompanying drawings.

[0044] The present application is based on the process reengineering of the traditional industrial fourteen-pass rolling process, the first three-pass rolling mill pass is combined to the first-pass rolling mill, combined with the forward rolling and reverse rolling method, and accompanied by the billet overturning, the one-pass rolling replaces the traditional three-pass rolling, greatly saves the rolling mill arrangement space and optimizes the rolling zone arrangement method, realizes the small area complex rolling process. The partition rolling method is adopted to roll different specifications of billets to large span bars with a diameter of Φ30mm-Φ90mm, realizing the efficient rolling of bars. The low speed rolling method is adopted to reduce the total power consumption of the motor when each pass rolling mill is running at the same time, meeting the requirement of less than 6000kw·h power, realizing low energy consumption rolling.

[0045] The short process rolling method of the present application will be further described below with the help of specific embodiments, the equipment process flow thereof is shown in Figure 2 The rolling zone includes eight groups of rolling mills and a first flying shear, the rolling zone two includes four groups of rolling mills, a second flying shear, two groups of KOCKS rolling mills and a third flying shear. The eight groups of rolling mills of the rolling zone one and the four groups of rolling mills of the rolling zone two are arranged in the way of alternating forward rolling and reverse rolling.

[0046] Based on the above equipment, the specific process flow of the present application is as follows: pusher furnace heating→high pressure water descaling→rolling zone one→first flying shear→rolling zone two→KOCKS rolling mill→third flying shear→water cooling→cold bed→shearing gauge→finishing and annealing→magnetic flux leakage flaw detection.

[0047] In the specific embodiment, the heating furnace is a pusher type heating furnace, the bottom of the furnace body is a corundum brick paving structure, the billets are arranged in two rows in the furnace, the pusher type advances, and the steel can be discharged in a natural sliding or a steel discharge machine discharging manner; the heating furnace adopts natural gas combustion heating, the reversing combustion way, the heating furnace is provided with multiple burners, blowers, induced draft fans and pushers. The heating furnace can heat the billet to 1200℃, the maximum output is 2.2t / h, the maximum gas consumption is 76.3m3 / h; maximum combustion air amount 870 m 3 / h; maximum flue gas generation amount 950 m 3 / h.

[0048] The water cooling device adopts a single-line water cooling device, the annealing process adopts an electric heating furnace, the roller bottom type furnace bottom, and the maximum furnace temperature is 900 DEG C, and the heating power is 220 KW.

[0049] Based on the above equipment and process, specifically the rolling method specifically includes the following steps:

[0050] S1, heating the square billet by using the heating furnace: the square billet is heated to the target rolling temperature by the heating furnace, the plastic deformation ability of the square billet is improved, the square billet is heated by using the pusher type heating furnace, the uniformity of the square billet heating temperature can be improved under the condition of considering the limited floor area, and the stable initial temperature requirement for subsequent rolling deformation is provided.

[0051] S2, high-pressure water descaling by using the high-pressure descaling box: the square billet after heating by the heating furnace is oxidized due to the oxidizing atmosphere in the furnace, the surface of the steel billet is oxidized, there is an oxide layer, the oxide layer is pressed into the square billet during the subsequent rolling deformation process, surface defects such as pits and rough surface are generated, and the product quality of the bar is seriously affected. Therefore, the high-pressure water impact is used to remove the iron scale on the surface of the steel billet, and the surface quality of the steel billet before entering the rolling mill is improved.

[0052] S3, eight passes of rough rolling by using eight groups of rolling mills in the first rolling area: there are eight passes of rolling mills in this rolling area, and the square billet with a size of 220mm-240mm is rolled into a bar with a diameter of Φ60mm-Φ90mm. The first three passes of rolling mill pass are combined into the first pass of rolling to perform the first pass of rolling. The specific process of the first pass of rolling is as follows: first, the steel billet is rolled by 65%-70% reduction, then the steel billet is turned over by 90°, and the steel billet is rolled by 80%-85% reduction in reverse. Finally, the steel billet is turned over by 90°, and the steel billet is rolled by 100% reduction. After the first pass of rolling is completed, subsequent passes of rolling are performed. The distance between the first pass and the second pass of rolling mill is related to the length of the bar.

[0053] S4, segmenting the rough-rolled bar by using the first flying shear: after completing eight passes of rolling, the first flying shear is used to segment the bar in the bar rolling production state, and thus the bar with a diameter of Φ60mm-Φ90mm is completed.

[0054] S5, finishing rolling by using four groups of rolling mills in the second rolling area: in order to realize the rolling production of the bar with a diameter of Φ30mm-Φ60mm, the square billet with a size of 150mm-160mm is processed and manufactured after steps S1, S2, S3 and S4, and then enters the second rolling area. The second rolling area is provided with four passes of rolling mill units, and can further compress the diameter of the square billet.

[0055] S6, using the second flying shear to realize the doubling segmentation of the bar: after completing four passes of rolling, the second flying shear is used to segment the bar in the bar rolling production state.

[0056] S7, the reducing mill set: in order to compress the diameter of the bar to Φ30mm-Φ60mm, two passes of KOCKS rolling mill are added, the distance between the KOCKS rolling mill racks is small, the longitudinal tension is small, the equipment occupies a small area, which is beneficial to the rolling deformation of high alloy steel which is difficult to deform, the size tolerance of the rolled piece is small, and the surface quality and size precision of the bar can be further improved.

[0057] S8, using the third flying shear to realize the doubling segmentation of the bar: the third flying shear is used to segment the bar in the bar rolling production state.

[0058] S9, using water cooling equipment to cool the bar: control the surface temperature of the bar, improve the surface hardness of the bar, control the organization performance of the bar, avoid the growth of organization grain, the core temperature of the bar is transmitted to the surface, and the self tempering of the bar surface is realized.

[0059] S10, using the cooling bed to cool the bar: the bar in the size of the flying shear is cooled to avoid irregular bending of the billet.

[0060] S11, using the shear to change the length of the bar to make the length of the bar meet the requirements.

[0061] S12, using annealing device for finishing and annealing: reducing the hardness of the bar, eliminating the residual stress of the bar, stabilizing the size of the bar, reducing the crack, refining the organization grain, eliminating the organization defects, realizing the stable control of the organization performance of the bar.

[0062] S13, magnetic flux leakage detection: in order to ensure the quality of the bar, after annealing, the surface quality of the formed bar needs to be detected by magnetic flux leakage detection method to avoid the existence of surface defects.

[0063] In the above production process, the temperature of each process needs to be controlled, and the specific control temperature is as follows: the furnace temperature is 1200℃±30℃, the high-pressure water descaling enters the rough rolling mill set, the initial rolling temperature is 1100±30℃, the billet needs to be reheated to 1200℃±30℃ in the heating furnace when the temperature in the rolling area is low, then enter the finishing rolling area, the water cooling temperature is 800℃±20℃, the cooling bed temperature is 750℃±20℃, and the annealing temperature is 770℃±20℃.

[0064] Figure 1 The traditional processing process diagram of the bar is, Figure 3The schematic diagram of the reformed post-equipment arrangement of the bar rolling process is shown, the billet is heated by the pusher type heating furnace, the surface iron scale is removed by the descaling machine, the diameter of the bar is Φ60mm-Φ90mm, only the bar needs to enter the rolling area one for rolling and flying shearing, the pass optimization method of the rolling area one is shown as Figure 4 , the rolling process is shown as Figure 5 , the diameter of the bar is Φ30mm-Φ60mm, after the rough rolling of the rolling area one, the bar still needs to enter the rolling area two for processing, after the rolling of the two KOCKS rolling mills, the water cooling, the cooling bed cooling, the cutting to size, the finishing and annealing process and the final magnetic flux leakage detection are carried out, and the surface quality of the bar is ensured to be good.

[0065] The whole rolling area is divided into two parallel rolling areas, which are the rolling area one and the rolling area two. There are eight passes of rolling mills and a No. 1 flying shear machine in the rolling area one, the square billet with the specification of 220mm-240mm can be rolled into the bar with the diameter of Φ60mm-Φ90mm in the area, the No. 1 flying shear machine divides the bar with the diameter of Φ60mm-Φ90mm into multiple sections, so as to complete the rolling of the large diameter bar. The square billet with the specification of 150mm-160mm after heating is first rolled in the rolling area one to produce the bar with the diameter of Φ30mm-Φ60mm, the rolled bar is sent to the rolling area two through the roller way, the rolling area two stores four passes of finishing rolling mills and two passes of KOCKS rolling mills, after the rolling, the bar is divided into multiple sections by the flying shear machine, and then the water cooling, the cold water cooling and the annealing process are carried out, so as to realize the rolling of the small diameter bar.

[0066] The working of the present application is further described in combination with the specific embodiments as follows: Specific embodiment 1:

[0068] The bar with a diameter of Φ60mm-Φ90mm is rolled. First, the alloy steel billet with a size of 220mm-240mm is heated in a pusher-type heating furnace, the billet is heated to 1200℃±30℃, the billet is sent to a descaler through a roller, the high-pressure water jet is used to remove the scale on the surface of the billet, then the roller is used to send the billet with the surface treatment completed to a rolling area for rolling, the rolling reduction is 70% in the first pass, the initial rolling temperature is 1100℃±30℃, then the billet is turned over by 90°, the reverse rolling with a reduction of 85% is performed, finally, the billet is turned over by 90° again for forward rolling, the bar rolled in the first pass is sent to the rolling area for subsequent seven passes of rolling, the formed bar is segmented by a flying shear device. The bar with a diameter of Φ60mm-Φ90mm only needs to be processed in the rolling area, and does not need to be finished in the second rolling area to meet the requirements. The size and organizational properties of the bar produced are controlled through the flying shear, post-rolling water cooling and cooling bed process, after the cooling bed, the bar is cut to size, the size of the bar is determined, then annealing treatment is performed to refine the grains and eliminate the internal residual stress of the bar, finally, the magnetic flux leakage detection is performed to ensure that the surface quality of the bar product is optimized.

[0069] In the specific generation, rough rolling only in the first rolling area or rough rolling in the first rolling area and then entering the second rolling area for finish rolling can be selected according to the needs, which can be selected according to the size requirements of the bar. Specific embodiment 2:

[0071] The bar with a diameter of Φ30mm-Φ60mm is rolled. First, the alloy steel billet with a size of 150mm-160mm is heated in a pusher-type heating furnace, the billet is heated to 1200℃±30℃, the billet is sent to a descaler through a roller, the high-pressure water jet is used to remove the scale on the surface of the billet, then the roller is used to send the billet with the surface treatment completed to a rolling area for rolling, the rolling reduction is 65% in the first pass, the initial rolling temperature is 1100℃±30℃, then the billet is turned over by 90°, the reverse rolling with a reduction of 80% is performed, finally, the billet is turned over by 90° again for forward rolling, the bar rolled in the first pass is sent to the rolling area for subsequent seven passes of rolling, the diameter of the bar after rolling needs to be further compressed and finished, then the roller is used to send the bar after rough rolling to the second rolling area for four passes of rolling mill rolling and two KOCKS rolling mills for finish rolling, the diameter of the bar after finish rolling meets the production requirements, then the size and organizational properties of the bar produced are controlled through the flying shear, post-rolling water cooling and cooling bed process, after the cooling bed, the bar is cut to size, the size of the bar is determined, then annealing treatment is performed to refine the grains and eliminate the internal residual stress of the bar, finally, the magnetic flux leakage detection is performed to ensure that the surface quality of the bar product is optimized.

[0072] The above described embodiments are only to illustrate the preferred embodiments of the present application, and are not intended to limit the scope of the present application. Any modification and improvement of the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application.

Claims

1. A short flow process for rolling a bar, characterized in that: It specifically includes the following steps: S1, heating the billet with a heating furnace: the billet is heated to the target rolling temperature by the heating furnace to improve the plastic deformation ability of the billet; S2, high-pressure water descaling: the high-pressure water impact is used to remove the surface scale of the heated billet; S3, eight passes of rolling are completed by using eight groups of rolling mills in the rolling area one: the first three passes of rolling mill grooves are combined to the first pass of rolling mill for the first pass of rolling, which specifically includes: first, the steel billet is rolled by 65%~70% reduction, then the steel billet is turned over by 90° and rolled by 80%~85% reduction, and finally the steel billet is turned over by 90° and rolled by 100% reduction, after the first pass of rolling is completed, the subsequent pass of rolling is carried out, the distance between the first pass and the second pass is adjusted according to the length of the bar, and after eight passes of rolling, the billet is rolled into a bar with a diameter of Φ60mm~Φ90mm; S4, using the first flying shear to segment by multiple lengths: using the first flying shear to segment the bar by multiple lengths in the bar rolling production state, completing the rolling of the bar with a diameter of Φ60mm~Φ90mm; S5, using four groups of rolling mills in the rolling area two to carry out four passes of rolling: the bar enters the rolling area two and is rolled by means of four passes of rolling mill group to reduce the diameter of the bar; S6, using the second flying shear to segment by multiple lengths: using the second flying shear to segment the bar by multiple lengths in the bar rolling production state; S7, using two groups of KOCKS rolling mills in the rolling area two to reduce the diameter of the bar; S8, using the third flying shear to segment by multiple lengths: using the third flying shear to segment the bar by multiple lengths in the bar rolling production state; S9, water cooling the rolled bar: water cooling the bar to control the surface temperature of the bar, improve the surface hardness of the bar, control the organization performance of the bar, make the core temperature of the bar pass to the surface of the bar, and realize the self-tempering of the surface of the bar; S10, cooling the bar by using a cooling bed: cooling the bar segmented by the flying shear; S11, changing the length of the bar by trimming; S12, finishing and annealing: annealing the bar by using an annealing device; Temperature control is required in the above steps, and the specific temperature control is as follows: the furnace temperature of the heating furnace is 1200℃±30℃, the billet enters the rolling area one after high-pressure water descaling, the initial rolling temperature is 1100±30℃, if the temperature of the billet after rolling in the rolling area one is lower than 1200℃±30℃, the billet needs to be reheated to 1200℃±30℃ in the heating furnace, then enter the rolling area two for finish rolling, the water cooling temperature is 800℃±20℃, the cooling bed temperature is 750℃±20℃, and the annealing temperature is 770℃±20℃.

2. The bar short-stroke rolling method according to claim 1, characterized in that: The temperature of the steel billet needs to be controlled during heating, and the core-surface temperature difference of the steel billet is controlled within ±10℃.

3. The bar short-stroke rolling method according to claim 1, characterized in that: The high-pressure water descaling adopts the form of small water quantity and high pressure to remove the oxide layer on the surface of the billet.

4. The bar short-stroke rolling method according to claim 1, characterized by: Step S3 specifically includes the following sub-steps: S31, the first three passes hole type is combined to the first pass rolling mill, and reciprocating rolling is carried out; after the first pass rolling is completed with a pass reduction of 70%, the billet is turned over by 90°, the second pass reduction of 85% is carried out, the billet is turned over by 90° again, the third pass reduction of 100% is realized, and thus the first pass rolling of the billet is completed; S32, after the first pass rolling is completed, the billet enters the second pass rolling mill, and the distance between the first rolling mill and the second pass rolling mill is combined to determine the length of the third pass rod after the first pass rolling.

5. The bar short-stroke rolling method according to claim 1, characterized by: In step S7, two pass KOCKS rolling mills are arranged to compress the rod diameter to Φ30mm~Φ60mm.

6. The bar short-stroke rolling method according to claim 1, characterized by: It also includes step S13, magnetic flux leakage detection: the surface quality of the formed rod is detected by the magnetic flux leakage detection method.

7. A bar short flow rolling system for use in the bar short flow rolling method according to claim 1, characterized by: It includes a heating furnace, a high-pressure water descaling box, a first rolling area, a second rolling area, a water cooling device, a cooling bed, a cutting device, an annealing device and a magnetic flux leakage detection device, the first rolling area includes eight rolling mills and a first flying shear, the second rolling area includes four rolling mills, a second flying shear, two KOCKS rolling mills and a third flying shear; The heating furnace is a pusher heating furnace, which comprises a plurality of burners, a blower, an induced draft fan and a pusher, the heating furnace heats the billet to the austenite temperature region, realizes complete austenitization of the billet, the heating furnace can heat the billet to 1200 DEG C, the output is 2.2 t / h, the gas consumption is 76.3 m 3 / h; the maximum amount of combustion air is 870 m 3 / h; the maximum amount of flue gas is 950 m 3 / h.

8. The bar short-stroke rolling system according to claim 7, characterized in that: The heating and rolling square billet steel is alloy steel, and the square billet side length is 150mm~160mm and 220mm~240mm.

9. The bar mini mill system of claim 7, wherein: The finishing and annealing device is an electric heating furnace, the furnace temperature is less than or equal to 900℃, and the heating power is 220KW.

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