Emergency production method for reinforcing steel bars with specification of phi 50

Abstract

The invention discloses an emergency production method for reinforcing steel bars with the specification of phi 50. The emergency production method comprises the following steps that S1, the length and the section of a needed steel billet are calculated according to the available length of a large cooling bed and the size of a heating furnace; s2, steel billets enter a heating furnace in a two-side material distribution mode; s3, the steel billets sequentially pass through the roughing mill unit, the intermediate mill unit and the finishing mill unit to form rolled pieces, and rolling line hole patterns are redesigned and matched; and S4, the rolled piece is taken out of the rolling mill, clamped by the pinch roll for a certain time and fed to a cooling bed. The method has the advantages that capital investment and time occupation can be reduced by changing the size of the steel billet, reducing the length of the steel billet and canceling shearing of a double-length shear, and meanwhile it can be guaranteed that the steel bars of the phi 50 specification can be produced without transformation of an existing production line through hole pattern optimization.

Description

Technical Field

[0001] The invention relates to the technical field of steel bar production, and in particular to an emergency production method for steel bars with a specification of φ50. Background Art

[0002] At present, with the development of the market and the changes in the application of steel bars, nuclear power projects, tunnel engineering projects, cross-sea bridge projects, etc. have a certain demand for φ50 steel bars. Domestic bar production lines, due to the small number of φ50 orders, basically do not consider this specification when the production line is put into operation, and few can roll φ50 steel bars. The main limiting factor is that the shearing capacity of the double-length shear is insufficient, which cannot be sheared normally. The transformation of the double-length shear requires a large amount of capital and takes a long time. The equipment and civil engineering take about half a year, with an investment of more than 8 million, and the transformation cost is relatively high. In recent years, the production of bars put into production and under construction has a large heating furnace and a long production line. If there is not enough force to move forward, the rolled piece will stay in the roller. Summary of the invention

[0003] The purpose of the present invention is to provide an emergency production method for φ50 specification steel bars. By changing the size of the steel billet, reducing the length of the steel billet, and canceling the shearing with double-length shears, the capital investment and time occupation can be reduced. At the same time, through the optimization of the hole type, it can ensure that the existing production line can produce φ50 specification steel bars without modification.

[0004] The above technical objectives of the present invention are achieved through the following technical solutions:

[0005] A method for emergency production of φ50 steel bars, characterized in that it comprises the following steps:

[0006] S1, calculate the required billet length and cross-section according to the available length of the large cooling bed and the size of the heating furnace;

[0007] S2, the billet enters the heating furnace by means of two-side feeding;

[0008] S3, the steel billet is successively rolled through the roughing mill, the intermediate rolling mill and the finishing mill to form a rolled piece, and the rolling line pass is redesigned and matched;

[0009] S4, the rolled piece is clamped by the pinch rollers after leaving the rolling mill for a certain period of time and then put on the cooling bed.

[0010] Preferably, in S1, firstly according to the available length L of the large cooling bed 1 The calculation of the required billet weight M is as shown in formula (1):

[0011]

[0012] Where m is the weight of φ50 steel bar per meter, 15.42kg / m; c is the negative tolerance, 1.5%; and T is the yield rate, 97.5%;

[0013] Then, the required billet weight M is calculated to construct the required billet weight M, the required billet cross-sectional area S, and the length L. 2 The specific formula is shown in formula (2):

[0014] M=S*ρ*L 2 (2)

[0015] Where ρ is the density of the steel billet 7.85 g / cm 3 .

[0016] Preferably, the required length of the steel billet in S1 satisfies the following conditions: the distance between the steel billet and the static beam is 40 cm, and the other end of the steel billet does not scrape the moving beam.

[0017] Preferably, the method of distributing the billets on both sides of the heating furnace in S2 is as follows: the tail of the billet on the non-rolling mill side is positioned in the middle of the first cantilever roller head entering the furnace, 40 cm away from the side furnace wall of the rolling mill; the head of the billet on the rolling mill side is positioned in the middle of the fourth and fifth cantilever roller heads at the feeding end, and the head of the billet is 40 cm away from the furnace wall.

[0018] Preferably, the finishing mill group in S3 includes a first finishing mill group and a second finishing mill group in sequence, the roughing mill group includes 6 rolling mills, the intermediate rolling mill group includes 4 rolling mills, the first finishing mill group includes 6 rolling mills, and the second finishing mill group includes 4 rolling mills.

[0019] Preferably, the tail frame of the intermediate rolling mill group is 36 m away from the head frame of the first finishing mill group, and the tail frame of the first finishing mill group is 70 m away from the head frame of the second finishing mill group.

[0020] Preferably, the rolling hole profiles starting from the last stand in the S3 rough rolling mill group are sequentially set to: a first round hole profile, a first elliptical hole profile, a second round hole profile, a third round hole profile, a fourth round hole profile, a second elliptical hole profile and a fifth round hole profile.

[0021] Preferably, the first round hole hole profile has a hole slot width of 90 mm, a slot corner radius of 8 mm, a groove bottom radius of 41 mm, a roll gap of 12 mm, a side wall inclination angle of 35°, and a hole profile height of 81 mm; the first elliptical hole profile has a hole profile height of 48 mm, a slot width of 111 mm, a slot corner radius of 5 mm, a groove bottom radius of 90 mm, and a roll gap of 10 mm; the second round hole hole profile, the third round hole hole profile, and the fourth round hole hole profile are of the same size, and the hole slot width is 66 mm. The slot corner radius is 6mm, the slot bottom radius is 31mm, the roll gap is 10mm, the side wall inclination angle is 33°, and the hole height is 61mm. The hole height of the second elliptical hole is 40mm, the slot width is 85mm, the slot corner radius is 5mm, the slot bottom radius is 65mm, and the roll gap is 8mm. The hole slot width of the fifth circular hole is 54mm, the slot corner radius is 5mm, the slot bottom radius is 25mm, the roll gap is 8mm, the side wall inclination angle is 35°, and the hole height is 49mm.

[0022] Preferably, the calculation formula of the delay time t in S4 is as shown in formula (3):

[0023]

[0024] Where L 3 is the distance between the finished product rack and the pinch roller, V is the speed of the finished product rack, t 设 The preset delay time is 0.3s.

[0025] In summary, the beneficial effects of the present invention are that by changing the size of the steel billet, reducing the length of the steel billet, and eliminating the shearing with double-length shears, the capital investment and time occupation can be reduced. At the same time, through the optimization of the hole type, it can ensure that the existing production line can produce φ50 specification steel bars without modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of the first circular hole type in the present invention;

[0027] Figure 2 It is a schematic structural diagram of the first elliptical hole type in the present invention.

[0028] Figure 3 It is a schematic diagram of the structures of the second circular hole shape, the third circular hole shape and the fourth circular hole shape in the present invention;

[0029] Figure 4 It is a schematic structural diagram of the second elliptical hole type in the present invention;

[0030] Figure 5 It is a schematic structural diagram of the fifth circular hole type in the present invention. DETAILED DESCRIPTION

[0031] The specific implementation manner of the present invention is further described below in conjunction with the accompanying drawings, and this embodiment does not constitute a limitation of the present invention.

[0032] A method for emergency production of φ50 steel bars, comprising the following steps:

[0033] S1, calculate the required billet length and cross-section based on the available length of the large cooling bed and the size of the heating furnace.

[0034] S2, the billet enters the heating furnace by means of two-sided feeding.

[0035] S3, the steel billet passes through the rough rolling mill, intermediate rolling mill and finishing rolling mill in sequence to form rolled products, and the rolling line pass profile is redesigned and matched.

[0036] S4, the rolled piece is clamped by the pinch rollers after leaving the rolling mill for a certain period of time and then put on the cooling bed.

[0037] In S1, the available length L of the large cooling bed is firstly calculated. 1 The calculation of the required billet weight M is as shown in formula (1):

[0038]

[0039] Among them, m is the weight of φ50 specification steel bar per meter 15.42kg / m, c is the negative tolerance 1.5%, and T is the yield rate 97.5%.

[0040] Then, the required billet weight M is calculated to construct the required billet weight M, the required billet cross-sectional area S, and the length L. 2 The specific formula is shown in formula (2):

[0041] M=S*ρ*L 2 (2)

[0042] Where ρ is the density of the steel billet, 7.85 g / cm 3 .

[0043] The required billet length in S1 satisfies the following conditions: the distance between the billet and the static beam is 40 cm near the rolling mill side, and the other end of the billet does not scrape the moving beam.

[0044] The specific method of distributing the billets on both sides of the heating furnace in S2 is as follows: the tail of the billet on the non-rolling mill side is positioned in the middle of the first cantilever roller head entering the furnace, 40 cm away from the side furnace wall of the rolling mill; the head of the billet on the rolling mill side is positioned in the middle of the fourth and fifth cantilever roller heads at the feeding end, and the head of the billet is 40 cm away from the furnace wall. This distribution method can ensure that the water beam in the furnace is evenly stressed, and the head and tail ends of the billet will not scratch the furnace wall and water beam during the stepping process, causing equipment damage, deviation and billet flipping, thereby causing major equipment accidents.

[0045] The finishing mill group in S3 includes the first finishing mill group and the second finishing mill group in sequence, the roughing mill group includes 6 rolling mills, the intermediate rolling mill group includes 4 rolling mills, the first finishing mill group includes 6 rolling mills, and the second finishing mill group includes 4 rolling mills.

[0046] The tail frame of the intermediate rolling mill is 36m away from the head frame of the first finishing mill, and the tail frame of the first finishing mill is 70m away from the head frame of the second finishing mill.

[0047] like Figures 1 to 5 As shown, the rolling hole types of the last stand in the S3 medium roughing mill group are set in sequence as follows: the first round hole type, the first elliptical hole type, the second round hole type, the third round hole type, the fourth round hole type, the second elliptical hole type and the fifth round hole type. The second round hole type, the third round hole type and the fourth round hole type are based on the principle of equal second flow rate, and the hole types of the three stands are the same. The function of the latter two stands is not to change the material size and to clamp and convey. Since the second flow rate is the same, the linear speeds of the three rolling mills should be equal. Due to different speed ratios, the rotation speeds of the corresponding rolling mills need to be reset.

[0048] The first round hole hole type has a hole slot width of 90mm, a slot corner radius of 8mm, a groove bottom radius of 41mm, a roll gap of 12mm, a side wall inclination angle of 35°, and a hole height of 81mm. The first elliptical hole type has a hole height of 48mm, a slot width of 111mm, a slot corner radius of 5mm, a groove bottom radius of 90mm, and a roll gap of 10mm. The second round hole hole type, the third round hole hole type, and the fourth round hole hole type have the same size, all of which have a hole slot width of 66mm and a slot corner radius of 90mm. The corner radius is 6mm, the groove bottom radius is 31mm, the roll gap is 10mm, the side wall inclination angle is 33°, and the hole height is 61mm. The hole height of the second elliptical hole is 40mm, the slot width is 85mm, the slot corner radius is 5mm, the groove bottom radius is 65mm, and the roll gap is 8mm. The hole slot width of the fifth circular hole is 54mm, the slot corner radius is 5mm, the groove bottom radius is 25mm, the roll gap is 8mm, the side wall inclination angle is 35°, and the hole height is 49mm.

[0049] The calculation formula of the delay time t in S4 is shown in formula (3):

[0050]

[0051] Where L 3 is the distance between the finished product rack and the pinch roller, V is the speed of the finished product rack, t 设 The preset delay time is 0.3s. The artificially set delay time can prevent the pinch rollers from clamping in advance and the material head from not passing the pinch rollers.

[0052] The beneficial effects of the present invention are that by changing the size of the steel billet, reducing the length of the steel billet, and eliminating the shearing with double-length shears, the capital investment and time occupation can be reduced. At the same time, through the optimization of the hole type, it can be ensured that the existing production line can produce φ50 specification steel bars without modification.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be deemed to fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for emergency production of φ50 steel bars, characterized in that: The steps include: S1, calculate the required billet length and cross-section according to the available length of the large cooling bed and the size of the heating furnace; S2, the billet enters the heating furnace by means of two-side feeding; S3, the steel billet is successively rolled through the roughing mill, the intermediate rolling mill and the finishing mill to form a rolled piece, and the rolling line pass is redesigned and matched; S4, the rolled piece is clamped by the pinch rollers after leaving the rolling mill for a certain period of time and then put on the cooling bed.

2. The method for emergency production of φ50 steel bars according to claim 1 is characterized in that: In S1, the required billet weight M is first calculated according to the available length L1 of the large cooling bed. The specific formula is shown in formula (1): Where m is the weight of φ50 steel bar per meter, 15.42kg / m; c is the negative tolerance, 1.5%; and T is the yield rate, 97.5%; Then, the relationship function between the required billet weight M and the required billet cross-sectional area S and length L2 is constructed by calculating the required billet weight M. The specific formula is shown in formula (2): M=S*ρ*L2 (2) Where ρ is the density of the steel billet 7.85 g / cm 3 .

3. The method for emergency production of φ50 steel bars according to claim 1 is characterized in that: The required length of the steel billet in S1 satisfies the following conditions: the distance between the steel billet and the static beam is 40 cm, and the other end of the steel billet does not scrape the moving beam.

4. The method for emergency production of φ50 steel bars according to claim 1 is characterized in that: The method of distributing the billets on both sides of the heating furnace in S2 is specifically as follows: the tail of the billet on the non-rolling mill side is positioned in the middle of the first cantilever roller head entering the furnace, 40 cm away from the side furnace wall of the rolling mill; the head of the billet on the rolling mill side is positioned in the middle of the fourth and fifth cantilever roller heads at the feeding end, and the head of the billet is 40 cm away from the furnace wall.

5. The method for emergency production of φ50 steel bars according to claim 1 is characterized in that: The finishing mill group in S3 includes a first finishing mill group and a second finishing mill group in sequence, the roughing mill group includes 6 rolling mills, the intermediate rolling mill group includes 4 rolling mills, the first finishing mill group includes 6 rolling mills, and the second finishing mill group includes 4 rolling mills.

6. The method for emergency production of φ50 steel bars according to claim 5 is characterized in that: The distance between the tail frame of the intermediate rolling mill group and the head frame of the first finishing mill group is 36 m, and the distance between the tail frame of the first finishing mill group and the head frame of the second finishing mill group is 70 m.

7. The method for emergency production of φ50 steel bars according to claim 1 is characterized in that: The rolling hole profiles of the last stand in the S3 rough rolling mill group are sequentially set to: the first round hole profile, the first elliptical hole profile, the second round hole profile, the third round hole profile, the fourth round hole profile, the second elliptical hole profile and the fifth round hole profile.

8. The method for emergency production of φ50 steel bars according to claim 7 is characterized in that: The first round hole hole type has a hole slot width of 90mm, a slot corner radius of 8mm, a groove bottom radius of 41mm, a roll gap of 12mm, a side wall inclination angle of 35°, and a hole height of 81mm. The first elliptical hole type has a hole height of 48mm, a slot width of 111mm, a slot corner radius of 5mm, a groove bottom radius of 90mm, and a roll gap of 10mm. The second round hole hole type, the third round hole hole type, and the fourth round hole hole type are of the same size, all with a hole slot width of 66mm and a slot bottom radius of 90mm. The fillet radius is 6mm, the groove bottom radius is 31mm, the roll gap is 10mm, the side wall inclination angle is 33°, and the hole height is 61mm. The hole height of the second elliptical hole is 40mm, the slot width is 85mm, the slot fillet radius is 5mm, the groove bottom radius is 65mm, and the roll gap is 8mm. The hole slot width of the fifth circular hole is 54mm, the slot fillet radius is 5mm, the groove bottom radius is 25mm, the roll gap is 8mm, the side wall inclination angle is 35°, and the hole height is 49mm.

9. The method for emergency production of φ50 steel bars according to claim 1, characterized in that: The calculation formula of the delay time t in S4 is shown in formula (3): Where L3 is the distance between the finished product rack and the pinch roller, V is the speed of the finished product rack, t 设 The preset delay time is 0.3s.

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