CN116254535A - Continuous pickling control method for high-strength steel of middle plate - Google Patents

Abstract

The invention discloses a continuous pickling control method for high-strength medium-plate steel, which belongs to the field of pickling steel production. The high-strength medium-plate steel has a thickness specification of 4.0-6.0mm and a yield strength of 500-650MPa; the specific process and control method are as follows: : (1) Feeding operation: The feeding operation unit includes the uncoiler inlet shear welding machine and the inlet looper; the welding machine adopts filler wire welding; the inlet looper is controlled by ≤50% of the set amount; (2) Phosphorus breaking operation: The elongation rate of phosphorus breaking machine is 0.2‑0.3%; (3) pickling operation: pickling speed 30‑50m/min; (4) tension leveling operation: tension leveling elongation rate is 0.2%; (5) coiling operation: including sheet building Straightening → cutting → coiling to get the finished product. Realize continuous pickling and batch stable production of high-strength steel with a thickness of 4.0-6.0mm and a yield strength of 500-650MPa.

Description

A method for controlling continuous pickling of high-strength medium-plate steel

technical field

The invention relates to a steel production method, in particular to a method for pickling high-strength steel with a thickness of 4.0-6.0mm, a yield strength of 500-650MPa and a width of ≤1300mm based on a continuous pickling production line.

Background technique

Due to the demand for cost reduction of steel used in industries such as automobiles, home appliances, and construction, the "hot instead of cold" pickling products of major steel mills have gradually replaced traditional steel.

As for high-strength automotive steel QSTE500TM~QSTE550TM series and S500MC-SM550MC series, thickness ≥ 4.0mm, the competitiveness of sales and profitability in the market is huge. At present, this type of steel with a thickness of 4.0-6.0mm cannot be rolled and produced by traditional cold rolling mills, and most of them are hot-rolled plates produced by pickling. For high-strength medium-plate steel with a thickness ≥ 4.0mm and yield strength ≥ 500MPA, due to the thickness and high strength of the strip steel, there is basically no production in domestic continuous pickling production lines. This type of high-strength medium-plate steel adopts a push-pull pickling production line For production, the push-pull pickling production line also has a phosphorus breaker and a pickling tank. The two strips do not need to be welded. The traction roller and the driving roller system are used for strip threading and coiling. Since the traction roller is used to push the strip threading and coiling, the production The speed is slow and the shape of the strip is poor. The push-pull pickling line is more suitable for the production of medium plate pickling products.

Based on this, various iron and steel enterprises are actively seeking the existing continuous pickling production line for production breakthrough, but the existing continuous pickling production line, the design and production of continuous pickling hot-rolled low carbon steel specifications thickness 0.8-6.0mm, width 900mm -1500mm, strength level: yield strength ≤ 500MPa, tensile strength ≤ 600MPa. The production line design technical appendix requires that pickling products with a thickness of 4.0-6.0mm must be low-carbon steel with a yield strength of less than or equal to 400MPa and a width of less than or equal to 1300mm. For example, the technology of "A Process and Equipment for Producing Thick Specifications Hot Substrate Patterned Galvanized Products" CN110359001A) can be used to realize the continuous pickling production of 0.8-4.0mm and yield strength of 290-320MPa, but the thickness is 4.0mm -6.0mm, yield strength exceeding 400MPa, there are the following technical defects: ①Because the high-strength steel adopts low-carbon feeding material, the content of alloy components such as Mn and Si is high, the strength is high, and the thickness of the strip steel is thick, the weld seam in the welding process of the welding machine Welding impermeability and pore defects are prone to occur; ②The high-strength steel strip of the medium plate is wound by a tension roller system. During the straightening and bending process of the phosphorus breaker and the tension leveler, greater tension is required. After repeated bending, it is easy to disconnect under the action of huge tension and cause a broken belt accident; ③The high-strength steel of the medium plate has high strength and the thickness of the strip steel is thick. The tension roller in front of the phosphorus machine is overloaded and the alarm stops; ④ Due to the thickness of the strip and the short length of the coil, the strip is prone to pickling defects during the pickling process, and at the same time, macular defects are prone to appear in the rinsing tank; ⑤After the flying shears are cut at the exit of the production line, the head is upturned, often jamming the upper cutting edge of the flying shears and causing parking, and the impact on the cutting blades is likely to cause damage to the cutting edges; And the opening of the head is large, so it cannot be packaged.

Therefore, how to overcome the design capability level of the production line and realize the continuous pickling and mass production of high-strength steel with a thickness of 4.0-6.0mm and a yield strength of 500-650MPa is an urgent technical problem in this field.

Contents of the invention

The technical task of the present invention is to provide a control method for continuous pickling of medium-plate high-strength automobile steel to realize continuous pickling and stable batch production with a thickness of 4.0-6.0mm and a yield strength of 500-650MPa.

The technical solution of the present invention to solve the technical problem is: a continuous pickling control method for high-strength medium-plate steel, which is characterized in that: the high-strength medium-plate steel has a thickness specification of 4.0-6.0mm and a yield strength of 500-650MPa; → Welding → Phosphorus breaking → Pickling and rinsing → Straightening → Shearing → Coiling → Finished product; the specific process and control methods are:

(1) Feeding operation: The feeding operation unit includes uncoiler, inlet shear, welding machine and inlet looper; the welding of welding machine adopts filler wire welding; the inlet looper is controlled by ≤50% set quantity;

(2) Phosphorus breaking operation: the elongation rate of the phosphorus breaking machine is 0.2-0.3%;

(3), pickling operation: pickling speed 30-50m/min;

(4) Pulling and leveling operation: the elongation rate of pulling and leveling is 0.2%;

(5) Coiling operation: including cutting → coiling to obtain finished products.

Further, the above-mentioned tension leveling and shearing also include building tension leveling.

Further, the selected filler wire is a low-C and low-Mn welding wire.

Further, the above welding wire composition includes C: 0.06-0.09%, Si: 0.6-0.95%, Mn: 1.50-2.1%, S: 0.10-0.16%, and P: 0.11-0.16%.

Further, the amount of export loopers is controlled by 12-20% of the amount of loopers.

Further, in the above pickling operation, the temperature of 1# tank is 75-78°C, the temperature of 2#, 3#, 4#, and 5# tanks is 73-75°C; the water temperature of the rinsing tank is 45-50°C.

Further, when the above-mentioned weld passes through the phosphorus breaker and the tension leveler, the phosphorus breaker and the tension leveler adopt the open mode.

Further, in the above coiling operation, the coil weight requirements: raw material coil weight 8t ≤ raw material coil weight ≤ 16t, finished product export is not divided into coils; raw material coil weight ≥ 21t, finished product coil weight control ≥ 10.5t; raw material coil weight ≥ 26t , The weight of the finished coil is controlled to be ≥12.5t.

Further, in the positioning procedure of the tape tail in the above coiling operation, the length of the tape tail is 5 cm.

Further, after the above-mentioned coiling operation, the position of the tape head is pressed on the saddle of the transport trolley after the coil is unloaded, and the opening degree of the tape head is reduced by the self-weight of the strip steel.

Compared with the prior art, the present invention has the following outstanding beneficial effects:

1. The present invention overcomes the design capability level of the production line and realizes the continuous pickling operation of high-strength steel with a thickness of 4.0-6.0mm and a yield strength of 500-650MPa;

2. Guarantee the quality of the weld seam at the high-strength steel welding part of the medium plate, ensure that the weld seam does not break during the production process, and realize the stability of production;

3. Improve the technical defects in the existing medium plate pickling technology that due to the slow production speed, it is easy to blacken the surface after pickling, and the surface of the strip steel in the rinsing section is easy to be oxidized and appear yellow spots;

4. Overcome the problem of the strip head warping after being cut by flying shears, avoid the situation that the cutting head is jammed and stop the steel, and reduce the parking spot defects in the pickling section and rinsing section;

5. Redistribute the straightening extension. Before the exit section is cut and sheared, through the re-straightening of the strip head and strip tail, reduce the elongation rate in the phase of phosphorus breaking and tension leveling, and avoid failure due to equipment load exceeding the limit. There is an early warning stop signal;

6. To overcome the problem that the strip cannot be packaged due to the loose outer ring and too large opening during the coiling process, and meet the packaging needs of subsequent products.

Description of drawings

Figure 1 is a schematic diagram of the macro arrangement of the present invention.

Fig. 2 is a structural schematic diagram of the tension straightening roller group of the present invention.

Fig. 3 is a structural schematic diagram of the steering roller set of the present invention.

Fig. 4 is a schematic structural view of the pinch roller set of the present invention.

Fig. 5 is a structural schematic diagram of the pressing wheel mechanism of the present invention.

Detailed ways

The present invention will be further described below in combination with specific embodiments.

For the purposes of the following detailed description, it is to be understood that the invention may assume various alternative modifications and step sequences unless expressly indicated to the contrary. Furthermore, except in any operative example or where otherwise indicated, all numbers expressing amounts of ingredients such as used in the specification and claims are to be understood in all instances as modified by the term "about". At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

It should also be understood that any numerical range recited herein is intended to include all subranges subsumed therein. For example, a range of "1 to 10" is intended to include all subranges between (and including) a stated minimum value of 1 and a stated maximum value of 10, that is, have a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

In this application, the use of the singular includes the plural and the plural encompasses the singular unless specifically stated otherwise. Also, in this application, the use of "or" means "and/or" unless explicitly stated otherwise, even though "and/or" may be explicitly used in some cases. Further, in this application, the use of "a" or "an" means "at least one" unless specifically stated otherwise. For example, "a" first material, "a" coating composition, etc. refers to one or more of any of these items.

The invention adopts hot substrate pickling process: hot-rolled raw material→uncoiling→welding→phosphorus breaking→pickling and rinsing→stretching and straightening→building and straightening→shearing→coiling→finished product. Product thickness specification 4.0-6.0mm.

The specific process and control method are:

1. Feeding operation

The feeding operation unit includes uncoiler, inlet shear, welding machine and inlet looper.

in:

(1), Welding machine welding process control

The high-strength steel in the present invention adopts low-carbon low-alloy high-strength steel, and the hot-rolled raw material alloy components Mn and Si content are high (C: 0.04-0.09%; Si: 0.15-0.45%, Mn: 1.25-1.55%), and the yield strength is ≥ 500MPa, the welding operation of the existing technology, the weld is prone to weld impermeability and porosity defects, and the qualified rate of weld quality is less than 40%. Therefore, push-pull pickling production lines are mostly used for production, and continuous pickling is difficult.

The present invention has carried out following control:

①Filler selection

The present invention uses filler wire for welding, and the filler wire used has a diameter of 0.8mm: in this embodiment, it is a low-C and low-Mn welding wire (C: 0.06-0.09%; Si: 0.6-0.95%, Mn: 1.50-2.1%, S: 0.10-0.16%, P: 0.11-0.16%).

Welding by gas shielded welding refines the grain size of the weld, effectively improves the plasticity and toughness, and then improves the bending performance of the welded joint, effectively solving the problem of weld cracking.

② Welding process parameters

Welding parameters of high-strength automobile steel with thickness ≥4.0mm: welding machine laser power 11.76-12Kw, welding speed 4.2-6.0m/min, rolling wheel pressure 75-98bar, preheating power 18-22Kw, annealing power 22-28Kw, clearance ( Transmission side/operating side) 0.10/0.12mm; Defocus -2.5mm.

The thickness difference between adjacent welded steel strips is at most 1mm, and the yield strength difference is ≤150MPa.

For example, the production specification is 4.0-6.0mm, the yield strength is less than 500MMPa, and no filler wire is used for welding.

For example, the production specification is 4.0-6.0mm, the yield strength is ≥500MMPa, the strength is high, the alloy components Si and Mn are high, and the wire filling is used for welding, and the wire feeding speed is 4.1-6.2m/min.

The specific welding parameters are as follows

(2) Loop volume control

The main function of the entrance looper is to store the strip steel, so as to ensure a short adjustment time in case of a short-term failure of the production line.

The production line is about 2,000 meters from the welding machine, the entrance looper, the pickling section, the rinsing section, the tension leveler, the export looper, to the output slitter and coiler of the production line. There are 6 layers of strip steel in the entrance looper, with a total length of 1050 meters; in the looper, the amount of looper is controlled by the hoisting equipment pulling the trolley forward and backward. During the steel filling process, the movement of the looper trolley intensifies, and the pulling force suddenly increases. At the same time, the high-strength steel welding of the medium plate may cause weld rewelding.

After the strip comes out of the tension leveler, it enters the export loop, the exit loop is 540 meters, and there are four strips in total. The looper is too large, and the hoist pull trolley needs more pulling force to move. In order to protect the hoisting equipment and ensure the stability of the high-strength steel weld, the amount of high-strength inlet looper and outlet looper of the medium plate is limited.

For example, the production specification is 4.0-6.0mm, the yield strength is less than 500MMPa, the inlet looper is ≤70%, and the outlet looper is ≤40%;

For example, the production specification is 4.0-6.0mm, the yield strength is ≥500MMPa, the inlet looper is controlled by ≤50% of the set amount, and the middle plate high carbon steel welds in the inlet looper are ≤2; the export looper amount is controlled by 12-20% Quantity control.

The above control guarantees the quality of the weld seam at the welding place of the high-strength steel of the medium plate, ensures that the weld seam does not break during the production process, and realizes the stability of production.

2. Phosphorus breaking operation:

The high-strength steel of the medium plate has high strength and the thickness of the strip steel is thick. During the process of straightening the plate shape and the oxidized iron scale on the damaged strip steel surface, the tension roller in front of the phosphorus breaker is overloaded and the alarm stops.

Weld seam protection: The weld seam passes through the phosphorus breaker and adopts the open mode.

For example, the production specification is 4.0-6.0mm, the yield strength is less than 500MMPa, and the elongation of the phosphorus breaker is 0.6-0.8%;

For example, the production specification is 4.0-6.0mm, ≥500MPa, the high-strength steel of the medium plate controls the elongation of the phosphorus breaker to 0.2-0.3%, which can achieve the post-pickling effect of the damaged scale and improve the shape of the strip to a certain extent.

3. Pickling operation:

Due to the thickness of the strip steel and the short length of the steel coil, the strip steel is prone to over-pickling defects during the pickling process, and at the same time, it is prone to macular defects in the rinsing tank.

(1) Pickling speed

From the welding machine at the entrance of the production line to the coiling machine at the exit of the production line, the total length of the entire pickling production line is about 2,000 meters. According to the 18-28 tons of high-strength steel for each medium plate, the total length of each strip is about 350-600 meters. There are about 3-5 coils in the production line, and there are 3-5 medium-plate high-strength steel welds in the entire production line. At the same time, during the entry welding process of the high-strength medium-plate steel, repeated welding of the welds will affect the production time. In order to avoid the risk of shutting down the high-strength medium-plate steel and disconnecting the welds of the high-strength medium-plate, the overall production speed is reduced.

For example, the production specification is 4.0-6.0mm, the yield strength is less than 500MPa, the quality of the weld seam welded by the welding machine is good, the welding time is short, the stability of the weld seam is high, and the strip pickling process speed is 40-100m/min.

For example, the production specification is 4.0-6.0mm, ≥500MPa, in order to ensure the stability of the production process, the pickling speed is 30-50m/min.

(2) Pickling parameters

For example, the production specification is 4.0-6.0mm, ≥500MPa, low temperature and low concentration control is adopted, the temperature of tank 1# is 75-78°C, and the temperature of tank 2#, 3#, 4#, and 5# is 73-75°C; due to the strip production speed Slow, the temperature is too high, and the surface of the strip steel is prone to over-pickling. At the same time, the high-strength steel of the medium plate contains high Si and Mn alloy components, and the surface of the strip steel is also prone to blackening after pickling. Therefore, the high-strength steel of the medium plate is controlled at low temperature and low concentration. , the concentration of free acid in 1# tank is 45-50g/l; due to the slow production speed of medium plate high-strength steel, the protective water film on the surface of the strip steel in the rinsing tank is easily evaporated, causing the surface of the strip steel to be oxidized to form macular defects, so the rinsing water temperature Low temperature control reduces the evaporation rate of the water film on the surface of the strip, the water temperature of the rinsing tank is 45-50 ℃, and the rinsing tank is controlled by a passivator of 1.0-1.5‰. In the production of high-strength medium plate steel, the operator automatically increases the concentration of the passivating agent added in the rinsing section one hour in advance. The effect of the passivating agent in the rinsing water makes the surface of the strip steel cleaner, and a protective film is formed on the metal surface to prevent the surface of the strip steel from Oxidized.

For example, the production specification is 4.0-6.0mm, the yield strength is less than 500MPa, the passivation agent is 0.8‰, and the rinse water temperature is 45-60°C.

It improves the technical defects in the existing medium plate pickling technology that due to the slow production speed, the pickling surface is easily blackened, and the surface of the strip steel in the rinsing section is easily oxidized and yellow spots appear.

4. Pulling and straightening operation

Weld seam protection: Weld seam over tension leveler with open mode.

For example, the production specification is 4.0-6.0mm, the yield strength is less than 500MPa, and the tensile elongation is 0.4%;

For example, if the production specification is 4.0-6.0mm and the yield strength is ≥500MPa, the elongation rate of tension leveling is 0.2%. If the elongation rate of tension leveling is too large, the tension will be too large, and the alarm and shutdown signal will easily appear.

Normal production of low-carbon steel uses 1 roll box, 1 bending roll and 1 straightening roll; in the production of medium-plate high-strength automotive steel, double-roll boxes are used at the same time, and 1 bending roll and 2 straightening rolls are used to ensure the shape of the plate The rollers are put into use at the same time.

5. Coiling operation

Including building straightening → cutting → coiling to get the finished product.

The described straightening of the sheet can be realized by using the tension roller and the straightening roller before the shearing equipment in the coiling operation. For the re-straightening of the strip head and strip tail, reduce the elongation rate in the stages of phosphorus breaking and tension leveling, and avoid the early warning signal of broken belt stop due to equipment load exceeding the limit.

Roll Weight Requirements:

1) The weight of the raw material coil is 8t≤the weight of the raw material coil≤16t, and the finished product is not divided into coils for export;

2) Raw material coil weight control ≥ 21t (1250mm), finished product coil weight control ≥ 10.5t (width 1250mm);

3) Raw material coil weight ≥ 26t (1500mm), finished coil weight control ≥ 12.5t (width 1500mm),

The finished product export can be divided into 2 sub-volumes at most. The weight of the raw material is too small and the length of the strip steel is too short. If the strip steel has repeated welding or other short-term equipment problems during the welding process of the welding machine, there is no adjustment time, which will easily cause shutdown and parking spot defects. At the same time, the high-strength steel weld seam The quantity increases in the production line, and the risk of weld breakage increases.

Strap requirements:

≥4.0mm pickling plate with three straps. If the strip is too thick, the strip tail of the outer ring of the strip has a slight opening after coiling. The opening means that the strip tail of the outermost ring cannot fit the steel coil tightly, and the strip tail is the second circle away from the strip. distance.

The opening degree has the risk of the straps collapsing. Adding three straps can tighten the steel coil, and the second is from the safety point of view of preventing the straps from collapsing.

Under the hardware conditions of the existing pickling production line, after the above process improvement, it can stably produce medium plate products with a thickness specification of 4.0-6.0mm, yield strength ≥ 500MPa, and width ≤ 1300mm. In 2022, 2,100 tons of 4.0-6.0mm QSTE500TM~QSTE550TM series and S500MC-SM550MC series thick plate high-strength steel will be produced, with a pass rate of 98.6% in the first quality inspection, and no welding seam breakage accident occurred.

In actual production, high-strength steel for medium plates is prone to defects such as loose rings on the outer ring, large opening of the head, and upturning of the head at the export, which affects subsequent packaging processing: due to the thickness and high strength of the strip steel, flying shears at the export of the production line After cutting, the belt head is upturned, often jamming the guide plate and causing parking; and in the prior art, rubber sleeves and belts are often used to coil the medium plate automobile steel, and the tension of the belt is small, and the outer and inner rings of the steel plate are easy to appear. In the case of the loose ring, the loose ring of the high-strength steel outer ring of the medium plate cannot be packaged at all and can only be degraded in quality. In addition, due to the high strength of the high-strength steel of the medium plate and the thickness of the strip steel, it is not easy to coil, and the tail opening of the strip steel is too large after the tail of the strip coil is rolled.

In order to better realize the coiling operation, reduce the opening of the tape head and prevent steel jamming, and at the same time establish and straighten the second time, the invention improves the export equipment of the pickling production line.

The present invention provides an export equipment of a pickling production line. The macro arrangement of the equipment is shown in FIG. In this embodiment, a pinch roll set 3 is also included between the tension straightening roll set 1 and the slitting assembly 4 , and an oiler 2 is also included between the tension straightening roll set 1 and the pinch roll set 3 . There are two groups of described steering roller group 6 and reel 7.

The tension straightening roller group 1 is used to establish tension to ensure the operation of the strip steel; the oiler 2 is used to oil the surface of the strip steel to prevent corrosion; the pinch roller group 3 is used to ensure that the strip steel is cut The strip steel in the process is stable to prevent the strip steel from slipping; the slitting assembly 4 cuts the continuous strip steel in coils; The steel strip enters the reel for coiling; the reel 7 rolls the steel strip 5 into coils.

Described tension straightening roller group 1 is used for forming tension between coiling unit spool 7, as shown in Figure 2, described tension straightening roller group 1 comprises the No. 1 pressure roller 16 that is installed on the roll stand, No. I tension roller 15, No. II pressure roller 12, No. II tension roller 14, straightening roller 13 and hydraulic cylinder 17.

The No. I pressure roller 16 is above the No. I tension roller 15, and is pressed to the No. I tension roller 15 under the action of the pressing device. Under the action of the device, it is pressed to No. II tension roller 14. In this embodiment, the roll diameters of the No. I tension roller 15 and the No. II tension roller 14 are φ1250, and the roll diameters of the No. I pressing roller 16 and the No. II pressing roller 12 are φ270. The specific structure and control method of the pressure roller and the pressing device are prior art, and will not be repeated here.

The No. I pressure roller 16 is located in front of the No. II tension roller 14 . The running relationship of the strip steel 5 in the tension straightening roller group 1 is a reverse S shape, specifically passing between the No. I pressure roller 16 and the No. I tension roller 15, around the No. I tension roller 15, and the No. II tension roller 14, from Between No. II pressure roller 12 and No. II tension roller 14, enter above the straightening roller 13.

During normal production, No. I press roller 16 and No. II press roller 12 are lifted. Before the slitting assembly 4 is to be slit, the outlet strip 5 runs at 40 min/m. No. I press roller 16 and No. II press roller 12 After receiving the pressing signal, the pressing device will press down to the position in about 2 seconds; the purpose of the pressing operation of the two pressure rollers is to prevent the strip steel from being fixed after the flying shear cuts the strip steel 5, and prevent the strip steel from slipping backwards. steel case.

The straightening roller 13 is located at the front and bottom of No. II tension roller 14 . The hydraulic cylinder 17 is used to realize the rise of the straightening roller 13. The hydraulic cylinder 17 can be directly connected to both ends of the straightening roller 13, or it can be realized by the leverage of the connecting frame 11 as in this embodiment. The middle section of the connecting frame 11 is hinged with the roller frame, the front end is used to jack up the straightening roller 13, and the rear end is connected with the telescoping rod lower end of the hydraulic cylinder 17.

The depressing device of the No. I press roller 16, the depressing device of the No. II press roller 12 and the described hydraulic cylinder 17 are interlocked controlled by an electric program. That is to say, when the production thickness is greater than or equal to 4.0mm, the operator selects the state of chain operation. At this time, when the No. I press roller 16 and the No. II press roller 12 are pressed down, the hydraulic cylinder 17 drives the straightening roller 13 to lift up 15mm , with No. II pressure roller 12 synchronous action, at this time straightening roller 13 and II No. direct action.

As shown in FIG. 3 , the turning roller set 6 includes a turning roller 64 installed on the turning roller frame, a rear pressing roller 62 , a front pressing roller 66 , a rear pressing assembly and a front pressing assembly. Between the turning roller 64 and the reel 7 is a guide plate platform 68 .

The said rear pressing roller 62 is above the steering roller 64, and the depressing contact between the rear pressing roller 62 and the steering roller 64 is realized by the rear pressing assembly. In this embodiment, the rear pressing assembly includes a rear hydraulic rod 63 and a rear pressure beam 61, the lower end of the rear hydraulic rod 63 and the front end of the rear pressure beam 61 are respectively hinged to the steering roller frame, and the rear hydraulic pressure The upper end of the rod 63 is hinged with the rear end of the rear pressure beam 61 . The rear pressure beam 61 is used to press the rear pressure roller 62 to the steering roller 64 .

The front pressing roller 66 is above the front of the steering roller 64, and the pressing contact of the front pressing roller 66 and the steering roller 64 is realized by the front pressing down assembly. In this embodiment, the front pressing assembly includes a front hydraulic rod 67 and a front pressure beam 65, the lower end of the front hydraulic rod 67 and the rear end of the front pressure beam 65 are respectively hinged with the steering roller frame, and the front The upper end of the hydraulic rod 67 is hinged with the front end of the front pressure beam 65 . The front pressing beam 65 is used to press the front pressing roller 66 to the steering roller 64 .

When the slitting assembly 4 cuts and divides into rolls, the tail of the previous roll is flicked under the action of no tension. The front pressure roller 66 is that the strip steel 5 is put into use when threading the band, and the effect is that the tape head is drawn to the reel 7 by the threading guide plate platform 68 and coiled, and the tail is not thrown into use. When the production thickness is greater than or equal to 4.0mm, the operator chooses to use the front pressure roller 66, and starts the rear pressure roller 62 and the front pressure roller 66 to press down at the same time when the coiler strip is flicking. The steel has a tendency to buckle down so that the tail strip fits the coil after it has been coiled. And optimize the pressure of the pressure roller 62 after steering, and adjust it from 90MPa to 110MPa. When the thickness of the steel strip is less than 4.0mm, the front pressure roller 66 will not be put into use.

As shown in Fig. 4, described pinch roller group 3 comprises idler roller 34, upper pinch roller 32, lower pinch roller 33 and pressing down device 31, and its effect makes strip steel in slitting assembly 4 shearing process The middle strip steel remains stable, and it can also prevent the strip steel from slipping backward under the action of losing tension.

The idler roller 34 is positioned at the rear of the lower pinch roller 33, and the roller surface of the idler roller 34 is higher than the lower pinch roller 33 roller surface, so that the strip steel 5 enters the upper pinch roller 32 and the lower pinch roller 33 obliquely. between. The pressing device 31 is used to drive the upper pinch roller 32 to press the lower pinch roller 33 . In this embodiment, the roller surface of the idler roller 34 is 10 mm higher than the roller surface of the lower pinch roller 33 .

When the strip steel decelerates at 40m/min, before the strip steel 5 is sheared by the slitting assembly 4, the upper pinch roll 32 is simultaneously with the No. I press roll 16 and No. II press roll 12 of the tension straightening roll group 1 Pressing down, a simple bending action is formed between the supporting roller 34 and the upper pinch roller 32 and the lower pinch roller 33, so that the strip head of the strip steel after the slitter assembly 4 shears is in a downward buckling trend.

The slitting assembly 4 includes an upper cutting edge 42, a lower cutting edge 43, and a pressing wheel mechanism.

As shown in FIG. 5 , the pressure wheel mechanism includes a pressure wheel 41 , a connecting rod 45 , and a C-shaped frame 46 .

The C-shaped frame 46 is installed on the upper cutting edge 42 and is linked with it.

The upper arm and the lower arm of the C-shaped frame 46 have a through hole, the connecting rod 45 passes through the through hole, the upper end is fixedly connected with the frame of the cutting assembly 4, and the lower end is connected with the axle of the pressure roller 41 connect. The position above the upper arm of the C-shaped frame 46 where the connecting rod 45 is threadedly connected with a threaded button 44, and the position above the lower arm of the C-shaped frame 46 is fixedly provided with a clamping plate, and the clamping plate and the upper arm of the C-shaped frame 46 Compression springs 47 are sleeved therebetween. In this embodiment, the pressure wheel 41 is a 5-inch iron core rubber-lined polyurethane pressure wheel.

During the free state (state A), the bottom of the pressure roller 41 is about 50mm lower than the lowermost end of the upper cutting edge 42 . The C-shaped frame 46 moves downward along with the upper cutting edge 42 (state B), when the upper cutting edge 42 is at the lowest position, the pinch roller 41 is pressed on the strip steel plane, and due to the existence of the compression spring 47, the pinch roller 41 remains constant. pressure (<15bar), when the production thickness of the unit is ≥4.0mm and the highest strength is ≥500MPa, the bottom of the pressure roller 41 is about 30mm lower than the lower end of the upper cutting edge 42, which effectively solves the problem of strip warping and ensures that the leading edge is cut on the upper side. There are 42 blades, and the belt threading is successfully completed.

In order to reduce the opening of the tape head, in the optimization plan, the positioning procedure of the tape tail is revised, and the length of the tape tail is adjusted from 8cm to 5cm. of opening.

It should be noted that the parts not described in detail in this embodiment are technologies well known in the art.

It should be noted that the specific embodiments of the present invention have described the present invention in detail, and for those skilled in the art, various obvious changes to it without departing from the spirit and scope of the present invention are all possible. Within the protection scope of the present invention.

Claims (10)

1. A continuous pickling control method for high-strength medium-plate steel, characterized in that: the high-strength medium-plate steel has a thickness specification of 4.0-6.0mm and a yield strength of 500-650MPa; it includes decoiling → welding → phosphorus breaking → pickling and Rinsing → straightening → cutting → coiling → finished product; the specific process and control methods are: (1) Feeding operation: The feeding operation unit includes uncoiler, inlet shear, welding machine and inlet looper; the welding of welding machine adopts filler wire welding; the inlet looper is controlled by ≤50% set quantity; (2) Phosphorus breaking operation: the elongation rate of the phosphorus breaking machine is 0.2-0.3%; (3), pickling operation: pickling speed 30-50m/min; (4) Pulling and leveling operation: the elongation rate of pulling and leveling is 0.2%; (5) Coiling operation: including cutting → coiling to obtain finished products. 2. The method for controlling continuous pickling of medium plate high-strength steel according to claim 1, characterized in that: said stretching and shearing also include building and straightening. 3. The method for controlling continuous pickling of medium-plate high-strength steel according to claim 1, characterized in that: the selected filler wire is a low-C and low-Mn welding wire. 4. The method for controlling continuous pickling of medium plate high strength steel according to claim 3, characterized in that: the welding wire components include C: 0.06-0.09%, Si: 0.6-0.95%, Mn: 1.50-2.1%, S : 0.10-0.16%, P: 0.11-0.16%. 5. The method for controlling continuous pickling of high-strength medium plate steel according to claim 1, characterized in that: the amount of loops at the outlet is controlled by 12-20% of the amount of loops. 6. The continuous pickling control method for high-strength medium plate steel according to claim 1, characterized in that: in the pickling operation, the temperature of tank 1# is 75-78°C, and the temperature of tank 2#, 3#, 4#, and 5# The tank adopts 73-75°C; the water temperature of the rinsing tank is 45-50°C. 7. The continuous pickling control method for medium-plate high-strength steel according to claim 1, characterized in that: when the weld passes through the phosphorus breaker and the tension leveler, the phosphorus breaker and the tension leveler adopt an open mode. 8. The continuous pickling control method for medium plate high-strength steel according to claim 1, characterized in that: in the coiling operation, the coil weight requirement is: raw material coil weight 8t ≤ raw material coil weight ≤ 16t, and finished product exports are not divided Roll; raw material coil weight ≥ 21t, finished product coil weight control ≥ 10.5t; raw material coil weight ≥ 26t, finished product coil weight control ≥ 12.5t. 9. The method for controlling continuous pickling of high-strength steel for medium plates according to claim 1, characterized in that: in the positioning procedure of the tape tail in the coiling operation, the length of the tape tail is 5 cm. 10. The method for controlling continuous pickling of high-strength medium-plate steel according to claim 1, characterized in that: after the coiling operation, the position of the tape head is pressed onto the saddle of the transport trolley after the coil is unloaded, and the self-weight of the strip steel is reduced. Small lead opening.

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