CN107262538B - A kind of derusting descaling process of steel band - Google Patents

Abstract

The invention relates to a process for removing rust and scale of a steel strip, which comprises the following steps of uncoiling, peeling, flattening, shot blasting, washing and winding; the peeling includes peeling the upper surface process and peeling In the lower surface process, the flattening adopts a multi-roller flattening machine, and the multi-roller flattening machine passes the steel strip through the gap between the upper and lower rollers to correct the deformation of the plate, and uses a high-pressure jet nozzle for shot peening. The angle between the spray nozzle and the steel strip is 35-70 degrees. The washing includes initial washing and fine washing. The nozzles during washing are fan-shaped nozzles. The process of the invention has small water consumption, reliable and stable system operation, and good rust and scale removal effects.

Description

A kind of derusting and descaling process of steel strip

technical field

The invention relates to a surface treatment process of a steel strip, more specifically, it relates to a process of derusting and descaling a steel strip.

Background technique

Hot-rolled steel strip needs derusting and descaling before cold rolling. At present, several optional processes are: air-flow sand blasting, drum sand blasting and high-pressure water shot blasting. These methods have large water consumption, unstable system operation, and cannot effectively carry out the surface of the steel strip. Therefore, it is necessary to develop a process with small water consumption, reliable and stable system operation, and good effect of rust and scale removal.

Contents of the invention

The purpose of the present invention is to provide a steel strip derusting and descaling process with small water consumption, reliable and stable system operation, and good derusting and descaling effects.

In order to achieve the above object, the present invention includes the steps of unwinding, peeling, flattening, shot blasting, washing and winding in sequence.

Further, the shelling includes the process of peeling the upper surface and the process of peeling the lower surface.

Further, the peeling adopts a pair of wheel type sheller for shelling, and the pair of wheel type sheller includes a bending wheel, an auxiliary wheel arranged opposite to the bending wheel, and a pair of righting wheels, so The bending wheel is connected with the motor, and the righting wheel is located on both sides of the bending wheel and the auxiliary wheel; more than one pair of wheel-type shelling machines are set, and the steel strips pass through the pair of wheel-type shelling machines in turn, adjacent to each other. The opposite bending of the steel plate inside the wheel sheller. Preferably, a peeling process is arranged between or after the shelling upper surface process and the shelling lower surface process.

Further, the extruding step is to pass the steel strip through the gap between the two extruding rollers arranged up and down, and connect the lower extruding roller to the motor to compress the steel plate by 0.01-0.1mm, so that the rust layer is compressed and deformed, Finish the peeling.

Further, the flattening adopts a multi-roller flattener, and the multi-roller flattener passes the steel strip through the gap between the upper and lower rollers to correct the deformation of the plate;

Adopt high-pressure injection nozzle during shot blasting, the included angle of described high-pressure injection nozzle and steel strip is 35-70 degree, and injection pressure is 25.0-50.0MPa, and described high-pressure injection nozzle and shot box and power are 150-300kw respectively The high-pressure water pump is connected, and the high-pressure water pump is connected with the pool through a large water pump with a power of 15-30kw.

Further, the washing includes initial washing and fine washing, both of which are supplied with water by a small water pump with a power of 10-20kw, and the small water pump with a power of 10-20kw is connected to the pool; the nozzles during washing are fan-shaped nozzle.

Further, between washing and winding, there is also a sanding step.

Furthermore, this process is also equipped with a material edge reflection device, which is composed of a reflection plate set on the bracket, and bounces back the sand shot flying out of the steel plate during shot peening, so that it impacts the edge area of the steel plate surface, effectively strengthening the edge. area rust removal.

Furthermore, this process is also equipped with an automatic detection device that automatically adjusts the feeding speed, injection pressure and sand supply amount.

The positive effect of the present invention is as follows:

The present invention (1) adopts the pretreatment peeling process and equipment, which improves the production speed and reduces the pressure during subsequent shot peening.

(2) During shot peening, the high-pressure injection nozzle is a fan-shaped nozzle, so that the mixture of sand shot and water is sprayed out through the high-pressure injection nozzle in a layered spray, saving water and improving the energy efficiency of the equipment and production labor efficiency.

(3) The included angle between the high-pressure jet nozzle and the steel strip is improved, and the angle between the high-pressure jet nozzle and the steel strip is 35-70 degrees, which improves the effect of derusting and descaling, and improves the treatment effect.

(4) The setting of the extruding process further improves the quality of the product; the setting of the flattening process further improves the quality of the product.

(5) Fan-shaped nozzles are used for the initial washing and fine washing, which can effectively remove the residual pellets, rust powder, and other adsorbed metal powder on the surface of the steel strip, and provide a clean surface for the subsequent process.

(6) There is also a sanding step between washing and winding. The continuous abrasive belt and the steel belt are in close contact, and the steel belt is continuously polished to further improve the effect of rust and scale removal and meet the requirements of galvanized finish.

(7) During the shot peening process, a material edge reflection device is also set up, which can bounce back the sand shot flying out of the steel plate during shot peening, so that it can impact the edge area of the steel strip surface, effectively strengthening the rust removal effect on the edge area.

(8) The process of the present invention only uses three water pumps, which reduces the number of water pumps and a large number of pipelines and pipe fittings, thereby reducing the workload and costs of equipment installation, operation, maintenance and replacement, and avoiding equipment damage. probability, improving the reliability of the system operation.

Description of drawings

Fig. 1 is the technological process schematic diagram of the present invention;

In the accompanying drawings, 1 uncoiler, 2 straightening wheels, 3 bending wheels, 4. auxiliary wheels, 5 squeeze rollers, 7 high-pressure water pumps, 9 small water pumps, 10 winders, 11 sanding machines, 14 high-pressure jet nozzles , 15 multi-roller flattening machine, 17 pool, 18 plunger pump.

Detailed ways

Embodiments of the present invention will be further described in detail below.

In the present invention, the steel strip is sequentially subjected to the following steps, which can effectively remove rust and scale after uncoiling, shelling, flattening, shot blasting, washing and winding.

First, the steel strip to be processed is uncoiled by the uncoiler 1, conveyed by the feed roller, and then peeled off.

The shelling includes a peeling upper surface process and a shelling lower surface process, and the shelling adopts a pair of wheel type sheller for shelling, and the pair of wheel type sheller includes a bending wheel 3, and the bending plate The auxiliary wheel 4 set opposite to the wheel 3, the righting wheel 2 arranged in pairs, the bending wheel 3 is connected with the motor, and the righting wheel 2 is located on both sides of the bending wheel 3 and the auxiliary wheel 4; There is more than one shelling machine, and the steel strips pass through the pair of wheel shellers in turn, and the steel plates in the adjacent pair of wheel shellers are reversely bent. When the steel strip goes through the upper surface process, the steel strip passes through the centering wheel 2, the bending wheel 3 and another centering wheel 2 in sequence. The rust layer is squeezed and peeled off, thus completing the peeling. The rust layer on the upper surface of the steel strip is extruded and peeled off through the upper surface process. After the upper surface process, the steel strip is reversely bent, and the rust layer on the lower surface is extruded and peeled off, thereby completing the peeling of the lower surface. Multiple wheel shellers can be set up to perform shelling repeatedly.

A peeling process can be arranged between the peeling upper surface process and the peeling lower surface process, or a peeling process can also be arranged after the peeling upper surface process and the peeling lower surface process. The extruding process is to pass the steel strip through the gap between the two extruding rollers 5 arranged up and down, the extruding roller 5 below is connected to the motor, and by adjusting the gap between the two extruding rollers 5, the steel plate is compressed by 0.01 ~0.1mm, make the rust layer compressed and deformed, complete the extrusion, stretch and compress, go out and loosen the remaining scales, and further remove the rust layer.

The flattening adopts a multi-roller flattening machine 15, and the multi-roller flattening machine 15 passes the steel strip through the gap between the upper and lower rollers, corrects the deformation of the steel strip, and makes half of it straight, which is beneficial to the rust removal process.

The steel strip after flattening carries out shot-peening, adopts high-pressure injection nozzle 14 during shot-peening, preferably, the cross-section of described high-pressure injection nozzle 14 is fan-shaped, and the sand shot in the sand shot box 6 is projected to the steel strip surface at high speed, clearly Rust and dirt. The included angle between the high-pressure injection nozzle 14 and the steel strip is 35-70 degrees, and the injection pressure is 25.0-50.0MPa. The high-pressure injection nozzle 14 and the shot box 6 are connected to the high-pressure water pump 7 respectively, and the high-pressure water pump 7 passes through Power is the motor drive of 150-300kw, and is connected with pond 17 by large water pump 16. When in use, the mixture of sand shot and water is ejected through the high-pressure injection nozzle 14, spraying in layers, saving water, improving the energy use efficiency of the equipment and production labor efficiency, the angle between the high-pressure injection nozzle 14 and the steel strip is 35-70 It is sprayed from the upper and lower surfaces of the steel strip, so that the mixture of sand shot and water can be improved to better treat the surface of the steel strip, improving the effect of rust and scale removal, and improving the treatment effect. Preferably, a material edge reflection device that can bounce back the sand shot flying out of the steel plate during shot peening is also provided. Surroundings, the sand shot flying out of the steel plate during shot peening can be bounced back to make it impact the edge area of the steel strip surface, effectively strengthening the rust removal effect on the edge area.

Wash the steel strip after shot blasting, and clean the surface of the steel strip after removing the rust layer and dirt. The washing includes initial washing and fine washing, and the initial washing and fine washing pass through a small Water pump 9 supplies water, and described power is that the small water pump 9 of 10-20kw and the large water pump 16 of 15-60kw are all connected with pool 17, and pool 17 is the large water pump 16 that power is 15-30kw and the large water pump 16 that power is 10-20kw The small water pump 9 supplies water, and then the water is divided into several roads, which are used for shot blasting and cleaning respectively. The power of the small water pump 9 is 10-20kw, and preparations are made when starting and stopping. The power of the large water pump 16 is 15-30kw. Turn on the supply of working water during operation.

This can ensure the operational reliability of the system. When washing, the nozzle adopts a fan-shaped nozzle to improve the cleaning effect. The nozzles for initial washing and fine washing are all fan-shaped nozzles, which can effectively remove residual pellets, rust powder, and other adsorbed metal powders on the surface of the steel strip, providing a clean surface for subsequent processes.

Preferably, between washing and winding, there is also a sanding step. The sanding is an abrasive belt sanding process, which is completed by a sander 11. The continuous abrasive belt and the steel belt are in close contact, and the steel belt is continuously With polishing, to further improve the effect of rust and scale removal, to meet the requirements of galvanized finish.

Finish by winding machine 10 when winding.

In order to improve the detection level of the whole process, in the present invention, an automatic detection device is also provided to automatically adjust the feeding speed through the frequency converter, the injection pressure through the frequency converter and the sand supply amount through the regulating valve. By installing a speed sensor on the conveyor belt that conveys the steel belt, the speed sensor is connected with a PCL controller, and the PCL controller is connected with a motor that controls the transmission of the conveyor belt, thereby realizing automatic adjustment of the feeding speed. A pressure sensor is provided in the high-pressure injection nozzle 14, and the pressure sensor is connected to a PCL controller, and the PCL controller is connected to a frequency converter of the motor, thereby realizing automatic adjustment of the injection pressure.

The process production line of the present invention is 400mm, and a plunger pump 18 of 100-200kw can be equipped between the high-pressure injection nozzle 14 and the high-pressure water pump 7, the water flow rate is within the range of 10-20 cubic meters per hour, and the pressure is within the range of 30-50MPa Adjustable, finally through the process of the present invention, a surface without rust and phosphorus is produced, and the surface roughness is not greater than 8 microns, the brightness is uniform, and the edge rust is well removed. The power consumption is 20-50% lower than the original technology, and the equipment investment is not higher than the original technology. The surface finish of the treated steel strip is less than 5 microns, and the diameter of the micro-concaves on the surface is about 0.04-0.07mm, evenly distributed, and the hardness is close to the original hardness. , which are better than the original technique.

To sum up, the present invention (1) adopts the pretreatment peeling process and equipment, which improves the production speed and reduces the pressure during subsequent shot peening.

(2) During shot blasting, the high-pressure injection nozzle 14 is a fan-shaped nozzle, so that the mixture of sand pellets and water is sprayed out through the high-pressure injection nozzle 14, spraying in layers, saving water and improving the energy efficiency of equipment and production labor efficiency

(3) The angle between the high-pressure jet nozzle 14 and the steel strip is improved, and the angle between the high-pressure jet nozzle 14 and the steel strip is 35-70 degrees, which improves the effect of derusting and descaling, and improves the treatment effect.

(4) The setting of the extruding process further improves the quality of the product; the setting of the flattening process further improves the quality of the product.

(5) Fan-shaped nozzles are used for the initial washing and fine washing, which can effectively remove the residual pellets, rust powder, and other adsorbed metal powder on the surface of the steel strip, and provide a clean surface for the subsequent process.

(6) There is also a sanding step between washing and winding. The continuous abrasive belt and the steel belt are in close contact, and the steel belt is continuously polished to further improve the effect of rust and scale removal and meet the requirements of galvanized finish.

(7) During the shot peening process, a material edge reflection device is also set up, which can bounce back the sand shot flying out of the steel plate during shot peening, so that it can impact the edge area of the steel strip surface, effectively strengthening the rust removal effect on the edge area.

(8) The process of the present invention only uses three water pumps, which reduces the number of water pumps and a large number of pipelines and pipe fittings, thereby reducing the workload and costs of equipment installation, operation, maintenance and replacement, and avoiding equipment damage. probability, improving the reliability of the system operation.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the patented invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (1)

1. a kind of derusting and descaling process of steel strip, is characterized in that: it comprises carrying out following steps successively, decoiling, shelling, flattening, shot blasting, washing and winding; The peeling includes a shelling upper surface process and a shelling lower surface process; The shelling adopts a pair of wheel type sheller for shelling, and the pair of wheel type sheller includes a bending wheel (3), an auxiliary wheel (4) arranged opposite to the bending wheel (3), a pair of The righting wheel (2) that is set, the described bending wheel (3) is connected with motor, and described righting wheel (2) is positioned at the both sides of described bending wheel (3) and auxiliary wheel (4); There is more than one shelling machine, the steel belt passes through the paired wheel sheller in turn, and the steel plates in the adjacent paired wheel sheller are reversely bent; A peeling process is arranged between or after the shelling upper surface process and the shelling lower surface process; The extruding process is to pass the steel strip through the gap between the two extruding rollers (5) arranged up and down, and the extruding roller (5) below is connected to the motor to compress the steel plate by 0.01~0.1mm, so that the rust layer is protected. Compression deformation, complete extrusion; The flattening adopts a multi-roller flattener (15), and the multi-roller flattener (15) passes the steel strip through the gap between the upper and lower rollers to correct the deformation of the plate; A high-pressure injection nozzle (14) is used for shot peening. The angle between the high-pressure injection nozzle (14) and the steel strip is 35-70 degrees, and the injection pressure is 25.0-50.0MPa. The high-pressure injection nozzle (14) and the sand shot The tanks (6) are respectively connected to high-pressure water pumps (7) with a power of 150-300kw, and the high-pressure water pumps (7) are connected to the pool (17) through a large water pump (16) with a power of 15-30kw; Washing includes initial washing and fine washing, both of which are supplied with water by a small water pump (9) with a power of 10-20kw, and the small water pump (9) with a power of 10-20kw is connected to the pool (17); The nozzles during washing are fan-shaped nozzles; Between washing and winding, there is also a sanding step; In this process, there is also a material edge reflection device that can bounce back the sand shot flying out of the steel plate during shot peening. The device is composed of a reflection plate arranged on the bracket; In this process, an automatic detection device is also set up to automatically adjust the feeding speed, injection pressure and sand supply amount.