阅读说明：本技术 一种拉矫机矫直低牌号无取向硅钢的方法 (Method for straightening low-grade non-oriented silicon steel by withdrawal straightening machine ) 是由 韩玉龙 吴明明 于 2021-01-04 设计创作，主要内容包括：本发明公开了一种拉矫机矫直低牌号无取向硅钢的方法,当焊缝达到拉矫机前面时,生产线的整体速度降低至28-32m/min、拉矫机的辊系辊缝全部打开同时辊系不接触钢带、拉矫机的延伸率降到0.08％-0.12％、拉矫机前后张力辊的压辊全部压下,焊缝通过拉矫机后,均恢复到正常水平。本发明的目的是提供一种拉矫机矫直低牌号无取向硅钢的方法,解决焊缝经过拉矫机时焊缝在拉矫机的拉伸矫直作用下发生断带的事故的问题。(The invention discloses a method for straightening low-grade non-oriented silicon steel by a tension leveler, when a welding line reaches the front of the tension leveler, the integral speed of a production line is reduced to 28-32m/min, roll gaps of roll systems of the tension leveler are all opened, the roll systems are not contacted with a steel strip, the elongation of the tension leveler is reduced to 0.08% -0.12%, press rolls of front and rear tension rolls of the tension leveler are all pressed down, and the welding line is restored to a normal level after passing through the tension leveler. The invention aims to provide a method for straightening low-grade non-oriented silicon steel by a tension leveler, which solves the problem that a welding seam has a broken belt under the tension straightening action of the tension leveler when the welding seam passes through the tension leveler.)

1. A method for straightening low-grade non-oriented silicon steel by a tension leveler is characterized by comprising the following steps: when the welding line reaches the front of the tension leveler, the integral speed of the production line is reduced to 28-32m/min, the roll system roll gaps of the tension leveler are all opened, the roll systems do not contact the steel strip, the elongation of the tension leveler is reduced to 0.08% -0.12%, the compression rollers of the front tension roller and the rear tension roller of the tension leveler are all pressed down, and the welding line is restored to the normal level after passing through the tension leveler.

2. The method for straightening low-grade non-oriented silicon steel by the withdrawal and straightening unit as claimed in claim 1, which is characterized in that: the overall speed of the production line was reduced to 30 m/min.

3. The method for straightening low-grade non-oriented silicon steel by the withdrawal and straightening unit as claimed in claim 1, which is characterized in that: the elongation of the withdrawal and straightening machine is reduced to 0.1 percent.

Technical Field

The invention relates to a method for straightening low-grade non-oriented silicon steel by a tension leveler.

Background

The acid rolling production line is a production line for changing hot rolling raw materials into cold rolled steel coils through transportation, uncoiling, head and tail straightening, welding, straightening, acid washing, trimming, rolling and coiling. The main process flow is that the hot rolled coil is transported from a raw material storage span to a cold rolling span walking beam. A steel coil outer diameter measuring device, a steel coil width detecting device and a steel coil weighing station are arranged on the walking beam, and after the steel coil outer diameter data are recorded, the coiling trolley automatically positions the hot-rolled coils to the corresponding mandrel heights of the uncoiler respectively. A centering device is also arranged for correcting the positional deviation of the steel coil. And conveying the centered steel coil to a carrier roller of the uncoiler, and manually removing the steel coil bundling belt on the carrier roller of the uncoiler. After the binding belt is removed, the rotating carrier roller rotates the head of the steel belt, and the head of the steel belt is fed into the uncoiler. The feeding action is realized by a carrier roller. By rotating the uncoiler in the opposite direction, the strip head is bent upwards. The pre-bending of the strip head can simplify the strip threading process through a straight head machine. After the steel coil is pre-bent, the walking beam conveyor conveys the steel coil to an uncoiler for uncoiling. And straightening the head and the tail of the steel strip by a straight head machine, welding by a welding machine, straightening the steel strip by a straightening machine, pickling by a pickling tank, rinsing by a rinsing tank, drying by a dryer, trimming and shearing edges, rolling by a rolling mill, and coiling by a coiling machine to obtain the qualified cold-rolled coil.

In order to ensure continuous and stable operation of a unit and good pickling effect, a tension leveler is generally arranged at an inlet of an acid tank, and the tension leveler has the main functions of scale breaking and tension leveling. The scale breaking is mainly to break iron scales, a compact iron oxide scale layer generally exists on the surface of the steel strip, the acid pickling effect is restricted by the compact iron scales, and the compact iron scales can be broken through reciprocating bending, so that the acid pickling effect is improved; the straightening and withdrawal mainly means that good plate shape is obtained, the problems of plate surface wave edges, wave shapes, buckling and the like are eliminated, the straightness of a steel plate can be greatly improved, the anisotropy of materials can be improved, and therefore the thickness of the plate is uniform. The tension leveler mainly realizes the functions of scale breaking and tension leveler through a certain elongation rate, and the elongation rate of the tension leveler is 3 percent at most in general conditions. The straightening and withdrawal machine is generally provided with a bending device, which mainly causes that if a tension roller is used for straightening strip steel, the tension generated by the tension roller exceeds the yield strength of the strip steel, a large amount of energy is consumed, the requirement on a transmission device is high, and the abrasion and failure rate of equipment is high. The bending function is to bend the strip steel on the roller, thereby greatly promoting the straightening effect. The tension leveler can simultaneously stretch and straighten the welding line in the process of straightening the steel strip, the strength and the toughness of the welding line are higher than those of the base metal under normal conditions, and the welding line cannot be influenced in the tension leveling process. On the contrary, once the strength and toughness of the welding seam can not meet the withdrawal and straightening requirements, the welding seam can be disconnected at the withdrawal and straightening machine, so that accidents occur, and the abnormal shutdown of the production line is caused.

One important variety of the products produced by cold rolling of the clad steel is medium and low grade non-oriented silicon steel, the medium and low grade non-oriented silicon steel is low carbon steel with the silicon content of 0.3-1.0%, and the welding performance of the low carbon steel is poorer than that of the low carbon steel due to the higher silicon content. When the mass fraction of silicon is less than 0.30%, the weldability is still good, but the weldability is significantly deteriorated as the silicon content increases. When the mass fraction of silicon reaches about 0.60%, the weldability is significantly deteriorated. Mainly because the silicon content of the medium and low grade non-oriented silicon steel is higher, a heat affected zone is easy to generate a hard and brittle martensite structure during welding, so that cold cracks are easy to generate. Therefore, the withdrawal and straightening unit needs to be properly adjusted at the position of the welding line to ensure the stable and smooth operation of the production line.

Disclosure of Invention

The invention aims to provide a method for straightening low-grade non-oriented silicon steel by a tension leveler, which solves the problem that a welding seam has a broken belt under the tension straightening action of the tension leveler when the welding seam passes through the tension leveler.

In order to solve the technical problems, the invention adopts the following technical scheme:

when a welding seam reaches the front of the tension leveler, the overall speed of a production line is reduced to 28-32m/min, roll gaps of roll systems of the tension leveler are all opened while the roll systems are not in contact with a steel strip, the elongation of the tension leveler is reduced to 0.08% -0.12%, the compression rollers of front and rear tension rollers of the tension leveler are all pressed down, and the welding seam is restored to a normal level after passing through the tension leveler.

Further, the overall speed of the production line was reduced to 30 m/min.

Further, the elongation of the withdrawal and straightening unit is reduced to 0.1%.

Compared with the prior art, the invention has the beneficial technical effects that:

in the process of straightening middle and low grade non-oriented silicon steel by the withdrawal straightening machine, the stable and smooth operation of the production line is effectively ensured by adopting the strategies of reducing the speed, the elongation and the roll gap and completely pressing down the front tension roll and the rear tension roll.

Drawings

The invention is further illustrated in the following description with reference to the drawings.

FIG. 1 is a layout view of a withdrawal and straightening unit and front and rear tension rolls.

FIG. 2 is a roller system diagram of a withdrawal and straightening unit.

Description of reference numerals: 1. a deviation rectifying roller; 2. a turning roll; 3. a front tension roller of a withdrawal and straightening machine; 4. a tension leveler roller system; 5. a rear tension roll of the tension leveler; 6. a pickling tank; 7. a roller box; 8. a bending roll of a withdrawal and straightening machine.

Detailed Description

The invention mainly provides a method for straightening low-grade and medium-grade non-oriented silicon steel by a tension leveler, which aims to avoid the accident that a weld joint is broken under the tension straightening action of the tension leveler when the weld joint passes through the tension leveler. The layout of the tension leveler and the front and rear tension rollers is shown in figure 1.

A method for straightening middle and low grade non-oriented silicon steel by a tension leveler comprises the following steps:

when the welding line reaches the front of the tension leveler, the overall speed of the production line is reduced to 30m/min, and the speed of the welding line is recovered to a normal level after the welding line passes through the tension leveler;

when the welding line reaches the front of the tension leveler, the roll gaps of the roll system of the tension leveler are all opened, the roll systems do not contact the steel strip, the roll gaps are restored to the normal level after the welding line passes through the tension leveler, and the roll system diagram of the tension leveler is shown in FIG. 2;

when the welding line reaches the front of the tension leveler, the elongation of the tension leveler is reduced to 0.1 percent, the deformation of the steel strip is reduced, the welding line smoothly passes through the tension leveler, and the elongation of the welding line is recovered to a normal level after the welding line passes through the tension leveler;

when the welding line reaches the front of the tension leveler, the compression rollers of the front tension roller and the rear tension roller of the tension leveler are all pressed down; after the welding seam passes through the tension leveler, the compression rollers of the front and rear tension rollers of the tension leveler are all opened, and the steel belt can be pressed in time when a belt breakage accident occurs, so that the accident loss is reduced.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.