SU1148658A1 - Method of hot rolling in nonreversing universal stand - Google Patents

Abstract

1. METHOD OF FIELDING ROLLING IN NON-REVERSE UNIVERSAL CELL, a predominantly continuous broadband mill, including simultaneous crimping of the roll by vertical and horizontal rollers located in different planes, characterized in that, in order to reduce the dynamic loads during pick-up of the roll, horizontal rolls are used to pick blanks, in the sections, under the chaps, the razors of the chases, 1. , the front end of the roll is folded down at the exit of the vertical rolls in a vertical plane from the rolling line and in this position they are inserted into the contact t with one of the horizontal rolls, outside the deformation zone of the established rolling process, and then the limb force is removed after the metal is gripped (/) by the horizontal rolls. NU 00 with: l eo

Description

2. A method according to claim 1, in which the bending is carried out by turning the axes of the vertical rolls in a position inclined to the rolling direction.

3. The method of pop, 1, differs (the fact that the bend is carried out by moving the guiding device located in the area between the vertical and horizontal rollers.

The invention relates to rolling production and can be used for hot rolling in non-reversible universal cages, mainly in the roughing line of continuous broadband mills. On continuous broadband mills, rough rolling is carried out in non-reversible universal cages, in the main line of which there are significant gaps, especially due to the use of universal spindles, which leads to a multiple increase in the dynamic moment of rolling during the capture of hot rolled strip (3-4 times) and adversely affects the durability of the mill equipment,. The known method of hot rolling when in order to reduce the dynamic loads during the capture of metal, the front end of the roll gives a pointed or other shape, facilitating the capture of 1J. However, to implement this method, additional equipment is needed, while the expenditure ratio increases. To the proposed is a method of hot rolling in the non-reversed universal stand of a predominantly wide-strip mill, including the simultaneous compression of the roll vertical and horizontal rollers C arranged in different planes. The ratio of the speeds of the vertical and horizontal rolls in these cages is chosen so as to ensure a minimum of dynamic loads in the cage when the strip is captured. However, this does not provide a sample of the esopes in the main line of the stand, which leads to dynamic shock loads in the main line of the stand. The purpose of the invention is to reduce the dynamic loads during the capture of the roll by horizontal rolls by sampling gaps in the main line of the stand. The goal is achieved by the fact that according to the method of hot rolling in an irreversible universal stand of a predominantly continuous broadband mill, including simultaneous compression of the roll, vertical and horizontal rolls located in different planes, the front end of the roll is bent at the exit of the vertical rolls in the vertical plane from the rolling line and in this position, it is brought into contact with one of the horizontal rolls, outside the limits of the deformation zone of the established rolling process, and It relieves the limb force after the metal is gripped by horizontal rollers. In addition, the bend is performed by rotating the axes of the vertical rolls in a position inclined to the rolling direction. Moreover, the bend is carried out by moving the guide device located in the area between the vertical and horizontal rollers. FIG. 1 shows a scheme for implementing the method and the forces acting therewith; in fig. 2 is a diagram of the implementation of the method of the axes of the vertical rolls in a position inclined to the rolling direction; in fig. 3 - the same with a guide device; in fig. And - the scheme of the main, line of the cage. Hot rolling of roll 1 is carried out in a universal non-reversing stand containing two vertical rolls 2 and two horizontal rolls — the upper 3 n lower D. Vertical rolls 2 can be equipped with a mechanism for simultaneously turning their axes into an inclined position to the rolling direction. In the area between the vertical 2 and horizontal 3 and 4 rollers, a guiding device 5 can be mounted, which can be moved vertically. In this case, the vertical rolls 2 do not provide a reversal mechanism. The device 5 is made in the form of a pair of rollers (Fig. 3), either in the form of a support roller (upper or lower, depending on the adopted deviation direction), or in the form of a support movable plate. The choice of the design of the device 5 is not fundamental in the implementation of the proposed method of sharks rolling. At the same time, the arrangement of the device 5 relative to the horizontal rolls (distance C, Fig. 3) and the expediency of using the rotation of 25 vertical rolls 2 instead of using the device 5 is determined by nap meters rolled in the corresponding stand of the roll and the distance between the horizontal and vertical rollers (Fig. 3) where t is the yield strength of the material of the roll under the appropriate -3 conditions of rolling in the cage; ° moment of resistance of the cross-section of roll to transverse bending of B Рсо5Ыт Т StnOt-j-force of bending RiT is normal and the tangential force arising at the contact of the front end of the roll with the roller; B — projections onto the horizontal axis of the distance between the axis of the vertical rolls and the point of meeting the front end of the roll with the horizontal roller. The condition (2) bends the roll in a vertical plane and, supporting it until it comes in contact with one of the horizontal rolls of an wasp: is realized by turning the vertical rolls 2 in a plane parallel to the direction of rolling by angle p, (Fig. 2). In other cases, the bending of the roll in the vertical plane and its support are performed using the guide device 5, the location of which relative to the horizontal rolls (Fig. 3) is determined by the expression (1). The main line of the rolling stand contains (Fig. 4) a stand with horizontal rollers 3, and 4, the upper and lower chains of the main line, including universal spindles 6 and 7, gear stand 8 and the electric motor 9. The method is carried out as follows. Hot roll 1 (Fig. 1) enters the vertical rolls 2 and after leaving them its front end is bent in a vertical plane from the rolling level so that it occupies position I or 1. In this case, the accepted direction of the specified bend of the roll (up or down I) is fully defined by the cage design. However, preference is given to bending the roll upward from the rolling level, as it is simpler to implement, therefore, below we will analyze this variant of the method implementation. In the specified curved position, the front end of the roll is brought into contact with the upper horizontal roller 3 outside the deformation zone, i.e., where 0 is the angle of metal gripping by the rollers; the angle of the beginning of contact of the front end of a curved bar with a horizontal roller (Fig. 1). Beginning from the moment of bending of roll 1 in a vertical plane, bringing its front end into contact with the upper horizontal roller 3 and up to the subsequent gripping of the metal by horizontal rollers 3 and 4, the bar is held in a bent position with the help of respectively unfolded vertical rolls 2 (if the condition is met (2 ) or guiding device 5 when the condition {O. is satisfied. As soon as metal is caught by the rolls (filling of the deformation stage), support of the roll is stopped. From the beginning of the input of the front end I will bend The first roll into contact J with the upper horizontal roller 3, in contact a force 8 (Fig. 1) arises, the magnitude of which is due to the need; the roll bend in a vertical plane relative to the support: vertical rolls 2 or guide device 5. At the same time roll 1 vertical rollers 2 are continuously fed to the horizontal rolls 3 and 4 at a speed slightly lower than the horizontal linear speed component of the surface of the rotary rolls of the horizontal rolls. This eliminates, on the one hand, the occurrence of undesirable in this case support forces, on the other hand, the need to strictly fulfill the condition where is the angle of friction in contact of the roll with the horizontal rollers. Starting from the moment when the front end of the roll 1 is brought into contact with the upper horizontal roller 3, there arises a braking moment of this roll, which is equal to (Fig. 1). . M. coset - -jUS not where (U. is the coefficient of friction, R is the radius of the horizontal roll. Simultaneously, the roll braking time is the nodal deceleration of the roll. J is the moment of inertia; GD is the poppy roll moment divided by B; e is the linear deceleration of the roll% - acceleration of the free fall of. Equalities (3) and (4) follow. Gfcosot -t-jU. sinoC j There are always gaps in the main line of the stand (Fig. 4) and especially in its spindle x 6 and 7. Specifications in equation (5) by deceleration, these gaps are chosen before the beginning of the moment when the metal is gripped by the horizontal rolls 3 and, moreover, the guaranteed selection of gaps has If the condition is, the clearance in the upper chain of the main line, considered relative to the radius of the wave R; the path traveled by the outer surface of the universal spindle fork during deceleration of the horizontal roll 3, considered relative to the radius of the roll E., the same, the roll blade. -5c, part (5) we obtain o (G, (coSo (.4.jU.Sin b is the length of the capture arc (Fig. T); f is the continuity of the deceleration of roll 3; V is the speed of rotation of the roll. Ages (1) and (9) and FIG. 1 that 2СГЙ (с050 т К-5; п (/ 1т-) By bringing the front end of a bent roll into contact with a horizontal roller 3 outside the deformation zone and supporting the roll at a distance C selected according to expression (10), ensure that the condition ( 6), i.e., the gaps in one of the chains (in this case, the top) of the main line of the stand are completely selected.The top 6 and bottom 7. chains of the main line of the stand are rigidly connected through the gear stand 8 and form a closed system (Fig. 4 Therefore, sampling the floor gap in one of the chains of the main line inevitably leads to its selection y, even if incomplete, in another, which reduces the dynamism (arising dynamic loads) of the system under consideration. P. measure 1: In the first roughing stand of a continuous wide-strip hot rolling mill, a slab width of 1100 MI and thickness 260 mm thickness 220 mm out

steel 08KP. This is the smallest cross-sectional size of the rolled slab, and 08KP steel has the least resistance to deformation among the steels rolled in this stand. The rolling temperature is 1250 ° C, the rolling speed is 1 m / s, the friction coefficient is 0.35. The rolling stand is equipped with horizontal rolls with a diameter of 1,400 mm, the vertical rolls are installed at a distance of 3000 mm from the axis of the horizontal rolls. The weight of the horizontal rolls is 35.1 tons. In the hinges of universal spindles a gap of 4 mm is allowed.

Thus, they have the following parameters required in the calculations:, o, 1 & tSm -,

oi c (rccos (l-- j 13 ° H; & t - 2 - fO kg / m; - 1 & t, - m) After leaving the vertical rolls, b be bent so that it comes into contact with the upper Then, according to the formula (8), the deceleration time of the upper horizontal L is 0.08 s. From the formula (9) it follows that under the above conditions of rolling in the stand, the required bending force of the Q 7 - (-f.feT. To ensure the horizontal roll braking time required to close the gap in the chain of the main line of the stand, according to expression (10), the distance C to the support mechanism is taken ci 3.2 / and. In this case, condition (2) is fulfilled, the front end of the slab is bent by turning vertical sticks. Example 2. In the last draft stand of a continuous wide-width hot rolling mill, a roll is cut to a width of 1100 mm and a thickness of 80 mm by thickness 40 mm

from steel 08KP. These are the smallest cross-sectional dimensions of the rolled metal and steel. OVCP has the lowest resistance to deformation among

steels rolled in this cage. Rolling temperature 1150С, rolling speed 5 m / s, friction coefficient 0.3. The rolling stand is equipped with horizontal rolls with a diameter

1150 mm, vertical rolls are installed at a distance of 2800 mm from the axis of horizontal rolls. The weight of the horizontal rolls is 25 tons. In the hinges of universal spindles are allowed

4 mm gap.

Thus, they have the following parameters required for calculating fRAT 0, m;

nor x:

(, i

o "rcco5 (g 4 - (about bJl-r 1.7b.to-m) After exiting the vertical rolls, the roll is bent upward so that it comes into contact with the upper horizontal roll at 0-20 (0.349). According to the formula (8 ) the braking time of the upper horizontal roll is 0.02 s. From formula (9) it follows that, under the above conditions of rolling in the stand, the necessary force of bending of the roll should be 15-1.3 g. To ensure the braking torque of the horizontal roll required to close the gap in the chain of the main line of the stand, according to the extrusion (10) distance C to the support mechanism C 0544 m. Since in this case the condition (2) is not fulfilled, the slab is bent by the guide device 5 (Fig. 3), the method allows to significantly reduce the dynamic loads in the main lines of roughing mills of wide-strip mills, to increase durability of equipment.

J

Fi.2

Fig.Z

Claims (3)

1. The method of hot rolling in a non-reversible universal cage of a predominantly continuous wide-strip mill, including the simultaneous compression of the roll by vertical and horizontal rolls located in different planes, characterized in that, in order to reduce dynamic loads when the roll is gripped by horizontal rolls by selecting gaps in the main line crates, the front end of the roll is bent at the exit of the vertical rolls in a vertical plane from the rolling line and in this position it is brought into contact with one them from the horizontal rolls, outside roll gap steady rolling process, and 'then bending force is removed after the metal gripping horizontal rolls. SU.,., 1148658 2. The method according to π. 1, with the fact that the bending is carried out by turning the axes of the vertical rolls to a position inclined with respect to the rolling direction. 3. The method of pop. 1, characterized by: with the fact that the bending is carried out by moving the guide device located on the site between the vertical and horizontal rolls.