SU1461554A1 - Size moulding roll - Google Patents

Abstract

The invention relates to the production of long products and pipe production. The purpose of the invention is to improve the quality of the tubular billet by providing a variable curvature of its profile in cross section. The calibrated forming roll is made with a curvilinear forming drum. At the same time, the perimeter of the roll profile is constant with a gradual increase in the caliber radius from the greatest penetration depth to the smallest. In addition, in the production of pipes from carbon steel grades, the radius of gauge g varies according to the law 10R - h sin у- Jh2sin2f + -180Rh + 80h2-20r sin4 / 4r 0, where R is the roll radius, h is the maximum depth of gauge, 1 - the length of the gauge profile, - the polar coordinate in the plane perpendicular to the axis of the roll. The depth of the gauge p of the calibrated roll is determined by the formula p.

Description

one

The invention relates to the production of long products and pipe production.

The purpose of the invention is to improve the quality of the tubular billet by providing a variable curvature of its profile in cross section.

FIG. 1 dan roll with constant radius of curvature of the caliber profile; in FIG. 2, a swath with a double radius KA3. 1 profile profile; in fig. 3 is a diagram for constructing a caliber profile J in FIG. 4 — caliber profile with constant radius of curvature} in FIG. 5 is a caliber profile with a double-radius calibration; in FIG. 6 is a graph of the function f P (f) presented in the claims.

When making a roll profile with a monotonous change in the radius g of gauge (Fig. 1, 2), the features of the continuous shaping of certain types of long products, in particular the production of welded pipes and profiles, are taken into account. As is well known, the production technology (molding) of the original billet in the local focus of one rolling (molding) roll is characterized by a necessary - a natural undesirable effect of springs of the finished molded profile out of contact with the roller, and with increasing distance from the axis of symmetry, the metal movement increases. Therefore, the known profile

The rolls, in which the radius of the gauge around the perimeter does not change, cannot provide a well-shaped preform. By making a roll profile with a variable radius, this undesirable effect is taken into account, and, together with the variable curvature of the gauge profile, the springing of the billet formed in this roll is significantly reduced.

The roller has a constant perimeter in any section and ensures the continuity of the shape of the tube billet.

The nature of the monotonous change in the radius of the gauge of the roll profile, This is achieved by a symmetric

warmly increasing the radius of curvature from the greatest depth of plunging of the caliber to the smallest, provides a gradual shaping of the geometrical parameters of the product and eliminates deformation peaks in different parts of the product, i.e. allows you to get quality products.

Theoretical and experimental

Studies have shown that the ratio of the maximum plunging depth, h to the minimum, equal to 1.25, is optimal in the absence of corrugation.

The bottom of the gauge is a circle of radius R — 0.9 h, offset from the center of the circle of the roll flanges by 0.1 h.

If the ordinate axis is directed through the points with the maximum depth of penetration and the minimum depth of penetration, and the center of coordinates is located in the center of the circumference of the flanges, then the depth of the caliber p depending on the angle (Fig. 3) can be determined as follows

in a way.

By the cosine theorem

CB2 AC2 + AB2 -2 ASAB cos ((f - |)

 АС2 + АВ2-2АСАВ sin if. From here

35 AB

2AC 4AC2sin2vf -4AC2 + 4CB2

since ab cannot be negative.

According to the foregoing, the CB R-0.9h,, 1h, where h is the maximum depth of the caliber.

Therefore, the dependence for AB takes the form

AC sinvp + VCB2-AC2 + AC2sin2tp ..

 0.1h 1kg - l, 8Rh + 0.81h2-0.01h4-0.01h sin 2ll205i zl§2Rh ± 80hi + hf sin2 Ф + h

  l --- - --- - - - - 1,

ten

Using an expression for AB, it is easy to get an expression for f

o 10R - h + lOOR -180Rh + 80h2. ., - vu

ten

in the manufacture of carbon steel pipes, the purpose of the invention

f R - AB;

is achieved at a constant radius of curvature along the caliber profile (Fig. 4).

We define the dependence for the change of the radius of curvature - r depending on the path of the simplest trigononetrichesky radius of curvature - r depending on j

bridges from the angle (since the depth of the transform (coso (1-2 sin2 | -) is not a function "f). The right-hand part of the expression can be half the angle, the segment stretching can be set as:

length

profile

 G (1 - COS -)

10R-h sinf - M100RZ-180Rh + 80h2 + h2sin2 (f -20r 0. (2)

The dependence of the width of the gauge h is easy to determine from geometric considerations

21 r2 (rr) 2 2pr.-p

n 2 l2 pr - p.

(3)

The specified construction of the roll profile provides the maximum permissible intensity of deformation of the peripheral sections of the strip in the cross section of the minimum profile radius and maximum caliber depth. Subsequent shaping reduces the intensity, since the radius of the profile

increases

, and this, in turn

gf - - - - - trr g-

allows you to unload (reduce the amount of longitudinal deformation) to the longitudinal fibers of the peripheral sections due to the proposed profile you can get such a reduced

+ 100R2-180Rh + 80h2

 51 - j OORj; h r.

a for radii significantly exceeding the depth of penetration

g

1012

80R - 8h sinvf- 8 jhZsinZ + 100R2-180Rh + SOh (5)

The construction of the caliber profile is illustrated in FIG. 3 - a roll section along the axis of symmetry. FIG. 3 A is the center of the coordinate system, I is the roll flange, II is the bottom curve of the caliber profile.

In the production of pipes from high-alloyed steel grades, experimental analysis showed the need for profiling the caliber according to a two-radius scheme, and the radius of the caliber in

I 2 g

4g

From here we get the desired relation for the radius of curvature

50

the magnitude of the forming radius in one section, which would be impossible with a constant roll profile. This will intensify the process.

0 moldings (bends) in each specific local deformation center and, at least on a borderline, to obtain the desired shape of the forming centers (deformations).

Such cyclic dependences of changes in the geometrical parameters of the roll profile imitate existing, real, local deformation points in the lines of the forming mills, along the profile of one roll.

These mathematical dependences for the radius of the gauge and the depth of penetration are not difficult for the workshop technologists to compile roll calibrations.

5 In this case, with a maximum depth of incision comparable to the radius of the caliber, a simplified formula can be used to calculate

+ 100R2-180Rh + 80h2

(four)

The region of its peripheral areas r 5Q is constant, and in the region of the bottom of the gauge r it changes according to a certain law in such a way that the tangents at the corner points of the profile are parallel.

gg. However, the length of the peripheral portions of profile 1 gradually increases from a value equal to

- with the greatest depth of incision.

71 to a value equal to Tg, with the least depth of incision according to the law 1

 -g (5 sinf + 9) (4), which provide s

-five

As shown by experiments, the kinematic folding conditions are optimal.

Using the illustration in FIG. 5, we obtain the dependence linking r and r.

As can be seen from figure 5, the difference is p. li - equal to the difference r -

T - 01

---- (p insertion depth of 2G2

by the formula (1) as well as for the single-radius scheme), i.e.

Я- r.sinii .fi4 or more in a simplified form

pr, sini 2r, sin

(five)

Similarly, using geometric relations, we can obtain the dependence for the balls of caliber ti

146t55A8

The perimeter of the roll gauge profile (1) is 64.3 MM, the maximum depth of the gauge (h) is 20 mm.

To compile a summary table. 1 use the nomogram (FIG. 6) and formulas (1), (2), (3).

EXAMPLE 2. In the production of carbon steel pipes with a diameter of 100 mm and a wall thickness of 3 mm in the mill. Gabirtny sizes: diameter on roll flanges (2R) - 240 mm; swath width (M) - 180 mm; perimeter of the roll profile (1) - 158 mm;

15 The maximum depth of the caliber (h) is 50 mm.

To compile a summary table. 2 use the nomogram (FIG. 6) and formulas (1), (2), (3).

20 The use of a calibrated molding roll allows the control (regulation) of specified billet properties by providing variable curvature of the profiles along the perimeter, as well as obtaining optimal geometric parameters for the casting caliber when producing pipes from carbon and high alloy steels.

thirty

(G2 - G) 2 - () 2+ 2G P,

OR

P 2g, + | 2g.- |) H 2g, g,

 2g, -b (r-.g,) (2g ,, -g, -r)

(6)

Application of a two-radius caliber35

Formula inventions

Claims (3)

1. Calibrated forming roll with a curved barrel forming, characterized in that in order to increase the quality of the pipe billet due to the perpendicular curvature of its profile in cross section, it is designed to produce pipes from high perimeter gauge profiles from symmetrically alloyed steel grades, ensuring minimal unbalancing the curvature radius from the maximum depth of the IC and the minimum bending of the 1st moment. plunge caliber to the smallest. 2. The molding roll according to claim 1, wherein m is the fact that, with the goal of obtaining optimal geometrical parameters of the roll gauge for the production of pipes from carbon steel grades, the radius of the gauge g 50 varies according to the law tubular billet. Example 1. In the production of carbon steel pipes with a diameter of 40 mm and a wall thickness of 1 mm in the mill 20-12. Dimensions: roll flange diameter (2R) - 160 mm; roll width (M) - 75 mm;     t 10R - h | h sin2vp + 100R -180Rh + SOh - 20r 0, where R is the roll radius h - maximum caliber depth} 1 - length profile caliber f - polar coordinate in plane55 bones, perpendicular axis roll  the depth of the gauge f of the calibrated roll is determined by the formula 9146155410 10R - h sinvp- l hzsinzvl + 100R2r180Rh + SOh P in,. „,.“ ™ - - -. - --- - - --- - - - G - - 10 -five I a is the width of the calibration gauge, and the radius rj varies with n 2 S / 2fP 3. The forming roll according to claim 1, p-sin-2T i sin -r is Z different in that,. in order to obtain an optimal geo- 1. + 9) - the length of the partial parameters of the roller caliber for the production of pipes from a high caliber profile with a constant alloyed steel grades using an –is radius of curvature g, while the two-radius calibration is deep, and the gauge of the roll profile is determined by the radius of curvature of the gauge profile g - Fi9,2 FIG. g 8h Fi.Z FIG. k f / l g 0 .3-0.8-0 0.7 0.6  ABOUT L- / 7g / g zl- / "gg 5 - / g - / g 7 - /" gzh g qOt / e.f 5