SU1592065A1 - Back-up rolling mill roll - Google Patents

Description

The invention relates to the processing of metals by pressure, namely, sheet-rolling production, and can be used in the production of strips and sheets on broadband hot rolling mills. The purpose of the invention is to increase the durability of the support

The invention relates to the processing of metals by pressure, namely, sheet-rolling production, and can be used, for example, in the production of strips and sheets on broadband hot rolling machines (SHSGP).

The purpose of the invention is to increase the resistance of the support rolls, by reducing the stress concentrators in the transition of the neck to the barrel.

The support mill roll has, on the edges on its outer surface, annular grooves 1.1-1.3 wide grooves depth, while the pair of annular grooves between the generatrix

2

rolls by reducing the stress concentrators at the junction of the neck · · to the barrel. The roll includes a barrel and a neck with a transitional area in the form of an end surface with an annular groove made on it and stepped outer portions adjacent to the end of the roll barrel, on the outer surface of which there are annular grooves with a width of 1.1-1.3 depth of the groove . When this pair of annular grooves between the generator and the end surface is made with a radius of 3-6 smaller radii K ₁ mates on the end groove, and the height of the groove is determined from _a mathematical expression. Such a koi- ® structure reduces the consumption of rolls per ton of rolled metal, reduces the cost of regrinding defective support rolls, reduces the downtime of the mill for transshipment. 2 Il. 1 tab.

and the end surface is made with a radius of 3-6 smaller radii of the pair on the end groove, and the height of the groove is determined from the expression

¹¹¹

W- ° n ⁾ '

where N is the height of the annular groove, mm;

a - a constant that determines the minimum height of the groove at the end of the campaign for the operation of the support roll, and is equal to 2 mm;

B is a constant that determines the maximum height of the groove in

the beginning of the campaign operation

the support roll, and is equal to 15 mm;

ЗЦ 1592065 А1

1592065

ϋ - the current diameter of the roll barrel, mm;

Э _п - minimum permissible dia- meter of the roll barrel, mm;

P _o is the initial diameter of the roll barrel, mm; ha is an exponent depending on the nature of the wear of the surface of the roll barrel, the size of the mill addendum, the profiling and the mill assortment (0.3 <m ^ 3).

FIG. 1 shows schematically the proposed device, a general view; in fig. 2 — node I in FIG. 1 (end portion of the longitudinal section of the barrel).

The support mill roll consists of necks 1 and a barrel 2 with an end surface on which an annular groove 3 is made with a depth of 1, with a smaller radius of 20 mating bottom and walls K ,.

On the outer surface of the barrel 2 there is an annular groove with a width of 1 ₂ = = (1.1-1.3) 1 ^ and height b = a + b (^ ---) ^,

in this case, the conjugation radii of the annular groove and the end surface = K ₃ = (3-6) K ₁ , where b is the height of the stepped annular groove; a is a constant that determines the minimum height of the groove at the end of the operation campaign for the support roll; B is a constant that determines the maximum height H of the groove at the beginning of the operation campaign for the support roll; Ώ - the current diameter of the barrel 2 roll; ϋ _η “minimum, ³³

the allowable diameter of the barrel 2 roll; ϋ ₀ - the initial diameter of the barrel 2 roll; W - exponent, depending on the nature of the wear surface of the barrel 2 of the roll, the size of the mill, profiling and the range of the mill (0.3 W 3).

Support mill roll works as follows.

The roll enters the rolling stand 45 of the quarterstep group SHSGP, where the proposed support rolls are paired together with the workers. In the inter-roll gap of the work rolls, the roll is subjected to deformation. In this case, the work rolls • bend and, acting on the supporting rolls, thereby subject them to bending.

In the critical sections (sections ··. Of the neck-to-barrel transition), minor concentrators of pressure build up, for which annular grooves 3 are made in these sections, which reduce the likelihood of the rolls breaking. When the strip leaves the roll gap, the work rolls that are in a tense (curved) state are aligned by acting on the end sections of the barrel of the support rolls, which are thus not subjected to shock loads.

The essence of the proposed roll is that during operation it is subjected to bending load and in sections of critical sections (places of junction of the necks of the roll to the end of the barrel). stress concentrators occur. To prevent this, the stepped sections in the form of annular grooves are made on the surface of the roll barrel, which reduces respectively the load on the end, sections of the barrel of the support roll and increases its durability. Thus, the essence of the proposed roll consists in removing stress concentrators' in critical sections and reducing the load on the end sections of the barrel of the support roll. When this stepped outer area on the surface of the barrel is made in the form of an annular groove with a width equal to 1.1-1.3 depth end grooves, and the pair of annular grooves between forming the barrel and the end surface is made with a radius equal to 3-6 smaller conjugation radii face groove. The height of the groove is determined from the expression

• b = a + b (

ϋ-ϋ η \ "o-0 ~ l

IL

The exponent is chosen in the range of 0.3 <w ίΌ, Ο. It depends on the nature of the wear of the surface of the roll barrel, the profiling and the range of the mill. So, its large values up to w £ 3 should be used with increased depth of profiling (a concave barrel of the working rolls) and with increased widths of rolled strips in the mill assortment. A further increase in w> 3 is undesirable, since it leads to an unnecessary decrease in the height of the stepped outer sections, which contributes to the increase and redistribution of loads on the end sections of the support rolls and leads to the destruction of these sections, thereby reducing the overall resistance of the rolls. Smaller values of the I index of degree up to g0.3 are advisable to assign in the event that

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when the backup rolls are used in the middle group of stands of the finishing group of the mill, where the wear for the campaign is large enough and the resource of the support roll is close to the limit, i.e. the value of the current roll diameter (I) is close to the maximum permissible value, i.e. (ϋ-Ο_ο) - * 0. A further decrease in the exponent ha ^ 0.3 is undesirable, since this significantly increases the height of the stepped outer sections on the surface of the roll barrel with a minimum resource reserve and when rolling steel grades with increased other-healthy, a significant increase in pressure of the work rolls on the support rolls destruction of the step transition, which affects the increased wear of the work rolls, and, consequently, leads to a decrease in their durability. The width of the annular groove on the outer surface of the roll barrel is 1.1 <1₂/

/ 1-, 1.3 depth of groove. This is due to the fact that when the width of the groove 25 smaller than the necks February _{1/1 1} <1,1 groove depth occurs already marked attenuation of end portions of the roll barrel minutes even with a slight increase in the pressure of the working rolls on the bearing may be destroyed zo these sites. "Increasing the groove width more than 1 ₂ / / 1.71.3 of the depth of the groove is also impractical, because when rolling the rolls are subjected to bending load and with a significant decrease in the length of contact between the work rolls and the support rolls, there is a significant increase in contact stresses which can lead to breakage of the support rolls of 4θ.The radius of junction of the annular groove is 3-6 smaller than the radii of conjugation of surfaces on the end groove 3 4К ₂ / К, ^ 6. This value is due to the fact that less K ₂ / K ₁ <3 on the face groove in places of stepped outer sections may increase stress concentrators, which reduce the rolls durability. 50 Increasing this radius, i.e. K ₂ / K>

> 6, leads to a redistribution of concentration. rators of stresses and reduce the effect obtained from creating a stepped 55 sections on the outer surface of the roll, since the width of the annular groove is significantly reduced, which ultimately leads to a decrease in the strength of the end sections of the barrel.

When choosing the limits of the second radius of conjugation, i.e. 3 ^ P ^ / P, <6, it should be assumed that smaller values are rational at the end of the campaign of the support rolls, and large values - at their beginning. If you choose P ₃ / K, <3, then even at the end of the campaign, the crumble on the roll barrel increases, and as these boundary values increase, for example, K ₃ / K ₍ ? 6, even at the beginning of the support roll campaign, the contact stresses between support and working roll, and this ultimately "affects the cyclic resistance of the roll and therefore irrational.

Example. As an example of the execution, comparative rolling strips on the SGP 1700 using the known and proposed types of rolls (Table 1) can be given. Control of comparative tests carried out during the four campaigns support rolls. Each campaign lasts about two weeks in accordance with the accepted volume. Every time control is carried out on 14 support rolls. Under the crumbs on the edge of the barrel they take: chips and crap, ^and ki adjacent to the end of the roll barrel; and on the surface of the barrel - those of them that do not extend beyond the middle section of the barrel with a length of 96% of the total length, · Also the area spent for chipping the rolls is also recorded.

The value of the height of the annular groove is determined from the expression

B = a + b ("- ®-) ^t . ^and o ^and l

Values of roll diameters (maximum and minimum) are chosen in accordance with the technological instruction: ϋ _β = 1500 mm; ϋ _η = 1450 mm. The current size of the diameter of the roll ϋ = 1475 mm. The constants determining the permissible values of the height of the annular groove: a = 2 mm - based on the effectiveness of this groove, which disappears with a further decrease; B - 15 mm, which is determined by the strength of the roll in the area of the groove

, _o s / 1475-14504 o, s,,

^{2 + 15} ^ 1500-1450 ^ ¹⁴

ι. η,. from 11475- 1450k ι ι \

^Η v ⁼ 2 + 1.5 (· ^ _5θ θ _{= 14} ξ ₀ ) -7 (mm)

ν ", _from D47 5-1450 _h zo,, \

2 + 15 (“- θ _Σ - ₄ ξθ) '3 (mm).

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Technical and economic benefits of the proposed roll consist in reducing the consumption of rolls per ton of rolled metal; reducing the cost of regrinding of defective backup rolls; reducing mill downtime for handling emergency backup rolls.

Claims (1)

Claim groove width 1.1-1.3 depth of the groove, while the pair of annular grooves between the generator and the end surface is made with a radius of 3-6 smaller radii of pairing on the end groove, and the height b of the groove is determined from the expression B = a + b ( ϋ-ϋ _p _h The support mill roll mainly for the quarters' quarters of the wide-band hot mill of Lokrokat, containing a barrel and a neck with a transitional section in the form of an end surface with an annular groove, characterized in that, in order to increase the durability of the support ₂ rolls by removing stress concentrators at the neck transition points barrel, on the edges of the barrel on its outer surface are annular 'where a is the minimum height of the groove, mm; L is the maximum height of the groove, mm; B - the current diameter of the roll barrel, mm; ϋ _η - the minimum allowable diameter of the roll barrel, mm; ϋφ - the initial diameter of the barrel shaft · ka, mm ;. w - exponent equal to 0.3 <3. Roll type Ring groove width, 1 _g , mm Depth of groove, 1 ₍ mm 1ι / 1, Radius of junction of the groove, K ₂ = K ₃ , mm Groove coupling radius K, mm k ₂ / n, 'N, mm and - 50 - - five - - P, 55 50 S 15 five 3 3 P. 60 50 1.2 20 five four 7 P ί 65 50 1,3 thirty five 6 14 Table continuation Roll type Chips on rolls pcs. ..but On the surface- On the edge, the ness of the barrel barrels , Total area - chips mm ² The average time ne, repshifovki roll, min Roll consumption per ton of rolled metal, kg / t AND P P P - 6 87500 275 0.1 one four 75060 265 0.096 one - 21900 224 0.091 five one 82210 258 0.095 1592065