KR870001775B1 - Method for manufacture of steel wire & steel rod - Google Patents

Abstract

In a steel wire and rod rolling process using plane rolls, the roll bite of each roll pair is controlled so that width; thickness ratio of the rectangular section blank, after passage through the bite, is less than 1.5 Alternatively, or in addn, relatively small dia. rolls are used in which the roll dia. roll gap ratio D/H is no greater than(100/H)+5. Also claimed are roll guides for use in the process. The process provides stable rolling method using plane rolls, in which the wire or rod is deformed almost exclusively in the rolling direction without increase in width.

Description

Steel bar and steel wire manufacturing method

1 is a schematic illustration of various calibers used for steel bar rolling.

2 is a schematic explanatory diagram of a series of rolling mills for simplifying conventional caliber rolling.

3 is an explanatory diagram of a pass schedule for rolling steel bars or steel wires with caliber rolls and caliber rolls.

4 is a graph showing the main causes of reversal during caliber roll-free rolling.

5 is a graph showing the main cause of swelling on the free surface of a blank material.

6 is a schematic elevation of caliber roll rolling.

7 is an explanatory diagram of various dimensions for calculating the aspect ratio of the blank material immediately after rolling.

8 is an explanatory diagram of torsion occurrence of a blank material.

9 is an explanatory diagram of reversal occurrence of a blank material.

10 is a graph for explaining the relationship between pseudo-renew and reversal of blank material.

11 is a view of formation of a double-layer barrel.

12 shows the formation of a single barrel.

13 is an explanatory view of a practical example of a series of continuous rolling mills.

14 is a graph showing the relationship between roll diameter and stretching.

FIG. 15 is a graph illustrating conditions for obtaining drawing efficiency in a grooveless roll equivalent to that in a caliber roll.

16 is a perspective view of an adopted embodiment of a side guide according to the present invention.

17 (a) and 7 (b) are elevation views illustrating inlet guides for guiding a blank material in conventional caliber rolls and caliber roll rolling.

18 is a perspective view showing a defect in the rear end of the material to be rolled.

FIG. 19 is a perspective view showing a fin due to the defect shown in FIG. 18; FIG.

20 is a cross-sectional view showing adverse effects of defects in caliber rolling.

21 is a cross-sectional view perpendicular to the roll side illustrating the basic configuration of the inlet guide according to the present invention.

FIG. 22 is a cross-sectional view parallel to the roller axis illustrating a guide having the same configuration as that shown in FIG.

Fig. 23 is an explanatory diagram of the torsion at the front end of the rolled blank material;

24 (a) and 24 (b) are plan and side views of an embodiment of the inlet guide 1 according to the invention.

FIG. 25 is a perspective view of the inlet guide shown in FIGS. 24 (a) and 24 (b).

FIG. 26 is an exploded perspective view of the inlet guide shown in FIG. 25. FIG.

27 (a) is a cross-sectional view illustrating a small inversion angle according to the present invention.

27 (b) is a cross-sectional view illustrating a large reverse angle in conventional rolling.

28 is a graph comparing the pin length at the rear end of the rod and the inlet guide according to the present invention having a conventional guide.

29 is a plan view of one example of a series of rolling mills for carrying out the rolling method according to the present invention.

30 is an explanatory diagram of a pass schedule for the rolling method according to the present invention.

31 is an explanatory diagram of a pass schedule for conventional caliber rolling.

32 is an explanatory diagram of a pass schedule for caliber-free rolling in the prior art.

The present invention is a method for rolling a grooved rolled steel rod and steel wire, in particular for supporting the side of the rod in order to improve the grooveless rolling property, for rolling the grooved rolled steel rod to guide the rod between the roll gap It relates to a rolling method.

As used herein, the term " steel rods " refers to elongated metal rods and wires having a cross section such as square, square or circle of steel and nonferrous materials.

And the term " no groove roll " or " caliber roll free " means a roll having no caliber formed in the barrel.

Only caliber rolls have been used in the rolling of blank materials having a square cross section to produce steel bars, wires, etc. having a rectangular or circular cross section. In FIG. 1 illustrating a typical pass schedule, the blank material W having a square cross section is substantially the same as described above to obtain a square cross section steel P after being rolled once or several times through square or parallelogram calibers s and d. It is rolled through a shaped caliber or optionally through elliptical and circular calibers o and r to obtain a circular cross section steel P '. In this case, the material is generally subjected to continuous rolling so that a continuous series of rolling mills M ₁ , M ₂ , M ₃ ,... … Pass one pass to each rolling of M _n .

The number of roll stands suitable for rolling in a continuous series of rolling mills including caliber rolls is determined by the cross section of the insulator and the dimensions of the largest product. For example, if a circular cross-section rod with an outer diameter of 20 mm is produced from a blank cross section of square cross-section having a side of 145 mm, it requires six coarse, intermediate and trimming roll stans each containing a roll having a caliber as shown in FIG. do. Rolling of such caliber rollers faces the following problems.

(1) When a set of calibers is moved from its alignment position or the center of the guide means for introducing the material to be rolled into the caliber and the center of the caliber are moved to each other, a protrusion in the form of a fin is placed on the material in its longitudinal direction sent out from the caliber. Occurs, it impinges on the next rolling and causes defects such as overlap on the surface of the rod.

(2) In order to avoid the above defects, the rolls and the guide means must be correctly installed, which requires waiting time.

(3) Since the accuracy of the shape and dimensions of the caliber is considerably related to the quality of the product, high technology and expensive roll lathes are required to process the caliber rolls.

(4) Since the difference in the circumferential speed between each caliber causes irregular wear, the roll must be frequently processed to correct the caliber, which increases the cost.

(5) When the size of the rod to be rolled is changed (for example, the outer diameter of the sectional rod from 16 mm to 40 mm), many caliber rolls must be changed and increase the downtime of the rolling mill. One set of caliber rolls cannot be used over a wide range of rod sizes to be rolled.

(6) When the gap between a set of caliber rolls becomes smaller than a predetermined value, a protrusion occurs on the surface of the rolled material, which then collides with the next rolling operation to form a defect such as an overlap on the surface.

(7) Since there is a risk of breaking as the diameter of the caliber decreases, the roll is required to have a large diameter at first so as not to break at the caliber.

In order to avoid the above drawback of caliber rolling, a rolling method using two caliber rolls has been proposed, in which the blank material is rolled by caliber rolls, mainly for the purpose of reducing the cross-sectional area of the rod, and also in order to obtain the final shape of the product. Rolled by. Figure 3 illustrates the basic pass schedule of the method, where the caliber rolls are used for the upstream pass μ and the intermediate pass m just before the forming pass and the caliber rolls for the forming pass f.

If caliber rolls are used instead of caliber rolls, no caliber machining is required and the damage and wear on the surface of the caliber rolls is less than that of the caliber rolls, prolonging the roll life and changing the shape and size of the product to be rolled. No downtime is required, so the downtime is short and cheap. However, caliber rollers have the following drawbacks.

(1) Since no caliber roll has no caliber, the material is not limited in the width direction, so that the elongation of the material in the rolling direction is smaller than that of the caliber roll. The deceleration must be increased to obtain stretching of the material in the rolling direction substantially equivalent to that of the caliber rolls. However, the increased reduction increases the flat ratio, which is defined as Bo / Ho shown in FIG. Because of the angular flatness, the cross section of the material is inaccurately deformed on the next no-caliber roll path in FIG. 4, so the inversion a / H increases with the flatness ratio Bo / Ho, making it impossible to continue rolling.

(2) When the reduction is quite large, the free surface of the material not in contact with the roll becomes convex as shown in FIG. If the block rate limited to b / Ho is too large, the inversion a / H becomes large so that the next rolling cannot be performed.

(3) When the existing rolling equipment is changed from caliber rolling to caliber rolling pass, the number of passes must be increased because of less stretching in the rolling direction of the material, reducing the productivity of the device and increasing the number of roll stands of the continuous rolling mill. Let's do it.

It is an object of the present invention to provide a steel rod by means of a grooveless roll in a rolling process to reduce the cross-sectional area of the rods and wires, not a forming process for obtaining the final shape of the rods and wires to achieve stable rolling by grooveless rolls. It is to provide an improved method for rolling wires.

In order to achieve this object, a method of rolling steel rods and wires by passing rectangular cross-section blank material through a plurality of sets of grooveless rolls of a series of continuous rolling mills according to the present invention is directed to the shortened portion of the blank material cross section passing through the pole. And setting the clearance of each grooveless roll so that the ratio of the long side is kept smaller than 1.5.

Another object of the present invention is to provide a method for rolling steel bars and wires by grooveless rolls to obtain high drawing efficiency which makes rolling stable.

+5인 관계가 되도록 상당히 작음으로써, 가능한한 많이 압연 방향으로 블랭크재를 변형시킨다.To this end, according to the present invention, the diameter of each grooveless roll is such that the ratio of the diameter D to the gap H is D / H.

By being considerably small so as to have a relationship of +5, the blank material is deformed in the rolling direction as much as possible.

It is an object of the present invention to provide a guide for supporting the side of a rolled steel bar, which has a defined rolling zone having a predetermined width in the gap between the rolls to realize grooveless rolling without reversing and twisting the steel bar.

To achieve this object, a cylindrical cylinder is formed to surround a set of rolls in its front and rear rises to form a limited rolling zone, which is divided by a guide-rolled guide frame for rolling rods in accordance with the present invention and side by side along the roll barrel. It has the whole and back rolling guide joined to each other in the clearance gap between a set of rolling rolls with a surface barrel.

For this purpose, the guides as grooveless roll inlet guides for rolling steel rods and wires according to the invention are guides which are joined to each other and have respective inclined inner surfaces for supporting the side of the blank material to be rolled to introduce it into the gap of the grooveless rolls. A set of holders has a guide roller that surrounds the guide plate and supports the side of the blank material, and downstream of the inclined end of the inclined inner surface of the guide plate and the box-shaped guide therein. A guide roller having an assembly of guide plates, between which the gap is formed, each of the holders extending in the gap at least up to the discharge end of the gap and integrally formed with the bill; End of the blank material having a shaped holder so that it is not supported by the guide roller Prevents staggering.

The present invention will be more fully understood from the following description with reference to the accompanying drawings.

According to the invention, blank material W having a square cross section, for example, is selected from roll 101, 101 ', 102, 102'... In order to reduce the cross-sectional area in order to obtain a rolled product having the required cross-sectional shape as shown in FIG. … rolling continuously through a bath of n and n '. The roll gap between a set of rolls r and r 'is such that the reduction in material is too large or the aspect ratio B / H of the cross section of the table W sent out from the set of rolls r and r' as shown in Fig. 7 is greater than 1.5 ( Where B and H are the major axis and the minor axis perpendicular thereto), the twisting and reversal of the material occurs in the next reduction pass, as shown in FIGS. This tendency is doubled as the number of passes increases until rolling is impossible.

According to the present invention, each roll gap between a set of rolls r and r 'in the continuous pass rolling of a grooveless roll has the aspect ratio B / H of the material fed into the gaps of the rolls r and r' without the twisting and reversal of the material. It is adjusted to be smaller than 1.5 to realize stable rolling.

1.5일때 역전이 크게 증가하며 다음 로울스탠드 앞에서 비틀림이 자주 발생하므로, 재료는 다음 로울 조의 입구 측상에 서가이드와 충돌되어 불량 로울을 유발한다. 역전이 더 과도하면 단면 형상은 다음 압연에서 더욱 부정확하게 변형되어 연속 압연을 불가능하게 한다.FIG. 10 illustrates the relationship between the aspect ratio B / H and the inversion X / H × 100% when the gap in the roll bath is changed. B / H as shown in this graph

At 1.5, the reversal increases significantly and torsion occurs frequently in front of the next roll stand, so the material collides with the guiding on the inlet side of the next roll bath, causing a bad roll. If the reversal is excessive, the cross-sectional shape deforms more inaccurately in the next rolling, making continuous rolling impossible.

In contrast, when B / H <1.5, the reversal is less than 0.5% and the continuous Perth rolling is performed stably without any noticeable twist. In this respect, the aspect ratio of the rolled material immediately after passing through a set of row rods is limited to less than 1.5 according to the present invention.

And, if the aspect ratio B / H is much larger than 1.5, the cross-sectional shape of the rolled material passing through each rolling perth is determined by the double barrels 107 and 107 'which cause wrinkles 109 on the surface 108 in the next rolling as shown in FIG. Form. Conversely, if the aspect ratio B / H is less than 1.5, the cross section is in the form of a single barrel 110 which does not cause wrinkles on the surface in the next rolling as shown in FIG.

Of course, the material in which the reduction is made to a grooveless roll to have a predetermined cross section to obtain a final product of square and circular cross section rods is rolled through the box, elliptical or circular caliber of the caliber roll in a conventional manner.

13 illustrates an adopted example of a series of rolling mills to which the present invention is applied. The mill rolling mill 111 is composed of a rough rolling mill 111a, an intermediate rolling mill 111b and a finishing rolling mill 111c. The rough mill 11a has horizontal rollers 112,114 and 116 and vertical rollers 113,115 and 117. The intermediate mill 111b has horizontally 118,120 and 122 and vertically 119,121 and 123. Finishing mill 111c has horizontals 124,126 and 128 and verticals 125,127 and 129. The rolls 112 to 125 are all grooveless rolls, and four sets of rolls 126 to 129 on the downstream side are caliber rolls for obtaining a round steel rod from a square cross-section rod. For end products of square cross section, no caliber rolls are needed.

The hatched cross section 130 is the cross section of the material immediately after passing through each row of rolls, and all aspect ratios thereof are smaller than 1.5 by appropriately setting the roll clearance. Although the horizontal and vertical roll baths are alternately arranged in a series of rolling mills as in FIG. 13, the roll baths are arranged differently and the beating device is placed between the horizontal rolling mills to rotate the material to be rolled 90 ° about its axis.

In order to eliminate the drawbacks of grooveless roll rolling as mentioned earlier in the present specification, the inventors have investigated the behavior of the bars of the grooveless roll pass by many experiments, so that the stretching of the steel rod under rolling by the rodless roll is greatly influenced by the roll diameter. Found that. FIG. 14 illustrates one example of the experimental results and is limited to the ratio of the actual stretching λ to the stretching λ 'of various diameters D of the grooveless roll and a 20 × 20 mm square blank material reduced by 8 mm.

+5 값 D/H는 하기와 같이 각 대각선을 따라 용이하게 근사적으로 계산된다.The present inventors continued the experiment of grooveless rolling in order to investigate the rolling conditions for obtaining the drawing efficiency more than or equal to that in caliber rolling. As a result, it was found that high draw efficiency was achieved with a grooveless roll under the hatched rolling granular zone β of FIG. 15 illustrating the relationship between the ratio D / H of the diameter D to the roller gap H and the grooveless roll diameter D. This zone β is represented by the following formula. D / H

The +5 value D / H is easily approximated along each diagonal as follows.

60㎜ D/H

5, 60㎜>H

20㎜일때 D/H

12.5-

, 20㎜>H

10㎜일때 D/H

20-

, H<10㎜일때 D/H

35-2H.H

60 mm D / H

5, 60 mm> H

D / H at 20mm

12.5-

, 20㎜> H

D / H at 10mm

20-

, D / H when H <10mm

35-2H.

As can be seen from the value of the ratio D / H, the diameter D should be considerably smaller than the same as 360 mmβ of the grooveless or caliber rolls used therein, so that the rolling reaction force is compensated to compensate for the rigidity of the small straight grooveless rolls. It is desirable to use a supporting backup roll. However, backup rolls are easily applied to rolling mills by the experience of multiple rolling mills.

The use of grooveless rolls in zone β according to the invention is advantageous in terms of energy, since the ratio of the effective energy consumed by reducing or stretching the material cross section to the total energy for rolling is small. In this way, stable rolling by grooveless rolls is performed by effectively limiting the widening of the material according to the invention.

It was actually found in the experiment that the rolling results were greatly influenced by the absence of means for the rolled material in the gap between the caliber-free rolls. In contrast, the caliber flange prevents the rod from twisting or inverting or deforming into an inaccurate (parallel deflection) cross section, even if the guides disposed on the inlet and outlet sides only guide the rod into the caliber from a position remote from the caliber. In view of the finding, the inventors have conceived that the side guides for steel rod rolling can hold the steel rod to be rolled through the gap between the caliber rolls.

FIG. 16 is a first-stage rolling mill for rolling round bars of 75-85 mm, 90-100 mm and 110 mm outer diameters and square bars of 80 mm, 115 mm and 1453 widths, rolled from 250 mm square blue. One embodiment of the side guide for supporting the shaft portion of the rod according to the present invention applied to. In this one-stage rolling mill, the rods are fed alternately in the forward and reverse directions by rotating the rolls in the forward and reverse directions under rough rolling and intermediate rolling, and continuously feed in the forward direction under the next rolling mill.

16 illustrates a rest bar 2 (only one is shown) and a full and rear rolled guide frame 1 and 1 'for supporting a rolled guide frame. Since the rolling guide frames 1 and 1 'are substantially the same in construction, the rolling guide frames 1 are mainly described later.

The rolling guide frame 1 is a steel rod to be rolled to introduce the rods between partition plates 4 disposed on the base member 5 side by side in parallel at different intervals (e.g., gradually narrowed from left to right in the drawing). Unattempted, having a number of breakouts 4 filleted at 3 on its side, on the lower left of the figure, the upper end of which is held by parallel rail members 6, 7 and 8 welded thereto. In this embodiment, the diaphragm 4 differs in height, such as "4a" and "4b," so that the spacer 9 is melt-disposed between the diaphragm 4b and the rail member 6.

At the contact ends of the whole and rear rolling guide frames 1 and 1 'in the gaps between the roll tubs, the partition 4 is formed with an arc-shaped notch 10 concentric with each roll to avoid interference with the roll surface. Notch 10 has a radius 11 which is slightly larger than the diameter of the roll in the initial rolling stage and has a length in the direction of pressure release near its contact end. The diaphragm 4 is formed along a notch with concentric chamfers 12 therein, except for three diaphragms, all on the guide frame 1, especially on the right side of the figure, for introducing the rolled material leaving between the rolls.

It is required that three distances B ₁ ′, B ₂ ′ and B ₃ ′ be greater than three distances B ₁ , B ₂ and B ₃ between the diaphragms so as to widen the rolled material in one-way continuous rolling.

As shown, the plates 4a and 4b arranged on the left side of the third plate from the rightmost plate of the drawing define plates 4a and 4b on the front and rear guide frames defining a rolling zone therebetween for rough rolling and intermediate rolling. It is connected at its contact end by fitting vertical ridges 14 and vertical grooves 13 formed therein to resist the lateral pressure transmitted from this rolled sheet.

The outermost plates 41 'and 4b' have projections 15 extending in the axial direction of the roll for connecting the front and rear plates 4a 'and 4b' at their contact positions by connecting members 16 coupled to the projections 15 with bolts 17. do.

This connection of the front and rear plates is carried out under the condition that the respective guide frames 1 and 1 'contact each other so that the base member 5 is supported on the rest bar 2 to surround the roll bath. The base member 5 is clamped at any position in the axial direction of the roll by a limiting plate 18 coupled to the rest bar 2 with bolts 19 to secure the side frame to any adjusted position. The base guide is arranged between the diaphragms 4b as shown.

In one example of rolling, a 250 mm wide blueham is rolled alternately in the forward and reverse directions through six passes of the defined rough rolling zone a and three passes of the defined rough rolling zone b, and also to obtain a billet of 170 mm wide. Rolling through two passes of alternating forward and reverse of the defined intermediate rolling zone d and through one pass of the defined intermediate rolling zone d. The billet is then gradually rolled forward in the next quality rolling zones e, f and g in order to obtain a 150 mm wide billet and subsequently passed through a tandem finishing mill to obtain the desired billet.

The roll has a barrel length of 1,000 mm and an initial outer diameter of 650 m, which is reduced to a minimum diameter of 410 mm by repeating the barrel to modify the barrel surface during use. When river rolls with the same original diameter are used, they are discarded at a barrel outer diameter of 570 mm. The side guide according to the present invention reduces the number of wools by uniform wear and retrieval of the rolls, thereby effectively using the rolls up to the minimum diameter, thereby reducing the original unit cost of the rolls by one tenth of the conventional ones. .

The limited rolling zones for rough and intermediate rolling have a width of the inlet and outlet shaft portions that are preferably at least 10 mm larger than the material width and the limited rolling zones for finishing rolling have an outlet side about 20 mm larger than the material width and an inlet side about 10 mm larger. . In this case, the width of the material is widened by a reduction of about 30%, and for caliber rolls the value is about 20%.

And, in the Caliber roll pass, the inlet guide is used to precisely introduce the material to be rolled into the roll gap in the same way as in the Caliber roll pass. As in the example shown in FIGS. 17 (a) and 17 (b), the material W to be rolled is fed into the gap of the caliber rollers 204 and 204 'for rolling, and the material is guide rollers 203 and 203. It is held in position by 'and guided by guide plates 202 and 202' of the inlet guide 201. In this case, as long as the material W is held by the guide rollers 203 and 203 'as shown in Fig. 17 (a), no reversal of the material W occurs. As soon as the trailing end of the material leaves the guide rollers 203 and 203 'as shown in Fig. 17 (b), the material loses its holding means, so the material reverses to change the cross section of the trailing end C to a parallelogram cross section as shown in Fig. 18. Cause. As the flatness ratio Bo / Ho and convex b / Ho of the material becomes large, the reversal becomes severe, making the scheduled rolling process impossible.

As shown in FIG. 19 illustrating an example of the rear end portion of the product under the molding pass, 휜 e to be removed in a separate process occurs on the rear end portion. If this 휜 e becomes excessive, 휜 is rolled in a small gap, not a caliber, causing an unusually large rolling load to stop and damage the mill. If the reversal is excessive, the cross-sectional size becomes larger than the predetermined value, so that the material cannot pass through the inlet and outlet guides in the roll, causing the rolling mill to stop and the guide to break.

In order to avoid this drawback inherent in caliber rolls, an inlet guide for calibers is proposed in accordance with the present invention, which supports the material to be rolled until it leaves the grooveless roll gap to mitigate the reversal that otherwise occurs on the back end of the material. And prevents the improved productivity due to the high drawing efficiency from being lowered due to the reduction in the production resulting from the removal of the grip on the rear end of the rolled material.

21 and 22 illustrate the basic structure of the inlet guide. As shown, between the guide plates 202 and 202 ', the guide rollers 203 and 203', the guide rollers 203 and 203 'and the grooveless rollers 204 and 204' as shown in the prior art of FIGS. 17 (a) and 17 (b). And beak-shaped holders 205 and 205 'which extend over the exit δ where the deformation of the material is complete so as to surround and support the material in the axial direction of the roll through the gap between grooveless rolls 204 and 204'. Although a set of guide rollers 203 and 203 'is shown, a coarse stand operating at significantly lower rolling speeds is provided with two sets of guide rollers to enhance the material's honing and in addition to a guide roller at the outlet side.

The material W to be rolled is naturally deformed to extend in the axial direction of the roll by grooveless roll rolling. In other words, the deformation of the material W is advanced to the axial sorting of the roll to widen its width from the beginning to the end of rolling. The shape of the deformation can be roughly expected. Thus, the beak shaped holders 205 and 205 'have inner reel relief surfaces 206 and 206' corresponding to the transition of deformation of the material in the axial direction of the grooveless roll. The relief surfaces 206 and 206 'are set to obtain the optimum gap K between the sheet to be rolled and the surface. If the gap K is smaller than 1 mm, the side of the material to be rolled is in contact with the relief surfaces 206 and 206 'to cause scratches on the material surface. On the other hand, when the gap K is 5 mm or more, the holders 205 and 205 'do not restrain the material and thus do not prevent the reversal of the material. Therefore, the gap K is preferably 1 to 5 mm in order to prevent reversal over the length of the material in order to stabilize rolling into the grooveless roll.

Beak-shaped holders 205 and 205 'also guide the front end of material W into the roll gap. When the material is guided by guide rolls 203 and 203 'without beak shaped holders, the front end of the rolled material W sent out from the roll gap is twisted about its axis, which prevents the material from being introduced into the next roll stand. do. This rolling problem can be eliminated by the beak shaped holder.

Figures 24 (a) and 24 (b) show the plane and side view of the specific structure of the inlet guide 201 according to the invention, which is applied to the horizontal grooveless rolls 204 and 204 'showing the main part of the cross section. FIG. 25 is a perspective view showing the outer profile of the inlet guide 201, and FIG. 26 is a developed perspective view. The inlet guide 201 has guide plates 202 and 202 'which are coupled to each other and have respective inner shaft inclined surfaces, and a set of holders 207 and 207' surround the guide plates 202 and 202 'and the front ends of the inclined surfaces of the guide plates 202 and 202'. Including guide rollers 203 and 203 'supporting the sides of the material W adjacent to the box, the box-shaped guide 208 contains an assembly of guide plates 202 and 202' and rollers 207 and 207 'therein and guide rollers 203 and 203'. To be fixed. The holders 207 and 207 'are held by the holding bolts 209 passing through the side edges of the box-shaped guide 208 and screwed into the screw holes 209' formed in the holder. The adjustment screw 210 is inserted in the sidewall of the box-shaped guide 208 to set the distance between the holders 207 and 207 'to be adjustable. The adjusting screw 211 is inserted into the holders 207 and 207 'and, with its help, makes contact with the reaction plate 212, and the adjusting screw 211 sets the gap between the guide rollers 203 and 203'. Set screws 213 and 214 are inserted into the upper wall of the box-shaped guide 208 to fix the guide plates 202 and 202 'and the holders 207 and 207'. The guide roller is supported on pin 215 rotatably through bearing 216. In this embodiment, beak shaped holders 207 and 207 ', although beak shaped holders 205 and 205', which are shown integrally with holders 207 and 207 'at their ends, extend into gaps of grooveless holes 204 and 204' to the exit. Is formed separately from or fixed to the holders 207 and 207 'by welding or seton screws.

A 150 mm square blank was rolled by a grooveless roll through 12 passes with the inlet guide and then by a caliber roll through 6 passes to obtain a 16 mm diameter round steel bar. On the other hand, the same material is rolled equally by using a conventional inlet guide having guide rollers 203 and 203 'but not having separate shape holders 205 and 205'. Compared with the inversion of the rear end of the rolled material, when the clearance K between the relief surfaces 206 and 206 'of the beak-shaped holders 205 and 205' and the material is 3 to 5 mm, the inversion angle at the rear end of the material is 27 ( As shown in a), the inlet guide shall be within 5 ° and its angle shall not leave the next caliber rolling and one-third of the test rod shall not pass through the inlet guide of the next mill and the remaining two-thirds may be rolled to a 16 mm diameter. Significant reversal occurs at the rear end of the material, and the length of the fin formed on the rear end is more than five times that according to the present invention, which significantly lowers the production rate as shown in FIG.

The inlet guide according to the invention is also applied to rolling steel rods and wires of small diameter into grooveless rolls, where the inlet guide is important for improving the production rate.

Six horizontal, four sets of four top rolling mills 217, 218, 219, and 220 alternately arranged, i.e. with four upstream passes, and two sets of two top rolling mills 221 and 222 for two downstream passes. And a continuous finishing randem rolling mill device composed of a vertical rolling mill. An 18 mm square blank was gradually rolled according to the pass schedule shown in FIG. 29 to produce an 11 mm diameter round steel bar.

In contrast, although conventional 18 mm square blanks can be rolled into 11 mm round rods through six passes of alternating ellipse and circumferential calibers, all conventional caliber rollings face the aforementioned drawbacks. On the other hand, when an 18 mm square blank rod uses two top rolling mills including grooveless rolls according to a conventional method and the remaining two upstream passes are rolled into 11 mm round steel rods through four upstream passes by a caliber roll, Rods rolled through the rolls become excessively flat to destabilize the rolling.

This results from the fact that the roll diameters of the two top rolling mills are quite large, such as 360 mm, so that the ratio D / H is also large, which significantly lowers the drawing efficiency, that is, the width of the material is too wide. The table indicates the significant difference in stretching efficiency between the prior art pass schedule of FIG. 32 and that according to the invention of FIG.

[table]

According to the present invention, as described above, the diameter of the grooveless rolls can be reduced to 100 mm with the aid of a backup roll, so the ratio D / H is considerably smaller than that in conventional grooveless rolling to increase drawing efficiency or Likewise, stable rolling is achieved by preventing the width of the rolled material from becoming wider.

Although the application of the method according to the invention to a continuous finishing mill in the process of producing circular steel rods of 11 mm diameter is described, the present invention will reduce the cross-sectional area of the rods, rather than the forming pass, to give the final cross-sectional shape of the product. It can also be advantageously applied to upstream passes with the purpose. In addition, the present invention is applied not only to a continuous rolling mill but also to a single rolling mill such as a reverse rolling mill. Although four top rolling mills have been described, backup means are not essential to the invention.

As can be seen from the foregoing, the present invention is useful for rolling steel bars and wires stably and effectively with grooveless rollers at high drawing efficiency, thereby significantly improving productivity. The side guide according to the present invention achieves grooveless rolling without twisting and reversing steel bars, thereby broadening the field of grooveless rolling with the following effects. The roll does not have a caliber, so it is easy and inexpensive. As the surface of the roll used for rolling becomes wider, rolling per wool increases. Since the same rolls can be used to roll products in a wide range of sizes, the number of rolls to be repaired is smaller than in the prior art. Since no caliber is formed in the roll, the original outer diameter of the roll is smaller than that of the caliber roll, so that the mill body, housing, motor and attachment are compact. They can be used with smaller diameters, so the life of the roll is long and there is no risk of breakage because of the grooveless roll. The roll does not need to be changed each time the size of the rolled material is changed.

Therefore, the rest time is reduced. Downtime for adjusting the centers of the rolls and guides for repairing by grinding broken or partially corroded calibers due to melting or combustion to adjust the centers of the upper and lower roll flanges during rolling can be avoided. The production rate is quantified from the reduction of product binding such as meat tail. In addition, the inlet guide to be used directly for grooveless roll rolling can effectively prevent the problems inherent in grooveless roll rolling by casting the material at the outlet of the roll gap, so that the rolling energy can be effectively utilized and the production rate is significantly improved. do.

While the invention has been described and illustrated with reference to the embodiments employed, it will be understood by those skilled in the art that other forms or details may be changed therein without departing from the scope and spirit of the invention.

Claims (13)

Side guides are provided between the rolling mills to support the rectangular cross-section blank material and guide it toward the gap between the grooveless roll irradiator, and an inlet guide for introducing the rectangular cross-section blank material into the gap is provided for each rolling mill. A method of manufacturing steel bars and wires by passing the rectangular cross-section blank material through a plurality of sets of grooveless rolls forming a series of continuous rolling mills, the cross section of the blank material passing through the gap between the grooveless rolls of each group. A steel bar and wire manufacturing method for setting the gap so that the ratio of the large intestine side to the short side is less than 1.5. The method of claim 1, wherein the ratio of the diameter D to the gap H is equal to D / H.

A method for manufacturing steel rods and wires which increases the deformation of the blank material in the rolling direction by making it significantly smaller to satisfy the relationship of +5. According to claim 2, wherein the diameter of the grooveless roll of each set, H

D / H at 60 mm

5, 600 mm> H20 mm

D / H

12.5-

, 20㎜> H

D / H at 100 mm

20-

, D / H when H <10mm

Steel bar and wire manufacturing method that satisfies 35-2H relationship. 4. A method as claimed in claim 2 or 3, wherein at least a portion of the continuous rolling mill comprises a backup roll for supporting a rolling reaction. 2. The rollers of claim 1 wherein each of the rolling mills comprises the same set of rolling rolls and is brought into contact with each other in the gaps between the rolls so as to surround the rolls on all and the rear thereof to form a defined rolling zone side by side in the axial direction of the rolls. Combined all and the rear rolling guide frame is configured in the side guide of the angular rolling mill, the steel bar and the wire manufacturing method of each said rolling zone divided by the side guide tank constitutes a rolling mill. 6. The method of claim 5, wherein the contact ends of the front and rear rolling guide frames are connected to each other in the lateral outer side guides. The method of claim 5, wherein the contact ends of the front and rear rolling guide frames are connected to each other to support the axial pressure on the guide frame during rolling. 6. The method of claim 5, wherein the defined rolling zones have different widths. 9. The method of claim 8, wherein each rough rolling zone has a uniform overall and posterior width, wherein the remaining portion of the defined rolling zone is lower than the rough rolling zone, and a portion of the remaining portion of the defined rolling zone is all. Steel rod and wire manufacturing method with wider back width. 6. The method of claim 5 wherein the side guides are axially adjustable in the roll. The guide plate of claim 1, wherein the inlet guides of the rolling mills are joined to each other and have respective inner inclined surfaces for supporting the side surfaces of the blank material introduced into the gap between the grooveless rolls of the rolling mill, A set of holders having a guide roller supporting the side surface of the inclined end portion of the inclined end of the inner inclined surface, and a box-shaped guide in which the guide plate, the holder of the set and the guide roller are adjustable to be assembled. And, each of the holders includes a beak-shaped protrusion extending into the gap to prevent the blank material from twisting. 12. The steel bar and wire according to claim 11, wherein each of the beak-shaped protrusions includes an inner relief surface that substantially faces expansion of the blank material and faces the blank as the blank material continues to shrink through the gap between the rolls. Manufacturing method. The steel bar and wire manufacturing method according to claim 12, wherein the inner relief surface of the bent-shaped protrusion forms a gap of 1 to 5 mm with a blank material.

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