JP2641834B2 - Tilt rolling machine for seamless steel pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inclined rolling device for seamless steel pipes using inclined rolls.

[0002]

2. Description of the Related Art As shown in FIG. 4, a Mannesmann type punch has a pair of barrel type rolls 1a and 1b. The pair of rolls 1a and 1b are given a surface angle of several degrees,
It is arranged at an angle to the pass line. The heated billet 3 moves forward while being rotated by the rolls 1a and 1b, and a hole is easily made in the center thereof due to the rotational forging effect received during the rotation, and is drilled by the tip of the plug bar 5. In such a conventional perforator, 9% C
When high alloy steel such as r steel and 13% Cr steel is continuously drilled, the slip between the roll and the material to be rolled 4 increases, and the material to be rolled 4
, A hole is formed in the center of the material to be rolled 4 by rotary forging before being pierced at the tip of the plug bar 5, and the hole is apt to remain as an inner surface flaw after piercing.

As a countermeasure for preventing such a problem, there is a technique for imparting a concave shape to the surface of the roll by knurling or knurling at the time of reshaping the roll, as disclosed in Japanese Patent Application Laid-Open No. 2-251305. In addition, Japanese Unexamined Patent Publication No.
As shown in JP-77708-A, there is a technique of performing these processes online during rolling to impart a concave shape to the roll surface. The concave shape of the roll surface imparted by these techniques is suitable for the purpose of improving the biting property of the material to be rolled into the roll, but is intended to improve the advance speed of the material to be rolled after the biting. To achieve this, the required depth of the concave shape is too deep, leaving a trace on the surface of the material to be rolled after rolling, which is a problem. In addition, the apparatus which gives a concave shape to the roll surface online has a drawback that it is too large to be installed in an inclined rolling mill, and is difficult to put into practical use.

[0004] In addition, as disclosed in Japanese Patent Application Laid-Open No. 61-180603, a technique for specifying the opening amount of a roll within a certain range with respect to the entrance diameter of a material to be rolled, As disclosed in Japanese Patent No. 49308, there is a technique of rolling by changing not only the roll opening amount but also a plug lead amount, a roll inclination angle, a roll crossing angle, and the like. However, when these rolling conditions are changed, there is a problem that predetermined dimensions cannot be given to the material to be rolled by rolling.

[0005] The inventors of the present invention have proposed a metal, metal carbide, metal nitride, metal carbonitride, metal oxide and metal oxide for the purpose of reducing the slip between the material to be rolled and the roll. A rolling technique using a lubricant in which one or a mixture of silicon compound powders or a mixture thereof and a polymer are dispersed in water was proposed. In this case, as shown in FIG. 5, a spray nozzle 8a in which the lubricant is attached to a roll case 9a (or 9b) of a Mannesmann perforator.
(Or 8b) was sprayed and supplied toward the surface of the roll 1a (or 1b). However, in this method, the pipe for supplying the lubricant must be removed every time the roll is replaced, which consumes working time. Further, there is a problem that the lubricant remaining in the lubricant supply pipe 12 in the roll case may be solidified before the next use, causing clogging of the pipe, and it takes much time for flushing and the like.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is intended to reduce the slip between the roll and the roll without impairing the surface properties of the outer surface of the roll and without changing the setting of the rolling conditions. An object of the present invention is to provide an apparatus capable of reliably injecting and supplying a lubricant to a roll surface of a Mannesmann perforator, for the purpose of reducing the occurrence of internal flaws.
The present invention provides an apparatus that does not require removal of piping even when changing rolls.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an apparatus for rolling while supplying a lubricant exhibiting a lubricating effect between a material to be rolled and a roll surface. A tilting rolling device for a seamless steel pipe, wherein a spray nozzle for jetting and supplying is provided at a tip of a billet entry side guide.

[0008]

The present invention will be described below in detail with reference to the drawings.
FIG. 1 is a view showing a rolling apparatus according to the present invention. The entrance guide 6 for guiding the cylindrical billet 3 to the pass line of the rolling rolls 1a and 1b is called a canon because of its cylindrical shape. The cannon 6 has various sizes according to the diameter of the billet 3. Spray headers 7a and 7b are installed at the tip of the cannon 6, and a spray nozzle 8
The lubricant is sprayed and supplied from a and 8b to the surfaces of the rolls 1a and 1b.

FIG. 2 shows a spray header 7 used in the present invention.
a and 7b will be described in detail. A mechanism for adjusting the positions of the spray headers 7a and 7b according to the diameter of the billet 3 is required. In the example of FIG. 2, a mechanism for adjusting the positions of the spray headers 7 a and 7 b in a direction orthogonal to the shoe interval using the hydraulic cylinder 10 and adjusting the positions of the spray headers 7 a and 7 b in the rolling direction using the hydraulic cylinder 11. And a mechanism to perform. Of course, other adjustment mechanisms may be applied.

FIG. 3A is a diagram showing the positional relationship between the rolls 1a and 1b, the roll cases 9a and 9b, the billet 3, and the guide shoes 2a and 2b when rolling a large-diameter billet. () Is a diagram showing the positional relationship between small-diameter billets 3 when they are rolled. By adjusting the positions of the spray headers 7a and 7b for supplying the lubricant to the positions as shown in FIG. 1 at the tip of the cannon 6, not only the difference in billet diameter but also the setting change of the roll interval and the guide shoe interval are affected. Instead, it is possible to spray and supply the lubricant to the roll surface.

Further, regardless of the roll replacement, the guide shoe replacement and the cannon replacement, the lubricant supply pipe 12 can be permanently installed, so that the spray headers 7a and 7b and the spray nozzles are provided in the roll cases 9a and 9b shown in FIG. 8a, 8b
In contrast to the case where the was installed, the problem of clogging of the lubricant in the piping was solved. The present invention is applicable to the case where the rotary disc guide shoes 2a and 2b shown in FIG.
As shown in FIG.
3b, roller type guide shoe 1 as shown in FIG. 6 (b)
4a and 14b can also be applied, and the same effect can be obtained.

[0012]

EXAMPLES The present invention was applied to a rolling roll cycle of 5000 billets 3 having a diameter of 110 mm or more and 175 mm or less. The material of the rolled billet 3 is 1500 for high alloy steel with a Cr content of 1 wt% or more in each roll cycle.
In the book, the rest is all carbon steel. The lubricant used was 10 wt% silicon carbide having an average particle size of 150 μm dispersed in water together with 1 wt% of a cross-linked acrylic resin, and a standard amount of 10 kgw / min-roll was sprayed under the standard conditions to enter each roll. Mouth fed. For comparison, rolling was also performed on a rolling device without using a lubricant.

Table 1 shows the effect of the application of the rolling according to the present invention on the piercing efficiency η during carbon steel rolling and high alloy steel rolling. Here, the perforation efficiency η is a component VR-X of the circumferential speed of the inclined roll in the forward direction of the rolled material and the forward speed VM of the rolled material.
Using −X, it can be determined that the smaller the piercing efficiency η, the greater the slip between the material to be rolled and the roll, with a value defined as in the following equation (1).

Η = {(VM−X) / (VR−X)} × 100 (1) Compared with the average value of the piercing efficiency η during normal rolling without supplying a lubricant, the apparatus of the present invention was The average value of the piercing efficiency η in the rolling used was about 3% in carbon steel rolling and 27% in high alloy steel rolling.
% Improved. As can be seen from Table 1, by applying the present invention, similarly to the improvement of the drilling efficiency η, a rolling error called a so-called sticker such as a failure of the billet to bite or a failure of the bottom end of the raw tube is reduced.

[0015] Table 1 also shows the effect of the application of the rolling according to the present invention on the occurrence of internal flaws during the rolling of high alloy steel. Internal surface flaws generated by about 1.3% during conventional rolling were reduced to about 0.1% when rolling was performed using the apparatus of the present invention while supplying a lubricant. It has been concluded that the internal flaws generated during the practice of the present invention are also caused by the central defect of the billet material, and the use of the apparatus of the present invention substantially eliminated the internal flaw.

Table 2 shows a comparison of the time required for the roll change between the lubricant supply device of the present invention and the conventional lubricant supply device. In the conventional apparatus, at the beginning of the roll changing operation, the lubricant in the pipe incorporated in the roll case is flushed, and then separated from the fixed pipe on the piercer machine side. Furthermore, at the end of the roll change operation, the connection of the pipe and the filling of the lubricant must be performed. In the apparatus of the present invention, these work times are unnecessary, and the roll replacement work time is reduced by about 10 minutes. This is a time reduction of about 13% of the entire roll changing operation, and greatly contributes to improvement in productivity.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

According to the present invention, it is possible to improve the productivity of the seamless steel pipe and prevent the surface properties of the inner surface of the product pipe from deteriorating.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a lubricant supply and rolling device according to the present invention.

FIG. 2 is an operation explanatory view of the spray header of the embodiment.

FIG. 3 is an application example of a lubricant supply and rolling device according to the present invention.

FIG. 4 is a perspective view showing an outline of rolling of the inclined drilling machine.

FIG. 5 is a schematic view of a conventional lubricant supply and rolling device.

FIG. 6 is a perspective view showing an example of a guide shoe.

[Explanation of symbols]

1a, 1b Roll 2a, 2b Guide shoe 3 Billet 4 Rolled material 5 Plug bar 6 Entry guide (cannon) 7a, 7b Spray header 8a, 8b Spray nozzle 9a, 9b Roll case 10, 11 Hydraulic cylinder 12 Lubricant supply Piping 13a, 13b
Fixed type guide shoe 14a, 14b Roller type guide shoe

Continuation of the front page (72) Inventor Yuki Uesaka 1-1-1 Kawasaki-cho, Handa-shi Kawasaki Steel Corporation Chita Works (56) References JP-A-5-57307 (JP, A)

Claims (1)

(57) [Claims] 1. An inclined drilling machine for piercing and rolling a material to be rolled, wherein a spray nozzle for spraying a lubricant between the material to be rolled and the surface of the roll onto the surface of the roll is provided at a tip end of a billet entry side guide. An inclined rolling device for seamless steel pipes.