JPH08112767A - Steel piece maintenance cleaning grinding wheel and steel piece maintenance cleaning grinding method - Google Patents

Abstract

PURPOSE: To provide a steel piece maintenance cleaning grinding wheel capable of realizing improving grinding efficiency by eliminating necessity for increasing grinding power and for enlarging a thickness of the grinding wheel with small rotary drive force and without worsening grinding performance (sharpness). CONSTITUTION: In grading (gage) of an abrasive standardized in JIS R6001, in the case of forming a shape with an external diameter 400mm or more further with thickness 10mm or more less than 50mm, and in the case of forming a shape with thickness 15mm or more 45mm or less, further in the case of forming a shape with thickness 20mm or more 40mm or less, a grinding wheel has a grinding work part 1c using an abrasive of mixing 10 to 40wt.% fine grain abrasive of two-grading (gage) separated different kind or the same kind. The grinding wheel has a fine grain reinforced part 1b around a hole part 1a, to mix a 2.5 to 20wt.% cut glass fiber reinforcing material in the fine grain reinforced part 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grindstone for servicing steel pieces and a grinding method for servicing steel pieces, which are used for removing flaws in steel pieces.

[0002]

2. Description of the Related Art The surface of a slab after slabging may have surface defects such as surface defects due to the steel ingot itself or surface defects due to heating or rolling during sizing. Therefore, when such surface flaws are harmful, it is necessary to take care of the steel pieces to remove the surface flaws.

For the maintenance of such steel slabs, a maintenance device such as a grinder, a scarfer, and a peeling machine is used. The rolling ratio, the permissible standard of the surface flaw, the depth of the surface flaw, the permissible depth of the maintenance, and the maintenance. The care device is selected and used depending on the surface unevenness limit and the like.

Among them, the swing grinder includes a swing grinder, a self-propelled grinder, a stationary grinder, and the like. When the grinder removes a steel piece,
Conventionally, the outer diameter is 455 mm from the viewpoint of emphasizing grinding efficiency.
Grindstones of ~ 760 mm and thickness of 50 mm-75 mm have been employed.

When performing grinding with such a grindstone, in order to further improve the grinding efficiency, it is necessary to enlarge the grinding motor and further increase the grinding pressure. Increased grinding pressure (200-
1000 kgf) Heavy grinding wheels have been used.

And, in order to perform grinding with a high grinding pressure,
It has been dealt with by increasing the thickness of the grindstone to 65 mm or more, and mixing a reinforcing material in order to further secure safety.

[0007]

As described above, in order to improve the grinding efficiency by speeding up the flaw removal of the steel slab and also by grinding and removing a large amount, (1) increase of grinding wheel grinding pressure (2) ) While methods such as increasing the thickness (width) of the grindstone have been adopted, increasing the grinding wheel grinding pressure by the method of (1) requires increasing the required rotary drive force capacity and improving the strength of the grindstone. Therefore, if the grindstone thickness (width) is increased by the method (2), it is necessary to increase the capacity of the power system and the strength of the entire grinder structure in order to maintain the required grinding pressure and rotation speed. In addition, an increase in the grinding thickness (width) due to an increase in the thickness of the grindstone causes the generation or increase in the generation of grinding heat and a reduction in the radiation capacity, so that a very large effect cannot be expected and the yield also decreases, Improvement of grinding efficiency There is a problem in that it is not easy, it has been a problem to solve such problems.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and it is possible to increase the mixing amount of the reinforcing material without increasing the grinding pressure and the grindstone thickness. An object of the present invention is to provide a grindstone for servicing a steel piece and a grinding method for servicing a steel piece capable of improving the grinding efficiency without increasing the grinding performance (sharpness) with a small rotational driving force without increasing the grinding power. I am trying.

[0009]

SUMMARY OF THE INVENTION A steel piece maintenance grindstone according to the present invention has an outer diameter of 400 mm or more and a thickness of 10 m.
In the embodiment of the steel piece maintenance grindstone according to the present invention, the outer diameter is 400 mm or more and the thickness is 15 mm or more.
The shape may be mm or more and 45 mm or less, or the shape may have an outer diameter of 400 mm or more and a thickness of 20 mm or more and 40 mm or less.

Further, in the embodiment of the whetstone for caring for a steel piece according to the present invention, in the abrasive grain size (count) defined in JIS R6001, two fine grain abrasives separated by two grain sizes (count) are used. Approximately 40% by weight mixed abrasives are used, or 10-40% by weight of the same type of fine-grained abrasives separated by 2 grains (count) from the grain size (count) defined in JIS R6001. It is also possible to use the above-mentioned abrasive.

Furthermore, in the embodiment of the steel slab care grindstone according to the present invention, a fine grain reinforcing portion is provided around the hole of the grindstone, and the fine grain reinforcing portion is provided with a chopped glass fiber reinforcing material. It may have a fine-grained reinforcing portion mixed with 5 to 20% by weight.

Further, the method for grinding a steel piece for maintenance according to the present invention uses the above-mentioned grinding stone for caring for a steel piece to perform rough grinding of a steel piece, and also a grinding for maintenance for a steel piece according to the present invention. The method uses the above-mentioned steel piece care grindstone, and the direction of the side surface of the grindstone is 90 ° with respect to the grinding direction of the steel piece.
The feature is that grinding is performed in a state of being inclined at an angle less than.

FIG. 1 shows an embodiment of a grindstone for servicing steel pieces according to the present invention. The grindstone 1 for servicing steel pieces has a hole 1a at the center and the hole 1a. 1
There is a fine grain reinforcing portion 1b around a, and this fine grain reinforcing portion 1b
Is reinforced by mixing the cut glass fiber reinforcing material in an amount of 5 to 40% by weight.
A grinding portion 1c is provided on the outer side of b, and the grinding outer peripheral surface 1d is used to grind a steel piece.

The grindstone 1 for caring for steel pieces according to the present invention has an outer diameter D of 400 mm or more and a thickness T of 10 mm.
The shape is not less than 50 mm.

In this case, the outer diameter D is set to be 400 mm or more because when the outer diameter D is less than 400 mm, the flaw portion of the steel piece is ground to a depth more than necessary and the grindstone is used. This is because the replacement frequency increases and the workability for removing flaws on the surface of the steel slab deteriorates. The above-mentioned problems are solved by forming the outer diameter D into a shape of 400 mm or more.

In order to carry out the flaw removal work of the steel slab, it is necessary to secure the strength of the grindstone, and a thickness T of at least 10 mm is required, preferably 15 mm or more, more preferably 20 mm or more. I am trying.

On the other hand, if the thickness T of the grindstone becomes large, it becomes possible to grind and remove the flaws of the steel slab more quickly, but if the thickness T of the grindstone becomes too large, the required grinding pressure will be increased. Since it is necessary to increase the capacity of the rotary power system required to maintain the rotation speed or to increase the strength of the grinder structure, the thickness T of the grindstone 1 should be less than 50 mm. It is supposed to be eggplant. If the thickness T of the grindstone 1 becomes smaller, the rotational driving force can be made smaller, and the generation of grinding heat can be suppressed to further prevent the deterioration of the grinding performance. Therefore, the thickness T is more preferably 45 mm.
Hereafter, it is more preferably 40 mm or less.

Therefore, in the steel piece maintenance grindstone 1 according to the present invention, the outer diameter D is 400 mm or more and the thickness T is 1.
0 mm or more and less than 50 mm, more preferably the thickness T is 15
mm or more and 45 mm or less, more preferably the thickness T is 20
It has a shape of not less than mm and not more than 40 mm.

Further, in the grindstone 1 for caring for the steel piece according to the present invention, Table 1 shows the construction of the grinding portion 1c.
To the particle size of the abrasive material defined in JIS R 6001 shown in Table 4 (particle size # 8 to # 220;
In No. 0), it is desirable to use an abrasive in which 10 to 40% by weight of fine-grained abrasives separated by two grain sizes (count) are mixed.

In some cases, as a structure of the grinding portion 1c, JIS R 600 shown in Tables 1 to 4 is used.
In the abrasive grain size (count) established in 1, it is possible to use an abrasive in which 10 to 40% by weight or more of fine grain abrasives of the same kind separated by two grain sizes (count) are mixed.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

In this case, the JIS shown in Tables 1 to 4
In the abrasive grain size (count) defined in R 6001, an abrasive mixture of 10 to 40% by weight of different or similar fine grain abrasives separated by 2 grain sizes (count) is used for the grinding portion 1c of the grindstone 1. By doing so, it is possible to further improve the grinding efficiency.
By adopting the constitution of c, when abrasives of a single grain size are used, or when abrasives of adjacent grain sizes (that is, one grain size (count) apart) are mixed and used, Even if mixed abrasives having different particle sizes (counters) are used, or even if finely divided abrasive particles having two particle sizes (counts) are mixed and used, less than 10% by weight of fine abrasives or 40 It becomes possible to further improve the grinding efficiency as compared with the case where the mixture is used in excess of wt%.

FIG. 2 shows an embodiment of a grinding method for caring for a steel piece according to the present invention, in which a steel piece 2 is flawed by using the grinding stone 1 for caring for a steel piece as described above. The case where grinding is performed with the side surface (direction) of the grindstone 1 tilted with respect to the grinding direction G of the piece 2 by an angle θ shown in FIG.

By adopting such a grinding method,
Both ends of the ground portion have rounded shapes (R) as shown in FIG. On the other hand, when performing grinding with the grinding direction G of the steel slab 2 and the side surface (direction) of the grindstone 1 being parallel to each other, both ends of the ground portion are formed as stepped portions having standing walls. Therefore, when the steel slab is rolled after this, the standing wall of the stepped portion falls down, so that the surface of the rolled material after rolling is in a state where streaks are formed. On the other hand, by grinding the side surface (direction) of the grindstone 1 with the angle θ as described above, both ends of the ground portion have a rounded shape (R). Even when the steel strip is rolled, no streaks are formed on the surface of the rolled material.

Further, as described above, by grinding the side surface (direction) of the grindstone 1 inclining by the angle θ, the grinding powder is scattered in a direction inclined with respect to the grinding direction of the steel slab 2. As a result, the steel pieces 2 do not scatter in the grinding direction, so that it is possible to prevent the grindstone 1 from being clogged.

[0029]

The grinding stone for caring for steel pieces according to the present invention has an outer diameter of 400 mm or more and a thickness of 10 mm or more and 50 mm.
Since it has a shape of less than, it improves the grinding efficiency when scratching a steel slab without increasing the grinding pressure, with a small rotational driving force, and without deteriorating the grinding ability (sharpness). Will be brought.

In some cases, the outer diameter is 400 m.
m and a thickness of 15 mm or more and 45 mm or less, and an outer diameter of 400 mm or more and a thickness of 20 mm or more and 40 mm or less. The capacity is further reduced, and the generation of grinding heat is further suppressed.

Further, in the grindstone for servicing steel according to the present invention, in the abrasive grain size (count) defined in JIS R 6001, different or same fine grain abrasives separated by two grain sizes (count) are used. By using a composition in which 10 to 40% by weight of the abrasive is mixed, the grinding efficiency is further improved.

Furthermore, in the grindstone for servicing steel according to the present invention, a fine grain reinforcing portion is provided around the hole portion of the grindstone, and the fine grain reinforcing portion has a cut glass fiber reinforcing material in an amount of 2.5 to 20 weight. %, The strength of the grindstone itself is further increased by having the fine grain reinforced portion. In this case, as the abrasive used for the fine grain reinforcing portion, # 36-
More preferably about # 100.

Further, in the grinding method for caring for a steel piece according to the present invention, the grinding stone for caring for a steel piece is used to roughly grind a steel piece so that the grinding pressure is not increased and a small rotary drive is performed. With the force, and also without deteriorating the grinding ability (sharpness), the flaws of the steel piece can be efficiently and favorably removed.

In the grinding method for caring for billet according to the present invention, the grindstone for caring for billet is used, and the side surface of the grindstone is inclined at an angle of less than 90 ° with respect to the grinding direction of the billet. By performing grinding, the steel slab is satisfactorily removed without any residual blemishes, and when rolling is performed after slaw removal, rounded parts are formed at both ends of the ground part. However, since the stepped vertical wall is not formed, it is possible to prevent the generation of streaks in this part after rolling, and the grinding powder is inclined with respect to the grinding direction of the billet. Since the particles are scattered and discharged in a certain direction, the occurrence of clogging of the grindstone is also prevented.

[0035]

EXAMPLES Examples of the present invention will be further described below.

Example 1 A case will be described in which the surface of a steel slab 2 made of chromium / molybdenum steel was subjected to surface flaw removal grinding in the manner shown in FIG. 2, using the steel slab care grindstone 1 shown in FIG.

In this embodiment, Showa Denko Co., Ltd. was used as the abrasive (abrasive grains) that constitutes the grinding portion 1c of the grindstone 1.
Stermorundum SR (made by sintering # 10 to # 24 alumina) was used.

The grain size (count) of the abrasive (abrasive grains) used here is # 8 to # 2 shown in Tables 1 and 2.
As shown on the horizontal axis of FIG.
2, # 14, # 16, and # 20 were each 100% by weight, and # 14 was 70% by weight, and 30% by weight of # 16 fine-grained abrasive separated by 1 grain size (count) from this. And a mixture of 30% by weight of # 20 and 30% by weight of # 20 fine-grained abrasive having a particle size (count) of 70% by weight, and further, as shown in FIG. An abrasive material and a # 20 fine-grained abrasive material having a particle size (counter) two grains apart from the abrasive material were mixed and mixed in the range of 100 to 0% and 0 to 100% at intervals of 10%.

The structure is 3, that is, the proportion of the abrasive (abrasive grains) in the grindstone is 56% by volume according to the JIS grindstone display method, B is used as the binder, that is, phenol resin, and the grindstone size is Is outer diameter D = 540 mm, thickness T = 30
mm, the diameter d of the hole portion 1a = 177.8 mm.

Further, the grinding conditions are shown in Table 5 below.

[0041]

[Table 5]

As a result, as shown in FIG. 3, 70% by weight of # 14 was mixed with 30% by weight of # 20 fine-grained abrasive having a particle size (counter) of 2 from this, as shown in FIG. It was found that the grinding depth can be maximized and the grinding efficiency (grinding depth) of the grindstone can be further improved in the case of using the above.

When # 14 is 70% by weight and 30% by weight of # 16 fine-grained abrasive which is separated by 1 grain size (count) is used, # 14 is 100% by weight.
The grinding depth was almost the same as when using the abrasive material in which the weight% was used, and no significant change was observed in the grinding efficiency (grinding depth).

Also, # 14 and 2 granularity (counter) than this
When the abrasive mixed with the separated fine-grained abrasive of # 20 is used, the abrasive of # 14 and the abrasive of # 20 are used as shown in FIG.
The mixing ratio with the fine-grained abrasive is (90 to 60% by weight):
It has been confirmed that the setting of (10 to 40% by weight) is effective for improving the grinding efficiency (grinding depth).

Second Embodiment In the first embodiment, the case where the thickness T of the grindstone 1 is 30 mm is shown, but in the second embodiment, the grindstone thickness T is 20 as shown on the horizontal axis of FIG. Grinding in the same manner as in Example 1 was carried out using the grindstone 1 that was varied between ˜75 mm, and the results shown in FIG. 5 were obtained.

As described above, from the viewpoint of the grinding depth, the smaller the grindstone thickness T, the more quickly and in a short time the large amount of grindstone defects can be ground and removed. If the size T is too small, the strength of the grindstone cannot be secured.

Therefore, from the viewpoint of improving the overall grinding efficiency including the grinding depth and the grinding time and the strength of the grindstone, the thickness T of the grindstone is 10 mm or more and less than 50 mm, more preferably 15 mm or more and 45 mm or less, and further desirable. Is preferably 20 mm or more and 40 mm or less.

Example 3 With respect to the characteristics of the fine-grained reinforcing portion 1b of the grindstone 1 for caring for steel pieces shown in FIG. 1, a part of the grindstone 1 of Example 1 was used and the following Tables 6 and 7 are shown. It was carried out and evaluated by using the specifications of the grindstone 1 shown.

[0049]

[Table 6]

[0050]

[Table 7]

Then, using a bending strength measuring test piece (length 110 mm × thickness 10 mm × width 20 mm) having a structure corresponding to the fine grain reinforcing portion 1b around the hole, span: 100 m
When a bending strength measurement test was performed by a three-point bending method at m and a pressing speed of 1 mm / min, as shown in FIG. 6, when the content of the chopped glass fiber exceeded 20% by weight, the chopped glass fiber was added. It was confirmed that the bending strength was rather reduced as compared with the case without the above.

Therefore, when the grindstone 1 having the fine grain reinforced portion 1b around the hole having the specifications shown in Table 7 with the compounding amount of the chopped glass fiber being 20% by weight or less was examined for damage during use, Table 8 The results are shown in.

[0053]

[Table 8]

As is clear from the results shown in Table 8, the fiber content of the hole-surrounding fine-grained reinforcing portion 1b was 2.5 to 20% by weight.
In the above case, damage was not caused depending on the grindstone thickness, and when it was 5 to 15% by weight, both grindstones were not damaged.

Example 4 The structure of the grinding portion 1c of the grindstone 1 is the same as in Example 1 except that the grain size (count) is JISR6001 # 14 / # 20 [70].
% / 30% by weight], and when the grinding stone 1 having the outer diameter D, the grinding wheel thickness T, and the hole diameter d having the relationship shown in Table 9 was evaluated for the flaw removal performance with respect to the steel piece 2, The results are shown in 9.

[0056]

[Table 9]

As shown in Table 9, the outer diameter of the grindstone 1 is 400
If it is less than mm, the flaw removal depth for the steel slab 2 becomes too large, so the outer diameter of the grindstone 1 is 400 m.
It was recognized that it is better to set it to m or more.

[0058]

EFFECT OF THE INVENTION According to the grindstone for servicing steel according to the present invention, the outer diameter is 400 mm or more and the thickness is 10 mm or more.
Since the shape is less than 0 mm, the grinding efficiency at the time of performing the flaw removal of the steel slab can be improved without increasing the grinding pressure, with a small rotary driving force, and without deteriorating the grinding ability (cutness). The significant advantage is that it can be improved.

In some cases, the outer diameter is 400 m.
In the rotary power system, the shape is set to be m or more and the thickness is 15 mm or more and 45 mm or less, and further, the outer diameter is 400 mm or more and the thickness is 20 mm or more and 40 mm or less. It is possible to further reduce the capacity, and it is possible to further suppress the generation of grinding heat, which is a remarkably excellent effect.

Further, in the grindstone for servicing steel according to the present invention, in the abrasive grain size (count) defined in JIS R 6001, different or the same type of fine grain abrasives separated by two grain sizes (count) By using a composition in which 10 to 40% by weight of the abrasive is mixed, a remarkably excellent effect that the grinding efficiency can be further improved is brought about.

Furthermore, according to the grindstone for servicing steel according to the present invention, a fine grain reinforcing portion is provided around the hole of the grindstone,
2.5 to 20 cut glass fiber reinforcing material is applied to the fine grain reinforcing portion.
By having the fine grain reinforcing portion mixed by weight%, a remarkably excellent effect that the strength of the grindstone itself can be further improved is brought about.

Further, in the grinding method for caring for billet according to the present invention, since the grindstone for caring for billet is used to perform rough grinding of the billet, when the flaw removal work of the billet is carried out, the grinding pressure It is possible to efficiently and satisfactorily remove the flaws of steel billet with a small rotational driving force and without deteriorating the grinding ability (sharpness).

Further, in the grinding method for caring for billet according to the present invention, the grindstone for caring for billet is used, and the side surface of the grindstone is inclined at an angle of less than 90 ° with respect to the grinding direction of the billet. Since grinding is performed, the steel slab is efficiently and satisfactorily removed in the state where there are no remaining flaws, and both ends of the ground portion are not folded during the subsequent rolling, and the streaks are left after rolling. It is possible to prevent the generation of grinding powder, and it is possible to prevent clogging of the grindstone by preventing the grinding powder from scattering to the flaw removal part of the steel slab. Be done.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view showing an example of the shape of a grindstone for servicing a steel piece according to the present invention.

FIG. 2 is a plan explanatory view (FIG. (A)) and a side explanatory view (FIG. (B)) showing an embodiment of a grinding method for steel bill maintenance according to the present invention.

FIG. 3 is a graph showing the results of examining the influence of the particle size of the abrasive (abrasive grains) on the grinding efficiency (grinding depth).

FIG. 4 is a graph showing the results of examining the effect of the mixing ratio on the grinding efficiency (grinding depth) when abrasives (abrasive particles) having different particle sizes are mixed.

FIG. 5 is a graph showing the results of examining the influence of the grindstone thickness on the grinding efficiency (grinding depth).

FIG. 6 is a graph showing the results of examining the influence of the content of the reinforcing material used in the fine grain reinforcing portion around the hole of the grindstone on the bending strength.

[Explanation of symbols]

 1 Steel piece maintenance grindstone 1a Grindstone hole portion 1b Fine-grained reinforcing portion of grindstone 1c Grinding portion of grindstone 1d Grinding outer peripheral surface of grindstone 2 Steel piece

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[Procedure amendment]

[Submission date] November 25, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

In this embodiment, Showa Denko Co., Ltd. was used as the abrasive (abrasive grains) that constitutes the grinding portion 1c of the grindstone 1.
Sinter-morundum SR # 10- # 24 (alumina sintered) was used.

Front Page Continuation (72) Inventor Kiharu Kitamura No. 1-36 Noritake Shinmachi, Nishi-ku, Nagoya-shi, Aichi Prefecture Noritake Company Limited Limited (72) Inventor Shigeki Kato 3-chome, Noritake Shin-cho, Nishi-ku, Aichi Prefecture No. 1-36 Noritake Company Limited Limited

Claims (8)

[Claims] 1. An outer diameter of 400 mm or more and a thickness of 10
A grindstone for servicing a steel piece, which has a shape of not less than 50 mm and not more than 50 mm. 2. An outer diameter of 400 mm or more and a thickness of 15
The steel piece maintenance grindstone according to claim 1, which has a shape of not less than mm and not more than 45 mm. 3. The outer diameter is 400 mm or more and the thickness is 20.
The steel piece maintenance grindstone according to claim 1, which has a shape of not less than mm and not more than 40 mm. 4. The abrasive material as defined in JIS R 6001, wherein the abrasive material is a mixture of 10 to 40% by weight of fine abrasive particles separated by 2 particle sizes (counts). A grindstone for servicing a steel piece according to any one of 1. 5. An abrasive having a particle size (count) defined by JIS R 6001 in which 10 to 40% by weight of fine particle abrasives of the same kind separated by 2 particles (count) are used. A whetstone for caring for the steel piece described in. 6. A fine grain reinforcing portion is provided around the hole of the grindstone,
2.5 to 20 cut glass fiber reinforcing material is applied to the fine grain reinforcing portion.
The grindstone for caring for a steel piece according to any one of claims 1 to 5, which has a fine-grained reinforcing portion mixed by weight%. 7. A grinding method for caring for a steel piece, which comprises roughly grinding a steel piece using the grindstone for caring for a steel piece according to claim 1. 8. Grinding using the grindstone for caring for a steel piece according to claim 1, wherein the side surface of the grindstone is inclined at an angle of less than 90 ° with respect to the grinding direction of the steel piece. The characteristic grinding method for caring for steel pieces.