JP2867301B2 - Grinding wheel for billet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grindstone for maintaining a billet, and more particularly, to a grindstone whose grain size distribution is adjusted based on the grain size distribution standard of a grindstone specified in JIS R6001. The present invention relates to a slab maintenance whetstone, comprising: a slab maintenance whetstone;

[0002]

2. Description of the Related Art For example, the abrasive grains of a wrought stone are JI.
It is prepared according to the abrasive grain size distribution specified in SR6001. This particle size distribution is in accordance with JIS R 60
As shown in the abrasive grain size distribution of No. 01, the ratio of the abrasive grains to each sieve is defined, and a part thereof is as shown in Table 1 of the separate sheet.

For example, in the case of # 14 in Table 1, the diameter of the two-stage sieve is 1.70 mm, and the diameter of the three-stage sieve is 1.40 m.
m, the particle size is less than 1.70 mm to 1.40 mm
Abrasive grains in the above range are 45% or more, and the two-stage sieve diameter is 1.
70mm, the sieve diameter of the four stages is 1.18mm,
In the total of three stages and four stages, the particle size is less than 1.70 mm to 1.1.
It is stipulated that the abrasive grains in the range of 8 mm or more remain at 70% or more, which prevents the entry of coarse grains and fine grains. That is, the fact that the abrasive grains of 1.70 mm or more in the second stage are 20% or less means that all the abrasive particles pass through the first stage sieve, so that the abrasive particles of 2.36 mm or more Although not included, fine particles of less than 1.00 mm passing through the fifth stage may contain up to 3%. An example is shown in Table 2, in which the parentheses indicate the diameter of the standard sieve of each stage.

[0004]

[Table 1]

[0005]

[Table 2]

[0006] A steel slab is ground using a grindstone made of abrasive grains having a grain size distribution conforming to the JTS standard, and sufficient scale-off is not performed in a heating furnace such as a precision rolled material or a decarburized material. If the unrolled product is rolled as it is, a product that has been rolled with a particularly small total surface reduction will have flaws in the grindstones (grain flaws).

[0007] Thus, if the grain size of the abrasive grains is reduced within the range of the JIS standard, the remaining grindstone flaws are reduced.
As shown in FIG. 5A, the life of the grindstone becomes shorter as the abrasive grains become finer. In order to prevent this, the abrasive grain count is selected by balancing the two. However, in this case, the number of required counts is increased, and there is a problem that a facility stop loss required for changing a grinding wheel occurs, thereby deteriorating facility efficiency.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. Specifically, the present invention aims at narrowing or uniforming the grain size distribution of abrasive grains so as to improve the roughness of the surface of the billet. It is an object of the present invention to propose a whetstone for maintaining a steel slab, which can improve wrinkles, prevent the generation of flaws in the whetstone on a product, and can maintain the whetstone life equal to or higher than that of a conventional coarse grain.

[0009]

Means for Solving the Problems That is, the present invention provides:
This is a whetstone for preparing a steel piece, comprising abrasive grains having the same grain size as JIS R 6001.
In the grain size sieve of 6001 abrasive grains, 90% or more of the abrasive grains remaining on the third and fourth stages of sieves are 2% or more.
It is characterized in that the abrasive grain remaining in the sieve of the stage is 5% or less.

Hereinafter, the configuration as the means of the present invention and the operation thereof will be described in detail as follows.

The present inventors have found that conventional JIS standard grinding stones cannot be sufficiently scaled off in a heating furnace as in the case of precision rolled material, billet of wire rod material such as coal control material, etc. When a rolled product with a small amount of surface reduction is ground with a grindstone using abrasive grains having a particle size distribution of JIS standards, a grindstone flaw is generated on the product.

In the case of a whetstone, generally speaking, FIG.
There is a relationship shown in (a) and (b). That is, as the particle size changes from fine to coarse, the life is prolonged in linear proportion. On the other hand, the surface roughness becomes smaller as the size becomes coarser to finer, and tends to change from a rough surface to a fine surface.

Therefore, the present inventors, as described above,
We focused on the fact that the width, that is, the range of the grain size distribution of the abrasive grains of the grindstone specified in the JIS standard was too wide, and was unsuitable for grinding the above-mentioned rolled product. As a result, even if the grindstones have the same grain size, if the grain size distribution of the abrasive grains constituting the grindstones is readjusted in accordance with the grinding of the above-mentioned rolled product, the grindstone remaining flaws can be prevented, and the life of the grindstone and the billet can be reduced. It has been found that the relationship of surface roughness (surface roughness Rmax) can be improved.

[0014] Based on such a point, the present invention relating to a slab maintenance wheel has been established.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a whetstone for preparing a slab, wherein the abrasive grains constituting the whetstone have the same grain size as a whetstone of a JIS standard product (JISR 6001) used for maintenance of a rolled product such as a slab. Belongs to the abrasive grains. However, the particle size distribution of the constituent abrasive grains is adjusted to a narrower width than the particle size distribution specified in JIS R 6001 and has a more uniform particle size distribution. When composed of abrasive grains having such a particle size distribution, the grindstone can be an excellent grindstone as compared with a grindstone using an abrasive grain having a grain size distribution of JIS standard (JIS R 6001).

In order to further adjust the width of the grain size distribution according to the JIS standard (JIS R 6001) and form a grindstone with the abrasive grains having this distribution, two types of adjacent steps in the sieve having the grain size distribution of JIS R6001 are used. The abrasive grains remaining on the sieve are set to 90% or more, and the abrasive grains remaining on the sieves of larger sieves are set to 5% or less.

That is, the JIS standard (JIS R 6
In the case of abrasive grain # 14 (No. 14 grinding stone) of No. 001), the abrasive grain remaining in the range of 1.18 mm or more to less than 1.70 mm, that is, the third and fourth stages, is made 90% or more. 70 mm or more and less than 2.36 mm, that is, 2
Abrasive grains remaining in the step are kept to 5% or less. Also, JI
In SR6001, abrasive grain # 20 (20th whetstone)
In the case of, the mesh is 0.85 mm or more to 1.18 mm
Is less than 90%, that is, 90% or more, and 1.18 mm or more and 1.70 or more.
mm, that is, 5% or less, preferably 0, of the abrasive grains remaining in the second stage.

In the case of a grindstone composed of abrasive grains having a particle size distribution as described above, it is possible to prevent grindstone residual flaws, which is a conventional problem. Particularly, abrasive grain # 16 (No. 16 whetstone) of JIS R 6001 which has been conventionally fine grain
In this case, it is possible to prevent the remaining scratches on the grindstone, which has become a problem, and the service life is as long as that of abrasive grain # 10 (No. 10 grindstone) which belongs to the class of coarse grains in JIS R6001.

As described above, the use of the grindstone according to the present invention is effective for grinding the billet surface of a wire rod material.
The present invention is not limited to this, and can be applied to other fields.

In particular, a preferable effect in this field is that abrasive grains of a grindstone have a particle size distribution of JI
In the sieve of the grain size distribution of the abrasive grains of SR 6001,
As shown in Abrasive Grain # 14, the abrasive grains that remain in the third and fourth sieves account for 90% or more, and the abrasive grains that stay in the second stage stay below 5%. is there. Further, even in the case of such a configuration, the effect becomes more remarkable if the abrasive particles are formed from particles whose particle size distribution remains in the second stage and whose width is adjusted to be narrower.

As described above, JIS R 60
In the sieve having the abrasive grain distribution of No. 01, the abrasive grains remaining in the third-stage sieve can be 90% or more, and the abrasive grains remaining in the second-stage sieve can be 5% or less, preferably zero. For example, abrasive grain # 14 of JIS R 6001 (14th whetstone)
When the whetstone is manufactured with only the abrasive grains of 1.40 mm or more and less than 1.70 mm remaining at the third stage in the sieve, that is, 100% (the abrasive particles remaining at the second stage are 0%), Abrasive grain # 16 (16
No. 2 whetstone) can also prevent the problem of the remaining whetstone marks.

Also, abrasive grains # 14 made of abrasive grains whose grain size distribution has been adjusted to only those having the third stage as described above
(No. 14 whetstone) improves the roughness of the grit surface as compared with the case where the abrasive grains remaining at the second stage of 1.7 mm or more are suppressed to 5% or less.

Embodiment 1 The abrasive residual ratio with respect to the particle size distribution shown in FIG. 1, and the average value and range are respectively X = 1.47 mm, R = 1.70-0.85 mm
# 14K of the example was prepared from an abrasive mixture having a ratio of 95% or more. For comparison, the abrasive particle residual ratio with respect to the particle size distribution shown in FIG. 1, and the average value and range are respectively X = 1.45 mm, R = 2.36-0.85 mm.
A grindstone was prepared using an abrasive mixture JIS # 14. The work material (S45C-S53C) was ground with these grindstones, and the surface roughness (Rmax), the grindstone life and the grain crack generation rate were investigated. The results are shown in FIGS. 2 and 3, respectively.
And shown in FIG.

Embodiment 2 The abrasive residual ratio with respect to the particle size distribution shown in FIG. 1, and the average value and range thereof are respectively X = 1.52 mm and R = 1.70 to 1.18 mm.
The grinding was performed in the same manner as in the example except that the grinding stone of # 14K of the example was prepared from the abrasive grain mixture of Example 1. The results are shown in FIGS. 2, 3 and 4.

Embodiment 3 The particle size distribution of the JIS # 20 whetstone was changed to a particle size distribution range of 1.18 to 0.85 mm of 90% or more, and # 20K of the example of 1.18 mm to 5%.
Example 2 was performed except that the grindstone was prepared. The results are shown in FIGS. 2, 3 and 4.

As described above in Examples 1 to 3, the grindstone according to the present invention has a surface roughness (Rmax) of a slab that is smaller than that of a conventional grindstone made of abrasive grains having a grain size distribution conforming to JIS.
Is improved, the generation of grinding stone residue is prevented, and the life is equal or equal to or more than that. It can be seen that the grinding stone according to the present invention is excellent.

A similar test was performed for grinding wheels # 10 and # 16 using abrasive grains having a particle size distribution conforming to JIS standards, and the results are shown in FIGS. 2, 3 and 4.

According to these results, the life of the grindstone of the embodiment of the present invention is improved to be equivalent to that of a coarse grinding wheel of the JIS standard whetstone, and the surface roughness of the work material after grinding is JIS.
It is improved to a finer grinding stone than a standard product, and it becomes possible to integrate the grinding wheel.

[0030]

As described above in detail, the present invention is configured by adjusting the grain size of the abrasive grains as described above. Generation can be prevented and the life of the grinding wheel can be improved.

In addition, with such a configuration, it is possible to integrate the wheel numbers of the owned grinding stones, and it is possible to greatly reduce the equipment stop loss due to the replacement of the grinding stones.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the particle size distribution of abrasive grains and the residual ratio of abrasive grains in Examples of the present invention and conventional examples.

FIG. 2 is an explanatory view showing a state of a surface roughness (Rmax) of a steel slab when being ground with a grindstone according to an embodiment of the present invention and a conventional example.

FIG. 3 is an explanatory diagram of a grinding wheel life of an example of the present invention and a conventional example.

FIG. 4 is an explanatory diagram of the rate of occurrence of remaining grindstone flaws in the example of the present invention and the conventional example.

5 (a) and 5 (b) are graphs respectively showing the relationship between the grindstone particle size and life, and the relationship between the grindstone particle size and surface roughness.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Haruyuki Imamura 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi, Okayama Pref. Kawasaki Steel Corporation Mizushima Works (72) Inventor, Toyohisa Tokumaru Mizushima-Kawasaki-dori, Kurashiki-shi, Okayama 1-chome (without address) Kawasaki Steel Corporation Mizushima Works (72) Inventor Tomomi Tashiro 1-chome, Mizushima-Kawasaki-dori, Kurashiki City, Okayama Prefecture Kawasaki Steel Corporation Mizushima Works (72) Inventor Toshio Sakamoto 1-chome, Mizushima-Kawasaki-dori, Kurashiki City, Okayama Prefecture (without address) Kawasaki Steel Corporation Mizushima Steel Works (72) Inventor Masahide Shimooka 2-3-20 Yoshiura Shinmachi, Kure City, Hiroshima Prefecture Creno-Ton Corporation Kure Works (72) Inventor Katsuyuki Chiba 1 Shimotagawa, Okamachi, Okazaki City, Aichi Prefecture Nagoya Elastic Tooth Co., Ltd. (72) Inventor Hiroto Kobayashi Ai Noritake Campani-Limited Jinmori Plant, No. 16 Jinoricho, Tsushima City, Chishima Prefecture, Japan (56) References JP-A-49-61212 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , (DB name) B24D 3/00 330

Claims (2)

(57) [Claims] Claims 1. A whetstone for preparing a steel slab comprising abrasive grains having the same grain size as JIS R 6001, wherein the abrasive grains of the abrasive grains are the third and fourth stages in a grain size sieve of JIS R 6001 abrasive grains. 90% of the grains stay on the sieve
Above, the abrasive grain for staying in the second stage sieve is 5% or less, characterized by the fact that the grinding wheel for maintaining a billet is characterized in that it is 5% or less. 2. A steel whetstone comprising abrasive grains having the same grain size as JIS R 6001, wherein the abrasive grains of the grindstone remain at the third stage of the grain size sieve of JIS R 6001. A grinding wheel for maintaining a billet, characterized in that the abrasive grains are 90% or more and the abrasive grains remaining in the second-stage sieve are 5% or less.