JPS6018249B2 - Rolling roll with strong neck part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the provision of a roll having a new structure that is most suitable for a rolling roll having an elongated neck shape, a special shape requiring particular toughness at the neck end, and usage characteristics. .

Generally, rolling rolls consist of a chest and a neck.
The body portion is formed of 8 outer shell portions and a body core portion which is integrally cast concentrically with the protective outer shell portion, and the neck portion has moon concentric portions on both sides of the 8 core portions. It is formed of a bearing part that is integrally cast with the bearing part, and neck end parts that are integrally cast on both sides of the bearing part.

In recent years, in hot strip mills for rolling steel plates, new types of rolling rolls with neck shapes and usage conditions different from conventional ones have been researched and developed in order to control the shape of steel plates. In other words, these methods include a method of shifting (moving) the work roll in the axial direction, a method of forcibly suspending the work roll, a method of crossing the two work rolls with respect to the marking line of the backup roll, etc. This is what we provide. However, work rolls used in these rolling methods tend to have smaller body diameters.

Furthermore, due to the type of rolling mill, the length of the neck portion must be longer than that of conventional rolls, and the diameter of the neck portion must also be reduced. In addition, in this type of roll, greater stress is generated in the neck portion than in the past, and particularly strength is required. The conventional general shape roll is shown in Figure 1, and the special shape roll used for the above new rolling method is shown in Figure 2 in comparison, and the specific differences in shape and dimensions are summarized as follows. .

SoN ZoN/〆B DN
N UN B Conventional.

→Ke next 1000~1400 0.52~0.7
5 340~500 2.0~3.6 650
~840 years Todama Ronori neighbor dog 1500~2000
0.80~1.20 130~330 3-8~
13.0 500-760 SoN: long neck)〆B
: long body) DN: neck end diameter (willow) DB: body diameter (class ■) As mentioned above, the rolls used for this new rolling method are
Generally, the ratio of neck length to torso length IN/18 is 0.8 to 1.2,
Or the ratio IN/DN of neck length and neck diameter is 3.8 to 13.
．． It is characterized by having an elongated neck shape in which one or both of the neck ends has a smaller diameter than the bearing part.

By the way, the required characteristics of the neck part of such a specially shaped rolling roll are different depending on the part in the vertical direction, and the bearing part 2 near the arm part 1 needs to have wear resistance and strong balling properties against friction with the bearing. On the other hand, the neck end 3 remote from the body 1 is elongated in shape and requires particularly strong balling properties because it needs to withstand large stresses.

In addition, with this specially shaped roll, as shown in Figures 2 and 3, there is a part of the neck end 3 that is longer in diameter than the neck end DN, and depending on the rolling method, for example, the working side W A large thrust stress is generated on the driving side D, and a large sinking stress is generated on the drive side D, so this part requires particularly strong toughness.

In this way, the present invention has a neck length to torso length ratio of IN/18 of 0.
．． 8 to 1.2, or the ratio of neck length to neck diameter IN/DN
Targeted at special rolling rolls that have an elongated neck shape with a diameter of 3.8 to 13.0 and generate large stress at the neck end, the chest and bearing parts are made of adamite to suit the usage characteristics. To provide a new roll structure in which one or both of the neck ends are formed of a strong core made of a different material from the body and the bearing, and both are welded and integrated. It is.

For work roll middle and front stands used in secondary hot strip mill finishing stands, single-piece cast Adamite rolls having the following chemical components are generally used.

Chemical composition (wt%) ○ Si Mn P S Ni
○r Mo V Nbl. 5-2.0
0.3-1.0 0.5-1.5 0.0 Bekkushita 0.0 Bekkushita 0.2-2.0 0.5-3.0
0.2 to 1.0 20 or less 2.0 or less This unit Adamiteroll is intended to impart roughness, abrasion resistance, and crack resistance to the chest, and Hs45
It has a hardness of ~65.

Furthermore, in conventional rolling mills, the neck length IN is not very long and the neck flea DN is quite large, so even if the neck part is formed integrally with the same material as mentioned above, which is aimed at the use characteristics of the body part, there is no problem in terms of strength. It didn't happen. Incidentally, the neck strength of this type of unit roll is as follows. Tensile strength of neck end of single Adamite roll 40-55
k9/fence elongation 0.3 to 1.5% However, as a result of intensive research by the present inventors, when a conventional roll is applied as it is to a roll for the shape intended by the present invention, the neck end It was found that due to insufficient strength in part 3, it could not withstand use at all.

In other words, the technical means of forming the roll neck portion from the same material as in the case of a follower cannot be an effective means of manufacturing the desired roll. In addition, since the rolling roll according to the present invention has a long and narrow neck, if the entire body is integrally cast like a single Adamite roll, a deep shrinkage cavity-like defect will occur at the neck end along the roll axis. It was difficult to manufacture.

Therefore, in the present invention, as shown in FIG. 4, the chest 1 and the bearing part 2 are integrally formed of the above-mentioned Adamite material as in the case of the conventional single roll, while the neck end is required to have even stronger rolling properties. One or both of the parts 3 are made of a tough rice material different from that which forms the chest part 1 and the bearing part 2, and the body part 1, the bearing part 2, and the neck end part 3 are made of different materials. are welded and integrated to form a roll.

The tough material forming the neck end 3 is superior in strength, elongation, etc., at least to the conventional single Adamite roll. In other words, it has a hardness of about iHs30-48 and at least 55k9/
It is necessary that the material has a tensile strength of 1.5% or more and an elongation of 1.5% or more. An example of a suitable strong material suitable for such purposes is a so-called low carbon material with the following chemical components.
Adamite wood is displayed.

Chemical composition (wt%) 〇 Si Mn P S N
j 〇r M.

B. So0.5,~1.4 0.3~1.0 0.
5 to 1,5 0.05 or less 0.05 or less 1.0 or less 0.5 to 2.0 0.5 or less Fe and the reason for limiting the components of the above material forming the neck end 3 Let's talk about. If C is less than 0.5%, the castability is poor, and although the toughness is good, the hardness becomes too low;
% or more, the ballability becomes insufficient.

Si is necessary in an amount of 0.3% or more from the viewpoint of deoxidizing the molten metal and its properties, but if it is 1.0% or more, the toughness will be insufficient.

Mn is contained in an amount of 0.5% or more to deoxidize the molten metal, but if it is 1.5% or more, the plowability is still insufficient.

It is desirable that P and S be as small as impurities, 0.05%.
This is because the above-mentioned condition inhibits ballability. Ni'ma 1.0%
This is because the material base becomes hard and the quality deteriorates. This is because a content of Cr in the range of 0.5 to 2.0% is suitable for ensuring toughness, and a content of 2.0% or more is uneconomical.

This is because if Mo exceeds 0.5%, it becomes hard and the grade quality deteriorates. The low C adamite material with the above-mentioned specific components can satisfy both the required tensile strength of 55 kg/kg or more and elongation of 1.5% or more, and the eye part 1 and the bearing part 2
Since the material is similar in composition to the material that forms it, its weldability is also good, making it suitable for the intended purpose of a strong rice village.

Regarding the hardness of the tough material forming the neck end 3, it is better not to be too high in order to ensure strong balling properties, but on the other hand, there is also the problem of rotational wear. is appropriate. The hardness of the above-mentioned low Ca damite material approximately falls within this hardness range. The so-called high C adamite material used to form the body part 1 and the bearing part 2 has a relatively large amount of alloy, so it has been heat treated to have a hardness of Hs4.
Of course, it is possible to easily achieve a feed temperature of 5 to 6 degrees Fahrenheit, thereby meeting required properties such as abrasion resistance. In addition to the above-mentioned low C adamite, the material used for forming the neck end portion 3 in the present invention may be selected from known roll materials depending on conditions such as weldability and economical efficiency, as long as it has the necessary toughness. You can choose.

Next, a method for manufacturing a roll according to the present invention will be briefly described.

In casting the roll of the present invention, the body part 1 and the bearing part 2 are cast in the same manner as in the case of manufacturing a conventional single Adamite roll.
It is convenient to cast the neck end 3 in one piece at the same time and then use a separate molten tough material to cover the neck end 3. Alternatively, the neck end 3 may be disposed on the lower mold side and cast in advance, and then the body 1 and the bearing 2 may be cast in such a manner that both parts are exchanged. In any case, if both the left and right neck ends 33 are made of different materials and strong materials, these are keyed and welded to the same part 1 and the bearing part 2, respectively, and only one neck end 3 is made of different materials and made of strong materials. If it is made of Liu material, only one of the parts is made of body part 1.
and the bearing part 2, and the other part may be integrally cast using the same material as the arm part 1 and the bearing part 2. In this way, in the present invention, the body part 1, the bearing part 2, and the neck end part 3 are separately cast and integrated, so that the deep shrinkage cavity-like defects that occur in the neck end part 3 when these are integrally cast are avoided. Moreover, since the bearing part 2 is thicker and has a larger heat capacity than the neck end part 3, if the neck end part 3 is integrally cast with the end face of the bearing part 2, the adhesion property will be extremely good. After the neck portion is integrally cast with different materials in the axial direction in this way, the entire roll is subjected to diffusion heat treatment as in the conventional method, followed by normalization or competitive heat treatment on the chest 1, and finally strain relief heat treatment.

The neck machine part 3 formed of this cutting board and tough material is separately heat treated to improve the tough rutting property while taking care not to introduce the hardening effect. The present invention will be described with reference to specific embodiments.

*8 Same flea DB6500, body length IB1700, neck length DN215, neck length IN1800, i.e. IN/IB=
1.06, IN/DN=8.37, with a shape as shown in FIG. A rod was cast using the following chemical components, with only one neck, Oribe, made of a different strong material. Chemical composition (wt%) ○ Si Mn P S Ni
0r Mo' same part and bearing part 1.62
0.54 o. 93 o. o24 o. oo9
0.80 1.12 0.58 One neck end times the other neck end 1.14 0.53
0.88 0.014 0.008 0.2
5 1.02 0.13 After casting, the diffusion heat treatment was followed by normalization heat treatment for only one cylinder, and then strain relief heat treatment.

As a result, the roll body is made of a material with a hardness of 51 to 53 Hs and excellent roughness resistance, while one neck end has a hardness of 38 to 42 Hs and a tensile strength of 71 to 74k.
9/The fence was formed to have excellent strength and elongation of 21 to 24%. FIG. 5 shows the microscopic structure 2 of the thorax, and FIG. 6 shows the microscopic structure of the strong neck end. Note that the mirror joints of both pieces were perfectly connected, and were sound with no defects. As described above, in the present invention, the body and the bearing are integrally formed of adamite material, one or both of the neck ends are formed of a different strong rutting material, and the two are welded and integrated to form a roll. Because of its structure, it can be used for new types of rolls that have elongated necks and generate large stress at the neck ends, which could not be handled by single rolls with auxiliary shafts. While each part satisfies the necessary properties, the neck end can be given sufficient strength to meet the usage conditions.

In addition, since the ear part, bearing part, and neck end are separated and integrally cast, deep shrinkage defects do not occur in the neck machine part even if the neck part is long and thin, and the bearing part is molded at the neck end. The rolling roll according to the present invention is thicker than the bearing part and has a larger heat capacity.
The neck end is welded to the bearing part very well.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing an example of the shape of a conventional rolling roll, and FIG. 2 is a side view showing an example of the shape of a rolling roll to which the present invention is applied.

FIG. 3 is a partially enlarged side view of a rolling roll to which the present invention is applied, and FIG. 4 is a half-sectional side view showing an example of the structure of the rolling roll according to the present invention. 5 and 6 are micrographs showing the structure of an example of the composite roll according to the present invention, in which FIG. 6 shows the same part of 8 and FIG. 6 shows the neck end. 1... Ear part, 2... Bearing part, 3... Neck end.

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A body part is formed by a body core part that is integrally cast concentrically with the body outer grain part, and bearing parts are integrally cast with the body core part on both sides of the body core part. In a rolling roll in which a neck portion is formed by a neck end portion integrally cast on both sides of the bearing portion, the ratio of the neck length l_N to the body portion l_B is
l_N/l_B is 0.8 to 1.2, or the ratio of l_N to neck end diameter D_N is 3.8 to 13.0, and one or both of the neck ends have a smaller diameter than the bearing part. The body and the bearing are integrally cast from adamite material, one or both of the neck ends are made of a tough material different from the body and the bearing, and one or both of the neck ends are made of a tough material different from the body and the bearing. The toughness that forms both is hardness H_s30~48,
A rolling roll with a strong neck portion characterized by a tensile strength of 55 kg/mm^2 or more and an elongation of 1.5% or more. 2 The tough material forming the neck end is: C: 0.5-1.4% S: 0.05% or less Si: 0.3
~1.0% Ni: 1.0% or less Mn: 0.5-1.5%
Cr: 0.5-2.0% P: 0.05% or less Mo: 0.
A rolling roll having a strong neck portion according to claim 1, which is a low C adamite material containing 5% by weight or less, and the balance being Fe and impurities.