JPH05245513A - Horizontal roll for hot rolling shape steel - Google Patents

Abstract

PURPOSE:To improve the corner chipping resistance and wear resistance in a horizontal roll for hot rolling an H-shape steel or the like. CONSTITUTION:The trunk part of the horizontal roll is a multiple laminated layer body in which a high-speed steel sintered alloy layer 13 is formed at the peripheral face and/or the end face of a base material 12. The high-speed steel sintered alloy layer 13a and 13b formed at the peripheral face or the end face may be substituted with a hard member 14a and a wear resisting member 14b and, furthermore, according to the actual working conditions, the sintered alloy layer is formed at only one of the peripheral face or the end face and the other is the laminated layer structure in which the original surface of the base material 12 is exposed in some cases. The sintered alloy layer is formed by the hot still water isotropic pressurizing sintering and the boundary between each member is combined rigidly by the diffusion joining.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal roll excellent in corner chipping resistance and wear resistance used in hot rolling of H-section steel and the like.

FIG. 8 shows hot rolling of a wide flange type steel material such as an H type steel material. Reference numerals 10 and 10 denote horizontal rolls which are vertically arranged to sandwich the web a of the rolled material w, and vertical rolls 20 and 20 which roll down the flange b of the rolled material w are disposed on both sides thereof. The web a of the rolled material w is subjected to reduction by the upper and lower horizontal rolls 10 and, and the left and right flanges b and b are horizontal rolls 10 and 10.
Is rolled between the end surface and the vertical rolls 20, 20. As the horizontal roll 10, nickel glen cast iron rolls (C: 3.1 to 3.5%, Si: 0.5) have been conventionally used.
-1.5%, Mn: 0.2-1%, Ni: 3.5-4.
5%, Cr: 1-2%, Mo: 0.2-0.7%, F
e: Bal), or an adamite cast iron roll (C: 1.
7-2.2%, Si: 0.5-0.9%, Mn: 0.7
~ 1.1%, Ni: 1.5-2%, Cr: 0.8-1.
2%, Mo: 0.6 to 1.0%, Fe: Bal) and the like have been used. Nickel Glen cast iron rolls have high hardness (Hs: about 75) and excellent wear resistance, while adamite cast iron rolls have good ductility (Shearpy impact value (no notch): about 1.3 kgf · m / cm ² ). Have

[0003]

In the hot rolling operation of a wide flange type steel material, the roll barrel portions of the horizontal rolls 10 and 10 are subjected to a heat load due to the contact of the rolled material w and the ridge portions ( Since the rolling loads of the web a and the flange b are superposed on the corner a), the corner is often prone to cracking and damage due to the progress thereof, while the end face of the body part is worn by the pressure sliding contact of the flange b. It is easy to cause thinning. If the roll shape is impaired in the roll body due to the loss of the corner rounded portion or the thinning of the side surface, it hinders the smooth execution of the hot rolling operation, and causes a defective shape of the obtained rolled product. Therefore, the roll body has high ductility and has excellent resistance to chipping of the corner rounded portion (corner chipping resistance), high hardness, and excellent resistance to abrasion. Is required.

However, wear resistance and ductility are generally reciprocal material properties, and it is difficult to satisfy both high wear resistance and ductility at the same time. The conventionally used adamite cast iron roll has good ductility, but since it is soft (Hs: about 60), the sliding contact friction of the flange b of the rolled material w on the body end face is strong. Under such a usage condition, the wear reduction of the end face is likely to proceed and seizure due to friction is likely to occur. On the other hand, the Nickel Glen cast iron roll has excellent wear resistance and seizure resistance, and has poor ductility (Shearpy impact value (no notch): about 0.2
Since it is 7 kgf · m / cm ² , there is a drawback that the corners are likely to be damaged when, for example, a strong reduction is performed or a cooling failure occurs. Therefore, the present invention provides a horizontal roll for wide flange type steel hot rolling, which has high ductility and toughness capable of preventing cracking and chipping of the corner round portion and high wear resistance capable of preventing wear damage to the end face. To do.

[0005]

Means and Actions for Solving the Problems A horizontal roll for hot rolling of a shaped steel of the present invention is a high speed steel in which a roll body is laminated and formed on a substrate as a hot isostatic pressing body. It is characterized by having a peripheral surface and / or an end surface made of a sintered sintered alloy.

The horizontal roll of the present invention will be described below with reference to the drawings showing an embodiment. In FIG. 1, 12
Is a body member having a roll shaft hole 11 at its axis, 13
Is a high-speed steel-based sintered alloy layer laminated on the outer periphery of the base material 12. The base material 12 and the high speed steel-based sintered alloy layer 13 have a concentric circular laminated structure.

The high-speed steel-based sintered alloy layer 13 laminated on the base material 12 may be of any material specified in JIS G4403, but is not limited thereto. The chemical composition of the high-speed steel-based alloy applied to the present invention is not restricted by the restrictions as in the case of cast alloys, for example, the selection and combination of additive elements so as not to impair the castability, and therefore the freedom of component design. High degree, for example, C: 1.
5 to 3.5%, Si: 0.3 to 3.5%, Mn: 0.2
~ 0.6%, Cr: 3-8%, Ni: 3% or less, Mo:
3-9%, W: 5-14%, Co: 14% or less, Fe:
Bal, having a chemical composition in which a part of Fe is optionally substituted by 11% or less of one or more elements selected from V, Ti, and Nb (total amount in the case of composite addition of two or more elements) The thing etc. can be applied.

The high-speed steel-based alloy is a high-strength, high-hardness alloy, and is subjected to high pressing force (for example, 800 to 1500 kgf / cm ² ) evenly by hot isostatic pressing (HIP sintering). The high-speed steel-based sintered alloy formed in is extremely dense. Its shearpy impact value (no notch) is about 1k
gf · m / cm ² or more and excellent corner toughness due to high ductility comparable to that of adamite cast iron roll (about 1.1 kgf · m / cm ² ), and its hardness (Hs) is about 80 or more. , Nickel Glen Cast Iron (Hs:
It has a higher degree of abrasion resistance than about 75). Also,
It has excellent toughness with a tensile strength of about 100 kgf / mm ² or more and an elongation of about 1% or more.

The high-speed steel-based sintered alloy layer 13 has a role of protecting the surface of the roll body from abrasion due to contact of the rolled material w, and a function of preventing corner chipping.
It is not always necessary to have a uniform layer thickness over the entire axial direction of the base material 12 as shown in FIG. 1, and as shown in FIG. Needless to say, the sintered alloy layer 13a and the sintered alloy layer 13b, which is the surface layer of the end surface where the flange b of the rolled material w is in sliding contact, are laminated on the base material 12. The layer thickness of the sintered alloy layers 13a and 13b may be, for example, 10 to 50 mm.

In the roll body shown in FIGS. 1 and 2, the peripheral surface and the end surface are made of a high speed steel-based sintered alloy having high ductility and wear resistance. 12
Does not require high ductility and high wear resistance, and its grade is
Cr-Mo steel (JI
SG 4105) or the like, or ductile cast iron (C: 3.1 to 3.7%, Si: 1.2 to 2.3).
%, Mn: 0.2 to 0.8%, Ni: 1.5% or less, C
r: 0.5% or less, Mo: 0.1 to 0.4%, Fe: B
al) or the like.

In the example of FIG. 2 described above, the structure in which the peripheral surface layer and the end surface surface of the roll are the sintered alloy layers is shown. However, the peripheral surface surface sintered alloy layer 13a or the end surface sintered alloy layer 13b is shown.
It is also possible to adopt a structure in which one of the two is replaced by a member of another material type. An example thereof is shown in FIGS. FIG. 3 shows that the high speed steel-based sintered alloy layer 13a is formed on the surface of the peripheral surface to ensure wear resistance and corner chipping resistance of the peripheral surface, while the end surface has a hard metal plate member 14b (such as nickel-grain cast iron). This is an example in which the surface layer is formed of a donut plate shape to ensure the wear resistance of the end surface. On the other hand, in FIG. 4, a high-speed steel-based sintered alloy layer 13b is formed on the end face to secure its wear resistance, and a surface layer made of adamite cast iron or another cylindrical member 14a made of ductile toughness material is provided on the peripheral face. This is an example in which it is formed to ensure corner resistance.

Further, in the horizontal roll of the present invention, the material type of the base material 12 is appropriately selected according to the usage conditions in an actual machine and the degree of demand for the corner chipping resistance and the end surface wear resistance. As shown in FIGS. 5 and 6, the high-speed steel-based sintered alloy layer was formed only on one of the peripheral surface layer and the end surface layer of the base material 12, and the dough of the base material 12 was exposed on the other surface. It can also be a structure.

In FIG. 5, a high wear resistant material is applied to the base material 12 to form the high-speed steel-based sintered alloy layer 13a only on the peripheral surface, and the end surface is made of the material of the base material 12 as it is. In this example, the receiving surface of the flange b of w is used. The high wear-resistant material of the base material 12 is, for example, nickel glen cast iron, and is also ductile cast iron, particularly high hardness ductile cast iron (C: 3.1 to 1).
3.5%, Si: 1.2 to 1.8%, Mn: 0.2 to
0.8%, Ni: 1.5 to 3.0%, Cr: 0.3 to
1.0%, Mo: 0.2 to 0.7%, Fe: Bal)
Also, since it is a material having hardness (Hs) of about 60 to 70 and good wear resistance against sliding contact wear of the rolled material flange b, it is suitable as a base material for a roll body having this laminated structure.

FIG. 6 shows an example in which the high-speed steel-based sintered alloy layer 13b is formed only on the end face of the base material 12, and the peripheral surface of the base material 12 is a pressing surface against the web a of the rolled material. Is. As the base material 12, adamite cast iron can be applied, and ductile cast iron, particularly tough ductile cast iron (C: 3.3 to 3.7%, Si: 1.7 to 2.3%,
Mn: 0.3-0.7%, Ni: 0.7-1.1%, C
r: 0.1 to 0.2%, Mo: 0.2 to 0.3%, F
e: Bal) also has high ductility (Shearpy impact value (no notch): about 0.9 kgf · m / cm ² ),
It is useful as a base material for a body of this laminated structure.

The outer shape of the roll body of the present invention is not limited to that shown in each of the above figures, and corresponds to a reduction schedule such as rough rolling, intermediate rolling or finish rolling in the rolling process of wide flange type steel, or Depending on the product shape, for example, it may be designed to have a side surface having a taper as shown in FIG.

The body of the horizontal roll of the present invention comprises the substrate 12
And a high-speed steel-based alloy powder that is a sintering raw material for forming a high-speed steel-based sintered alloy to form the peripheral surface layer or the end surface surface layer (in the case of the laminated structure shown in FIGS. 3 and 4, Along with the sintering raw material powder, the peripheral surface layer member 14a or the end surface layer member 1
4b built-in), degassing and sealing (eg 1 × 10 ^-1 Tor)
r), and then hot isostatic pressing under pressure (HIP treatment). Pressing force is about 8 for HIP processing
00 to 1500 kgf / cm ² , temperature about 800 to 12
The temperature is set to 00 ° C. and the heating / pressurizing is performed for an appropriate time (for example, 1 to
4Hr) hold successfully achieved. The base material 1 is formed by diffusion bonding that occurs during the heating / pressurizing process.
2, the sinter alloy layer 13 (13a, 13b), the peripheral surface layer member 14a, and the end surface layer member 14b are firmly bonded to each other at their superposed interfaces to form a strong and robust bonding state required for a rolling roll. It

After the HIP treatment is completed and the canning material is removed by machining, heat treatment for refining is performed. The heat pattern of the heat treatment is appropriately set according to the combination of material types of the respective members of the composite laminate. For example, as shown in FIG. 1, FIG. 2, FIG. 5, and FIG. 6, in the case of a two-member structure of the base material 12 and the high-speed steel-based sintered alloy layer 13 (13a, 13b), the base material 12 is made of ductile cast iron ( In the case of high-hardness ductile cast iron and toughness ductile cast iron), a high-frequency steel-based sintered alloy layer 13 (13a, 13a,
13b only, quenching from about 1100 to 1200 ° C, 5
The secondary hardening heat treatment is performed at 00 to 600 ° C., while the base material 12 is a Cr—Mo alloy steel, the gas quenching method is applied to quench the material from 1100 to 1200 ° C., and further 500 to By performing the secondary hardening heat treatment at 600 ° C., the base material 12 and the sintered alloy layer 13 (13a,
The refining of 13b) can be achieved.

The base material 12 shown in FIG. 3, a high speed steel-based sintered alloy layer 13a and an end surface layer member 14b
In the case of the member structure, when the end surface layer member 14b is nickel glen cast iron and the base material 12 is ductile cast iron (high hardness ductile cast iron, tough ductile cast iron) or Cr-Mo alloy steel, by induction hardening or the like, The tempering treatment can be achieved by quenching only the high speed steel-based sintered alloy layer 13a from about 1100 to 1200 ° C. and then performing a secondary hardening heat treatment at 500 to 600 ° C. Further, in the case of a three-member configuration including the base material 12 shown in FIG. 4, the high-speed steel-based sintered alloy layer 13b, and the peripheral surface layer member 14a, the peripheral surface layer member 14a is adamite cast iron, and the base material 12 Is a ductile cast iron (high hardness ductile cast iron, tough ductile cast iron), only the high speed steel-based sintered alloy layer 13b is quenched by an induction hardening method or the like, and then a secondary hardening heat treatment is carried out. When the material 12 is a Cr-Mo alloy steel, the tempering can be achieved by applying a gas quenching method or the like to perform quenching and then performing a secondary hardening heat treatment.

[0019]

[Effect] The horizontal roll of the present invention is excellent in wear resistance of the end face of the body and chipping resistance of the peripheral corners, and can be stably used in hot rolling of H-shaped steel materials, It contributes to improvement of service life, reduction of roll maintenance, and efficiency of rolling operation.

[Brief description of drawings]

FIG. 1 is an axial partial sectional view showing an example of a laminated composite structure of a horizontal roll of the present invention.

FIG. 2 is an axial partial sectional view showing an example of a laminated composite structure of a horizontal roll of the present invention.

FIG. 3 is a partial axial sectional view showing an example of a laminated composite structure of a horizontal roll of the present invention.

FIG. 4 is an axial partial cross-sectional view showing an example of a laminated composite structure of a horizontal roll of the present invention.

FIG. 5 is a partial axial sectional view showing an example of a laminated composite structure of a horizontal roll of the present invention.

FIG. 6 is a partial axial sectional view showing an example of a laminated composite structure of a horizontal roll of the present invention.

FIG. 7 is an axial sectional view showing another example of the outer shape of the body of the horizontal roll of the present invention.

FIG. 8 is a schematic front view showing hot rolling of H-section steel.

[Explanation of symbols]

10: Horizontal roll, 12: Base material, 13 (13a, 13
b): high-speed steel-based sintered alloy layer, 14a: ductile toughness member, 1
4b: wear resistant member, 20: vertical roll, w: rolled material,
a: web, b: flange.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Katayama 64 Nishimukojima-cho, Amagasaki City, Hyogo Prefecture Kubota Co., Ltd. Amagasaki Plant

Claims (1)

[Claims] 1. A roll body has a peripheral surface and / or an end surface made of a high-speed steel-based sintered alloy laminated on a base material as a hot isostatic pressing body. H
Horizontal roll for hot rolling of shaped steel.