JPH059703U - Conveyor roll for heating furnace - Google Patents

Abstract

(57) [Summary] [Purpose] To extend the life of the transfer rolls for heating furnaces. [Structure] In order to convey the object to be heated in the heating furnace, a plurality of grooves are formed on the surface of the body of the roll in a circumferential direction,
A heating-furnace-conveying roll having a groove portion filled with a refractory material, in which the respective dimensions of the groove portion satisfy the expressions (1) to (4). 1/45 ≦ t / d ≦ 1/10 (1) 1/4 ≦ l _m / l _h ≦ 1 (2) 1/5 ≦ r / l _m ≦ 1/2 (...) _{3) 1/30 ≦ l m} / d ≦ 1/10 ......... (4) However, d is the roll diameter, t is the groove depth, l _m is the groove width,
r is the bottom corner radius of the groove, and l _h is the width of the roll surface between the grooves.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention conveys the slab cast by the continuous casting machine to the rolling line without reheating and directly rolls it. When directly rolling, the short side (both sides) of the slab provided in the conveying line is The present invention relates to a carrier roll for carrying a slab or the like in a heating furnace such as a heating device for additional heating.

[0002]

[Prior Art]

 Since the transfer rolls in the heating furnace are also used to transfer materials exceeding 1000 ° C. in an atmosphere exceeding 1000 ° C., most of the damage to the transfer rolls is due to thermal stress. The heat transferred to the transfer rolls comes from the atmosphere in the heating furnace, from the material being transferred, from the flame of the burner, and from the transfer rolls to maintain the strength of the transfer rolls. The heat is transferred to the cooling water supplied to the inside of the roll. The heat transfer method is by radiation and convection from the atmosphere, contact and radiation from the material, radiation and convection from the flame, and convection to the cooling water.

Heat is thus transferred from various heat sources to the transfer rolls in the heating furnace, but since it is the rolls in the heating furnace, the heat removal from the material to be heated must be small. This is inconsistent with the cooling inside the roll to maintain the roll strength.

As a roll for transferring a high temperature object, there is a roll disclosed in Japanese Utility Model Laid-Open No. 56-175157 shown in FIG. This roll has a heat insulating material 22 attached to the roll surface of the roll main body 20 so as to cover the circumferentially formed recess 21. This reduces thermal stress on the roll, thereby causing cracks and breakage of the roll. Accidents can be reduced.

[0005]

[Problems to be solved by the device]

 However, when the above-mentioned conventional roll for transporting a high-temperature object is used as a transport roll in a heating furnace, there are the following problems. That is, in the uneven structure of the roll surface, the presence of the recessed portion suppresses the contact area with the high temperature object, reduces the thermal stress generated in the roll, and releases the thermal stress of the roll surface layer at the raised portion, thereby generating cracks. However, the transfer roll in the heating furnace has a remarkably high level of thermal stress, so it cannot be put to practical use unless the dimensions of the concave and convex parts are regulated within a certain fixed value. was there.

An object of the present invention is to solve the above-mentioned problems of the prior art and provide a heating furnace carrying roll that can be used in a heating furnace.

[0007]

[Means for Solving the Problems]

 In order to convey an object to be heated in a heating furnace, a heating furnace carrying roll according to the present invention is provided with a plurality of circumferentially circumferential groove portions on the body surface of the roll, and the heating furnace is filled with a refractory material. In the carrier roll for use, the respective dimensions of the groove portion satisfy the expressions (1) to (4).

1/45 ≦ t / d ≦ 1/10 (1) 1/4 ≦ l _m / l _h ≦ 1 (2) 1/5 ≦ r / l _m ≦ 1/2 (3) 1/30 ≦ l _m / d ≦ 1/10 (4) However, d: roll diameter (mm) t: groove depth (mm) 1 _m : groove width (mm) r: Groove bottom corner radius (mm) l _h : Width of roll surface between grooves

[0009]

In order to convey the object to be heated in the heating furnace, the conveying roll for the heating furnace according to the present invention is provided with a plurality of circumferential groove portions on the surface of the roll body, and the groove portions are filled with the refractory material. In the heating furnace transfer roll described above, the dimensions of the groove portions satisfy the expressions (1) to (4).

1/45 ≦ t / d ≦ 1/10 (1) 1/4 ≦ l _m / l _h ≦ 1 (2) 1/5 ≦ r / l _m ≦ 1/2 (3) 1/30 ≦ l _m / d ≦ 1/10 (4) However, d: roll diameter (mm) t: groove depth (mm) 1 _m : groove width (mm) r: Groove bottom corner radius (mm) l _h : Width of roll surface between grooves

The reason is as follows. (1) Reason that t / d is 1/45 or more and 1/10 or less The upper limit and the lower limit are limited by the elastic thermal stress calculation result, and the upper limit is also limited in consideration of the processing cost.

(2) Reason why l _m / l _h is 1/4 or more and 1 or less The lower limit is the limit at which the thermal stress releasing effect at the convex portion can be expected, and the upper limit is the crush resistance and abrasion resistance of the convex portion. , Dropout resistant.

(3) Reason that r / l _m is 1/5 or more and 1/2 or less The lower limit is the limit at which stress concentrates on the bottom r of the recess and cracking does not occur, and the upper limit is the stress at the bottom r of the recess. The limit of openness.

(4) Reason why l _m / d is 1/30 or more and 1/10 or less The lower limit is the limit of stress releasability at the convex portion, and the upper limit is the processing cost.

[0015]

【Example】

 A heating furnace transfer roll according to an embodiment of the present invention will be described with reference to FIG. In order to convey an object to be heated in a heating furnace, a heating furnace carrying roll according to an embodiment of the present invention is provided with a plurality of circumferentially circumferential groove portions 2 on the body surface 1a of the roll 1, and the groove portions 2 A plurality of Y studs 3 are welded and attached in the circumferential direction, and the refractory material 4 is filled.

Then, the depth (t) and the width (l _m ) of the groove portion 2 are regulated as shown in the following formulas (1) and (4) in relation to the diameter (d) of the roll 1, and The relationship between the width (1 _m ) of the roll 2 and the width (1 _h ) of the body surface 1a of the roll 1 between the adjacent groove portions 2 is regulated by the formula (2). Further, the relationship between the width (l _m ) of the concave portion 2 and the corner radius (r) of the corner 2a at the bottom of the groove portion 2 shown in FIG. 2 is regulated by the equation (3).

1/45 ≦ t / d ≦ 1/10 (1) 1/4 ≦ l _m / l _h ≦ 1 (2) 1/5 ≦ r / l _m ≦ 1/2 ...... (3) 1/30 ≤ l _m / d ≤ 1/10 ... (4)

Table 1 shows the range of the above-mentioned respective dimensions when the diameter (d) of the roll 1 is 450 mm.

[0019]

[Table 1]

From the range shown in Table 1, a roll having a diameter of 450 mm has a groove width of 20 mm, a roll surface width between adjacent groove portions of 40 mm, a groove depth of 20 mm, and a corner radius of 5 mm at the bottom of the groove. Processed as follows. Then, a plurality of Y studs were welded to the bottom of the groove along the circumferential direction, and the groove was filled with a refractory material. When this roll was used as a transport roll in a heating furnace, the crack growth rate from the roll surface of the conventional flat roll was 1.63 mm / month, but it was significantly reduced to 1.00 mm / month. Therefore, the effect of the present invention was proved to be great.

[0021]

[Effect of the device]

 This device has the following effects. (1) The life of the roll is extended because the growth rate of cracks on the roll surface is significantly reduced. (2) Since the heat removal from the object to be heated is reduced, the heating efficiency is improved and the uneven temperature distribution in the width direction of the object to be heated is eliminated, and the quality and yield of the rolled product are improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a transfer roll for a heating furnace according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a corner of a groove bottom portion of a heating furnace carrying roll according to an embodiment of the present invention.

FIG. 3 is a sectional view of a conventional heating furnace transfer roll.

[Explanation of symbols]

 1 Roll 2 Groove 3 Y Stud 4 Refractory

Claims (1)

[Claims for utility model registration] [Claim 1] In order to convey an object to be heated in a heating furnace,
In the heating furnace carrying roll in which a plurality of circumferential groove portions are provided on the surface of the body of the roll and the groove portions are filled with a refractory material, it is required that each dimension of the groove portions satisfies the expressions (1) to (4). Characteristic heating furnace transfer roll. 1/45 ≦ t / d ≦ 1/10 (1) 1/4 ≦ l _m / l _h ≦ 1 (2) 1/5 ≦ r / l _m ≦ 1/2 (...) 3) 1/30 ≦ l _m / d ≦ 1/10 (4) where d: roll diameter (mm) t: groove depth (mm) l _m : groove width (mm) r: groove bottom corner Radius (mm) l _h : Width of roll surface between grooves