A special steel heating furnace roller device and its use

Abstract

The present invention relates to a roller device for a special steel heating furnace and its use, comprising a roller and a mandrel located on the same center line; the alloy of the roller is calculated by mass percentage: C0.35-0.55%, Si1-2.5%, Cr27-30%, W4-6%, Mn≤1.5%, P≤0.04%, S≤0.05%, and the remainder is Ni; the mandrel comprises a first mandrel part, a second mandrel part and a third mandrel part, the first mandrel part is located inside the roller, and the mandrel parts are connected by a chamfering structure; the diameter of the water channel in the first mandrel part>the diameter of the water channel in the second mandrel part>the diameter of the water channel in the third mandrel part; the length of the water channel in the first mandrel part<the length of the water channel in the third mandrel part<the length of the water channel in the second mandrel part. By redesigning the roller material and the design inside the mandrel, the problem of iron oxide scale adhering to the roller surface during the special steel heating process is avoided.

Description

Technical Field

[0001] The invention relates to the field of steelmaking, and in particular to a roller table device for a special steel heating furnace and a use thereof. Background Art

[0002] The billet alloy content of special steel heating furnace is high, and the iron oxide scale produced after high temperature heating has high adhesion. When the heating furnace is tapping steel, the iron oxide scale adheres to the surface of the cantilever roller in the furnace. As the iron scale adhesion accumulates, many raised hard spots are formed on the roller surface, and pits and scratches appear on the lower surface of the billet when the roller transports the billet.

[0003] At present, the steel bar rolling production line adopts a walking-type double-heat storage heating furnace, and the heating furnace is loaded and unloaded by the side-in and side-out method of the roller table inside the furnace.

[0004] For example, CN112692054A discloses a bar steel rolling and cutting process that can reduce the cost of raw materials, including the following steps: prepare the steel bar to be cut, heat it in a heating furnace, and then use the rough rolling unit for processing; then enter the medium rolling unit after passing through the 1# flying shear head, and obtain a preset rectangle through two horizontal and vertical rolling passes, and then enter the pre-cutting and cutting passes immediately, and then the several groups of billets separated by the cutting are respectively entered into the controlled rolling water tank and passed through the water pipe for temperature control; then pass through the 2# flying shear head, and the multiple groups of steel materials after cutting are simultaneously entered into the finishing rolling unit for rolling 2-4 passes to form finished products. This scheme can most effectively avoid the adverse effects of controlled rolling and cooling of low-temperature steel on the cutting pass, while meeting the requirement that the steel rolling capacity is not affected and can also achieve controlled rolling and controlled cooling to achieve the goal of refining the internal structure grain of the finished product, without using a high-alloyed billet to improve the physical properties, and truly achieve the ultimate goal of reducing the alloy ratio and reducing the cost of raw materials.

[0005] CN102889786A discloses a cantilever roller, comprising at least one cantilever roller unit with water inner cooling, the unit comprising a roller filled with refractory fiber installed in the cantilever roller, the roller is installed on a high-performance alloy steel roller shaft that is water-cooled and air-cooled or wrapped with refractory fiber, the roller shaft is installed on the cantilever roller seat with a high-temperature rolling bearing, the roller seat is equipped with a reducer with a variable frequency motor, the gap between the rotating roller shaft and the fixed insulation sleeve is passed through cold air to block the heat flow from overflowing, or the roller shaft is wrapped with refractory fiber, the insulation sleeve is sleeved in a special prefabricated part, the gap between them is filled with refractory cotton, and is sealed with a pressure plate. The prefabricated part is built in the furnace wall, the end of the roller shaft is connected to the rotary joint, and the roller seat is slidably fixed on the base. The roller shaft cantilever length in this scheme is greatly shortened, the operating conditions are improved, the operating reliability is improved, the equipment structure is simple, and the maintenance is convenient and fast, which is suitable for both new construction and technical transformation of old furnaces.

[0006] However, due to the production process of special steel, the temperature of the billet when entering the furnace is strictly required to avoid internal structural defects of the billet caused by overheating. After the billet in the furnace is fully preheated, it enters the rapid heating stage and the soaking stage, and the furnace temperature reaches between 1150-1250℃. Si, Ni, and Cr in special steel have strong adhesion at high temperatures. As the heating furnace continuously discharges steel, the iron oxide scale on the lower surface of the billet continuously adheres to the surface of the roller in the furnace, resulting in the formation of many protruding hard spots on the surface of the roller, which damages the lower surface of the high-temperature billet discharged from the furnace. Summary of the invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a special steel heating furnace roller device and its use to solve the problem of iron oxide scale adhesion on the lower surface of the steel billet when the heating furnace continuously discharges steel during the special steel preparation process.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a special steel heating furnace roller device, the special steel heating furnace roller device comprising a roller and a mandrel located on the same center line;

[0010] The alloy of the roller is calculated by mass percentage: C 0.35-0.55%, Si 1-2.5%, Cr 27-30%, W 4-6%, Mn≤1.5%, P≤0.04%, S≤0.05%, and the balance is Ni;

[0011] The mandrel comprises a first mandrel portion, a second mandrel portion and a third mandrel portion which are connected in sequence;

[0012] The first mandrel portion is located inside the roller table;

[0013] The first mandrel portion, the second mandrel portion and the third mandrel portion are connected by a chamfered structure;

[0014] The diameter of the water channel in the first core shaft portion>the diameter of the water channel in the second core shaft portion>the diameter of the water channel in the third core shaft portion;

[0015] The length of the water channel in the first core shaft portion is less than the length of the water channel in the third core shaft portion and less than the length of the water channel in the second core shaft portion.

[0016] The roller device of the special steel heating furnace provided by the present invention avoids the adhesion of iron oxide scale to the roller surface during the heating process of special steel, thereby preventing pits and scratches on the lower surface of the steel billet, and causing folding defects on the surface of the bar, through the redesign of the roller material and the design inside the mandrel. This is because the billet alloy content of the special steel heating furnace is relatively high, and the iron oxide scale produced after high-temperature heating has high adhesion. When the heating furnace is tapping steel, the iron oxide scale adheres to the surface of the cantilever roller in the furnace. With the accumulation of the amount of iron scale adhesion, many raised hard spots are formed on the roller surface, and pits and scratches appear on the lower surface of the steel billet when the roller transports the steel billet.

[0017] In the present invention, the specific length of the waterway can be selected based on the limiting relationship and actual needs.

[0018] In the present invention, the steel used for the roller can be smelted by the alloy smelting method in the art, such as melting, refining and pouring the proportioned raw materials, wherein the order of adding the raw materials in the smelting is arranged according to the melting point of the metal.

[0019] In the present invention, the special steel heating furnace roller device is also equipped with a driving device.

[0020] In the present invention, the water channel in the core shaft includes a water inlet and a water outlet. A pump is also configured to realize the circulation of the cooling medium. The cooling medium can be water, oil or other liquid cooling medium commonly used in the art.

[0021] In the present invention, the special steel can be high-quality carbon steel, alloy steel, steel ball steel, bearing steel, non-quenched and tempered steel, tube steel and spring steel, etc. The corresponding steel grades can be Q345 series, 10#-55#, 20Mn-45Mn, 20Cr, 40Cr, 20CrMo-42CrMo, 20CrMnTiH (gear steel), 35MnBM, 40MnBH (shaft), 55SiMnMo, B7, 40CrMn Mo (drilling tools), S20Cr, S45Cr, SCM440 (export materials), 40Mn2, 45Mn2, 27SiMn, 20CrMnMo, 20CrNiMo (8620), 8620H, 60Mn, 65Mn, B2-B6, GCr15, F45MnVS, 37Mn5, 28Mn2V (oil well pipes), 12Cr1MoVG (boiler pipes), 60Si2MnA, etc.

[0022] In the present invention, the C content in the alloy for hot furnace roller is 0.35-0.55% by mass, for example, it can be 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.4%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5%, 0.51%, 0.52%, 0.53%, 0.54% or 0.55%, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0023] In the present invention, the mass percentage of Si in the alloy for hot furnace roller is 1-2.5%, for example, it can be 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4% or 2.5%, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0024] In the present invention, the mass percentage of Cr in the alloy for hot furnace roller is 27-30%, for example, it can be 27%, 27.2%, 27.4%, 27.6%, 27.8%, 28%, 28.2%, 28.4%, 28.6%, 28.8%, 29%, 29.2%, 29.4%, 29.6%, 29.8% or 30%, but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0025] In the present invention, the W content in the alloy for hot furnace roller is 4-6% by mass, for example, it can be 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9% or 6%, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0026] In the present invention, the Mn content in the alloy for hot furnace roller is ≤1.5% by mass percentage, for example, it can be 1.5%, 1.4%, 1.3%, 1.2%, 1.1%, 1%, 0.99%, 0.98%, 0.97%, 0.96% or 0.95%, etc., but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0027] In the present invention, the P content in the alloy for hot furnace roller is ≤0.04% by mass percentage, for example, it can be 0.04%, 0.039%, 0.038%, 0.037%, 0.036%, 0.035%, 0.034%, 0.033%, 0.032%, 0.031%, 0.03%, 0.029%, 0.028%, 0.027%, 0.026% or 0.025%, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0028] In the present invention, the S content in the alloy for hot furnace roller is ≤0.05% by mass percentage, for example, it can be 0.05%, 0.048%, 0.046%, 0.044%, 0.042%, 0.04%, 0.038%, 0.036%, 0.034%, 0.032%, 0.03%, 0.028%, 0.026%, 0.024%, 0.022%, 0.02%, 0.018%, 0.016% or 0.015%, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0029] As a preferred technical solution of the present invention, the alloy for the hot furnace roller has the following mass percentage contents: C 0.42-0.55%, Si 1-1.62%, Cr 27-28%, W 4-4.32%, Mn 0.96-1%, P≤0.025%, S≤0.015%, and the balance is Ni.

[0030] As a preferred technical solution of the present invention, the width of the roller is 380-385mm, for example, it can be 380mm, 380.2mm, 380.4mm, 380.6mm, 380.8mm, 381mm, 381.2mm, 381.4mm, 381.6mm, 381.8mm, 382mm, 382.2mm, 382.4mm, 382.6mm, 382.8mm, 383mm, 383.2mm, 383.4mm, 383.6mm, 383.8mm, 384mm, 384.2mm, 384.4mm, 384.6mm, 384.8mm or 385mm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0031] As a preferred technical solution of the present invention, the diameter of the water channel in the first core shaft portion is 95-98mm, for example, it can be 95mm, 95.2mm, 95.4mm, 95.6mm, 95.8mm, 96mm, 96.2mm, 96.4mm, 96.6mm, 96.8mm, 97mm, 97.2mm, 97.4mm, 97.6mm, 97.8mm or 98mm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0032] As a preferred technical solution of the present invention, the diameter of the water channel in the second core shaft portion is 70-72mm, for example, it can be 70mm, 70.1mm, 70.2mm, 70.3mm, 70.4mm, 70.5mm, 70.6mm, 70.7mm, 70.8mm, 70.9mm, 71mm, 71.1mm, 71.2mm, 71.3mm, 71.4mm, 71.5mm, 71.6mm, 71.7mm, 71.8mm, 71.9mm or 72mm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0033] As a preferred technical solution of the present invention, the diameter of the water channel in the third core shaft portion is 38-40mm, for example, it can be 38mm, 38.1mm, 38.2mm, 38.3mm, 38.4mm, 38.5mm, 38.6mm, 38.7mm, 38.8mm, 38.9mm, 39mm, 39.1mm, 39.2mm, 39.3mm, 39.4mm, 39.5mm, 39.6mm, 39.7mm, 39.8mm, 39.9mm or 40mm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0034] As a preferred technical solution of the present invention, the width of the chamfered structure along the center line of the core shaft is 12-14mm, for example, it can be 12mm, 12.1mm, 12.2mm, 12.3mm, 12.4mm, 12.5mm, 12.6mm, 12.7mm, 12.8mm, 12.9mm, 13mm, 13.1mm, 13.2mm, 13.3mm, 13.4mm, 13.5mm, 13.6mm, 13.7mm, 13.8mm, 13.9mm or 14mm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0035] Preferably, the angle of the chamfered structure is 40-45°, for example, 40°, 41°, 42°, 43°, 44° or 45°, but is not limited to the listed values, and other values ​​not listed in the range are also applicable. That is, in the present invention, adjacent mandrel parts are connected by a gradually reduced structure, such as the chamfered structure used in the present invention.

[0036] As a preferred technical solution of the present invention, the wall thickness of the core shaft in the contact portion between the roller and the core shaft is 41-42mm, for example, it can be 41mm, 41.1mm, 41.2mm, 41.3mm, 41.4mm, 41.5mm, 41.6mm, 41.7mm, 41.8mm, 41.9mm or 42mm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0037] As a preferred technical solution of the present invention, the roller table and the mandrel are fixedly connected by a key or a pin.

[0038] In a second aspect, the present invention provides a use of the special steel heating furnace roller device as described in the first aspect, and the use includes assembling a special steel heating furnace using the special steel heating furnace roller device.

[0039] Preferably, at least 7 special steel heating furnace roller devices are configured in the special steel heating furnace.

[0040] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0041] The special steel heating furnace roller device provided by the present invention adopts a specially designed alloy material and a core shaft with specific parameters to prevent the iron oxide scale generated on the surface of the special steel from adhering to the roller surface during the heating process of the special steel in the heating furnace, thereby ensuring that no raised hard spots are generated on the roller surface during the continuous operation of the roller, and ensuring that the lower surface of the high-temperature special steel billet discharged from the furnace has good quality without surface defects such as pits and scratches. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the special steel heating furnace roller device provided in Example 1 of the present invention.

[0043] In the figure: 1-roller, 2.1-first mandrel part, 2.2-second mandrel part, 2.3-second mandrel part, 3-key.

[0044] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0045] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0046] Example 1

[0047] This embodiment provides a special steel heating furnace roller device, such as Figure 1 As shown, the special steel heating furnace roller device comprises a roller 1 and a mandrel located on the same center line;

[0048] The alloy of the roller 1 is calculated by mass percentage: C 0.42%, Si 1.62%, Cr 27.95%, W4.32%, Mn 0.96%, P 0.025%, S 0.015%, and the balance is Ni;

[0049] The mandrel comprises a first mandrel portion 2.1, a second mandrel portion 2.2 and a third mandrel portion 2.3 which are connected in sequence;

[0050] The first core shaft portion 2.1 is located inside the roller 1; the width of the roller 1 is 385 mm; the width of the roller 1 is reduced from 400 mm in the prior art to 385 mm, which meets the requirements of use while reducing the heated area, which is beneficial to lowering the return temperature of the cooling water, that is, the roller 1 and the core shaft are designed with the same centerline.

[0051] The first core shaft portion 2.1, the second core shaft portion 2.2 and the third core shaft portion 2.3 are connected by a chamfered structure; the width of the chamfered structure along the center line of the core shaft is 12 mm; the angle of the chamfered structure is 45°, and the position where the internal diameter of the core shaft water channel changes is chamfered to reduce water resistance and avoid vaporization of cooling water.

[0052] The diameter of the water channel in the first core shaft portion 2.1 is greater than the diameter of the water channel in the second core shaft portion 2.2 and greater than the diameter of the water channel in the third core shaft portion 2.3; the diameter of the water channel in the first core shaft portion 2.1 is 95 mm, the diameter of the water channel in the second core shaft portion 2.2 is 70 mm, and the diameter of the water channel in the third core shaft portion 2.3 is 38 mm.

[0053] The length of the water channel inside the first core shaft portion 2.1 is less than the length of the water channel inside the third core shaft portion 2.3, which is less than the length of the water channel inside the second core shaft portion 2.2. Specifically, in this embodiment, the length of the water channel inside the first core shaft portion 2.1 is 385 mm, the length of the water channel inside the second core shaft portion 2.2 is 1425 mm, and the length of the water channel inside the third core shaft portion 2.3 is 526 mm.

[0054] The wall thickness of the mandrel in the contact portion between the roller 1 and the mandrel is 41.5 mm. The roller 1 and the mandrel are fixedly connected by a key or a pin. Specifically, in this embodiment, the roller 1 and the second mandrel portion 2.2 of the mandrel are fixed by a key 3.

[0055] In this embodiment, by adjusting the inner diameter of the roller 1 and the wall thickness of the roller 1 and the mandrel equipped part, the heat exchange speed of the roller is increased, so as to achieve the purpose of accelerating the cooling of the roller.

[0056] Application Example 1

[0057] This application example uses the special steel heating furnace roller device provided in Example 1 in the heating furnace, and 7 rollers are configured.

[0058] The specific heating process is as follows: For the specific high-temperature special steel (20CrMnTiH (gear steel)), it is conveyed through a roller table and continuously passes through seven special steel heating furnace roller devices arranged side by side. That is, at this time, the travel direction of the special steel is perpendicular to the center line of the core shaft, thereby achieving the heating of the special steel.

[0059] During the continuous steel-making process, there are no surface problems such as scratches or dents on the lower surface of the high-temperature steel billet, and there are no raised hard spots formed by the accumulation of iron oxide scale on the roller surface.

[0060] It is stated that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0061] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0062] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0063] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A roller table device for a special steel heating furnace, characterized in that: The special steel heating furnace roller device comprises a roller and a mandrel located on the same center line; The alloy of the roller is calculated by mass percentage as follows: C 0.35-0.55%, Si 1-2.5%, Cr 27-30%, W 4-6%, Mn≤1.5%, P≤0.04%, S≤0.05%, and the balance is Ni; The mandrel comprises a first mandrel portion, a second mandrel portion and a third mandrel portion which are connected in sequence; The first mandrel portion is located inside the roller table; The first mandrel portion, the second mandrel portion and the third mandrel portion are connected by a chamfered structure; The diameter of the water channel in the first core shaft portion>the diameter of the water channel in the second core shaft portion>the diameter of the water channel in the third core shaft portion; The length of the water channel in the first core shaft portion is less than the length of the water channel in the third core shaft portion and less than the length of the water channel in the second core shaft portion.

2. The roller table device for a special steel heating furnace according to claim 1, characterized in that: The alloy of the roller is calculated by mass percentage as follows: C 0.42-0.55%, Si 1-1.62%, Cr 27-28%, W 4-4.32%, Mn 0.96-1%, P≤0.025%, S≤0.015%, and the balance is Ni.

3. The roller table device for special steel heating furnace according to claim 1, characterized in that: The width of the roller is 380-385 mm.

4. The roller table device for a special steel heating furnace as claimed in claim 1, characterized in that: The diameter of the water channel in the first core shaft portion is 95-98 mm.

5. The roller table device for special steel heating furnace according to claim 1, characterized in that: The diameter of the water channel in the second core shaft portion is 70-72 mm.

6. The roller table device for special steel heating furnace according to claim 1, characterized in that: The diameter of the water channel in the third core shaft portion is 38-40 mm.

7. The roller table device for special steel heating furnace according to claim 1, characterized in that: The width of the chamfered structure along the center line of the mandrel is 12-14 mm.

8. The roller table device for a special steel heating furnace as claimed in claim 1, characterized in that: The angle of the chamfered structure is 40-45°.

9. The roller table device for a special steel heating furnace as claimed in claim 1, characterized in that: The wall thickness of the mandrel in the contact area between the roller and the mandrel is 41-42 mm.

10. The roller table device for a special steel heating furnace as claimed in claim 1, characterized in that: The roller table and the mandrel are fixedly connected via a key or a pin.

11. A use of a roller table device for a special steel heating furnace as claimed in any one of claims 1 to 10, characterized in that: The use includes assembling a special steel heating furnace using the special steel heating furnace roller device.

12. The use according to claim 11, characterized in that At least 7 special steel heating furnace roller devices are configured in the special steel heating furnace.

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