Hot straightening work roll and preparation method thereof

Abstract

The present invention belongs to the technical field of hot straightening work rolls, and in particular relates to hot straightening work rolls and methods for their manufacture. The work roll comprises a cylinder I providing a working area and a second cylinder coaxially disposed at both ends of cylinder I. Cylinder I comprises a roll body, which includes a base layer formed at least partially by overlay welding and a hardfacing layer. The present invention utilizes a multi-layered structure for the main body of the roll, such as the roll body. The base layer is made of a tough material, the surface is provided with a high-hardness hardfacing layer, and the inner lining of the roll is made of a tough material, including one or more of carbon steel and 42 chromium-molybdenum. This design achieves excellent impact absorption, is less susceptible to rebound, has strong resistance to impact damage, and exhibits excellent stability, thereby preventing cracking caused by stress generated by temperature differences between the surface and interior of the roll body.

Description

Technical Field

[0001] The invention belongs to the technical field of hot straightening work rolls, and in particular relates to a hot straightening work roll and a preparation method thereof. Background Art

[0002] When water is passed through the interior of the existing hot straightening work roll for water cooling, the surface of the work roll is water-cooled during operation, which can easily cause cracks due to the stress caused by the temperature difference between the surface and the interior. This is mainly because the existing roll is made of high-rigidity and high-hardness alloy steel as a whole. Due to the poor toughness of the material, it is easy to form cracks and damage. In addition, the material thickness at the chamfer of the hot straightening work roll is lower than that at other places, which can also cause cracks at the connection. Summary of the Invention

[0003] In order to solve the problems raised in the above background technology, the present invention provides a hot straightening work roll and a preparation method thereof, which has good toughness and will not cause cracking due to stress generated by the temperature difference between the surface and the interior. The working surface of the roll body is welded with a high-temperature and wear-resistant alloy material by submerged arc cladding, so as to make the hot straightening work roll.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a hot-straightening work roll, comprising a cylinder I providing a working area and a cylinder II coaxially arranged at both ends of the cylinder I, the cylinder I comprising a roll body, the roll body comprising a base layer at least partially formed by surfacing and a hard surface layer (at least one of the base layer and the hard surface layer is entirely or partially formed by surfacing), the composition of the base layer is, by mass percentage: C0.3%, Mo1%, Cr5%, Mn1.5%, Ni1%, and the balance is iron and inevitable impurities; the composition of the hard surface layer is, by mass percentage: C0.7%, Mo5%, Cr8%, Mn3%, W7%, V2%, Ti0.15%, Co1%, Nb0.15%, and the balance is iron and inevitable impurities.

[0005] Preferably, cylinder I includes a cold water channel, a roller lining and a roller body, the outer surface of the roller lining is integrally connected to the roller body, cylinder II includes at least a first cylinder, a second cylinder and a third cylinder, the cold water channel is arranged in the roller lining, the roller lining is made of tough material, the two ends of the roller body are respectively connected to the first cylinder and the second cylinder through the first chamfered plate and the second chamfered plate, the ends of the first cylinder and the second cylinder away from each other are respectively connected to the third cylinder and the fourth cylinder through the third chamfered plate and the fourth chamfered plate, the third cylinder is provided with an external thread, the third cylinder is provided with a spline, and the third cylinder is connected to the fifth cylinder through the fifth chamfered plate.

[0006] Preferably, the material of the roller lining may be composed of one or more of carbon steel and 42 chromium molybdenum.

[0007] Preferably, the inner wall materials of the first cylinder, the second cylinder, the third cylinder, the fourth cylinder, the fifth cylinder, the first chamfered plate, the second chamfered plate, the third chamfered plate, the fourth chamfered plate and the fifth chamfered plate are all made of tough materials.

[0008] Preferably, the splines are made by a cold forming process.

[0009] Preferably, the first chamfered plate, the second chamfered plate, the third chamfered plate, the fourth chamfered plate and the fifth chamfered plate are all hollow plates.

[0010] Preferably, the first cylinder, the second cylinder, the third cylinder, the fourth cylinder, the fifth cylinder, the first chamfered plate, the second chamfered plate, the third chamfered plate, the fourth chamfered plate and the fifth chamfered plate are on the same horizontal line as the center of the cold water channel.

[0011] Preferably, the first chamfered plate, the second chamfered plate, the third chamfered plate, the fourth chamfered plate and the fifth chamfered plate are hollow plates with a curvature.

[0012] Preferably, the preparation method of the hot straightening work roll includes the hot straightening work roll as described above, and the preparation method includes a base material manufacturing method and a composite manufacturing method:

[0013] (1) The method for manufacturing the parent material is:

[0014] 42 chromium-molybdenum material preparation;

[0015] Heating, raising the temperature to 1200℃ in stages, keeping it warm for at least 3 hours, and then taking it out of the furnace for forging;

[0016] Forging, forging ratio ≥ 3;

[0017] Normalizing, temperature range is 860-880℃, keep warm for at least 5 hours;

[0018] Inspection, rough turning, and flaw detection;

[0019] Tempering, temperature range: 860℃±10℃, and keep warm for at least 5 hours;

[0020] Flaw detection, testing, and inspection;

[0021] (2) Composite manufacturing method:

[0022] Preparation of parent material;

[0023] Preheating temperature range: 100℃±3℃, keep warm for at least 4 hours;

[0024] Submerged arc cladding is performed on the wood surface to form at least a base layer and a hard surface layer;

[0025] Heat treatment, temperature range: 850℃±10℃, at least 15 days;

[0026] reprocessing;

[0027] Finished product inspection.

[0028] Further preferably, the preparation method of the hot-straightening work roll includes a base material manufacturing method and a composite manufacturing method:

[0029] (1) The method for manufacturing the parent material is:

[0030] 42 chromium-molybdenum continuous casting billet;

[0031] Blank inspection: Use a SPECTRO spectrometer to inspect the appearance of the blank;

[0032] Cutting, using a horizontal sawing machine;

[0033] Heating: natural gas heating furnace, heating up to 1200℃ in stages, keeping warm for 3 hours, then taking out of furnace for forging;

[0034] Forging, forging ratio ≥ 3, 4 tons electro-hydraulic hammer;

[0035] Normalizing: Use an electric furnace with a temperature range of 860-880℃ and keep warm for 5 hours;

[0036] Inspection, using a portable flaw detector for flaw detection;

[0037] Rough turning, horizontal lathe;

[0038] For flaw detection, a portable flaw detector is used;

[0039] For tempering, use a 300kW electric heating furnace at a temperature of 860°C ± 10°C and keep warm for 5 hours;

[0040] Flaw detection: use portable flaw detector for flaw detection;

[0041] Mechanical properties test, using tensile and impact testing machines for mechanical properties testing;

[0042] test;

[0043] (2) Composite manufacturing method:

[0044] Parent material inspection;

[0045] Rough turning of parent metal;

[0046] Drilling deep holes in parent materials;

[0047] Preheating, temperature range: 100℃±3℃, keep warm for 4 hours;

[0048] For submerged arc cladding, use base wire NE8122 and hardfacing wire NE8556 at a welding speed of 500±20mm / min. The base thickness on one side is 4mm, the effective hardfacing layer is over 14mm, and a machining allowance of 4mm is ensured on one side.

[0049] Heat treatment, temperature range: 850℃±10℃, 15 days;

[0050] Lathe rough machining;

[0051] Inspection: Check the size, hardness HRC54-58 and color after rough processing, and use ultrasonic testing for flaw detection, etc.

[0052] Lathe finishing;

[0053] Milling splines are processed by cold forming process;

[0054] Grinding;

[0055] Finished product inspection: the finished product's size, hardness HRC54-58 and color are inspected, and ultrasonic flaw detection is used.

[0056] Furthermore, one end of the roller body in the hot straightening working roller is connected to the first chamfered plate by surfacing welding, the other end of the first chamfered plate is connected to the first cylinder by surfacing welding, the other end of the cylinder is connected to the second chamfered plate, the second chamfered plate is connected to the second cylinder, the second cylinder is connected to the fourth chamfered plate, and the fourth chamfered plate is connected to the fourth cylinder by surfacing welding; the third cylinder is connected to the third chamfered plate, and the first cylinder is connected to the third chamfered plate by surfacing welding.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] 1. The present invention provides a roller lining, which is made of a tough material, including one or more of carbon steel and 42 chrome-molybdenum. For example, chrome-molybdenum steel has good impact absorption performance, and there will be a rebound feeling when a hammer hits it, and violent damage cannot be carried out, thereby avoiding the phenomenon of cracking caused by the stress generated by the temperature difference between the surface and the interior of the roller body.

[0059] 2. The present invention uses surfacing welding to connect, and the strengthening function of surfacing welding can be used to strengthen the connection between the chamfered plate and the cylinder, and the roller body and the chamfered plate, so as to achieve wear resistance, heat resistance, corrosion resistance, etc. of the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0061] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0062] Figure 2 This is a schematic structural diagram of the roller lining of the present invention;

[0063] In the figure: 1. roller body; 2. first cylinder; 3. first chamfered plate; 4. third chamfered plate; 5. third cylinder; 6. external thread; 7. spline; 8. fifth chamfered plate; 9. fifth cylinder; 10. second chamfered plate; 11. second cylinder; 12. fourth cylinder; 13. fourth chamfered plate; 14. roller lining; 15. cold water channel. DETAILED DESCRIPTION

[0064] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0065] The main improvements of the present invention are: Figure 1 The roll body structure of the hot straightening work roll shown in the figure is mainly divided into two parts, cylinder I and cylinder II, which are connected by shrinkage. The two parts are integrated by shrinkage.

[0066] Example 1

[0067] See also Figure 1-2 The present invention provides the following technical solutions: a hot straightening work roll, comprising a cold water channel 15, a roller lining 14 and a roller body 1, wherein the outer surface of the roller lining 14 is integrally connected to the roller body 1, the cold water channel 15 is arranged in the roller lining 14, the roller lining 14 is made of a tough material, and the material of the roller lining 14 can be composed of one or more of carbon steel and 42 chromium molybdenum, etc., the two ends of the roller body 1 are respectively connected to the first cylinder 2 and the second cylinder 11 through the first chamfer plate 3 and the second chamfer plate 10, and the ends of the first cylinder 2 and the second cylinder 11 away from each other are respectively connected through the third chamfer plate 4 and the fourth chamfer plate 13 A third cylinder 5 and a fourth cylinder 12 are connected, the third cylinder 5 is provided with an external thread 6, the third cylinder 5 is provided with a spline 7, the spline 7 is made by a cold forming process, the third cylinder 5 is connected to the fifth cylinder 9 through a fifth chamfered plate 8, and the roller lining 14 is provided. The roller lining 14 is made of tough material, including one or more of carbon steel and 42 chrome molybdenum, such as chrome-molybdenum steel, which has good impact absorption performance. There will be a rebound feeling when a hammer hits it, and violent destruction cannot be carried out, thereby avoiding the phenomenon of cracking caused by the stress generated by the temperature difference between the surface and the interior of the roller body 1.

[0068] Specifically, the inner wall materials of the first cylinder 2, the second cylinder 11, the third cylinder 5, the fourth cylinder 12, the fifth cylinder 9, the first chamfered plate 3, the second chamfered plate 10, the third chamfered plate 4, the fourth chamfered plate 13 and the fifth chamfered plate 8 are all tough materials. The first cylinder 2, the second cylinder 11, the third cylinder 5, the fourth cylinder 12, the fifth cylinder 9, the first chamfered plate 3, the second chamfered plate 10, the third chamfered plate 4, the fourth chamfered plate 13 and the fifth chamfered plate 8 are on the same horizontal line with the center of the cold water channel 15, and are connected by surfacing welding. The strengthening function of surfacing welding can be used to strengthen the connection between the chamfered plate and the cylinder, and the roller body 1 and the chamfered plate, so as to achieve wear resistance, heat resistance, corrosion resistance, etc. of the connection.

[0069] Specifically, the first chamfered plate 3 , the second chamfered plate 10 , the third chamfered plate 4 , the fourth chamfered plate 13 and the fifth chamfered plate 8 are all hollow plates. The provision of the hollow plates facilitates the passage of cold water.

[0070] Specifically, the first chamfered plate 3 , the second chamfered plate 10 , the third chamfered plate 4 , the fourth chamfered plate 13 and the fifth chamfered plate 8 are hollow plates with a curvature.

[0071] The preparation method of the hot straightening work roll includes a base material manufacturing method and a composite manufacturing method:

[0072] (1) The method for manufacturing the parent material is:

[0073] 42 chromium-molybdenum continuous casting billet;

[0074] Blank inspection: Use a SPECTRO spectrometer to inspect the appearance of the blank;

[0075] Cutting, using a horizontal sawing machine;

[0076] Heating: natural gas heating furnace, heating up to 1200℃ in stages, keeping warm for 3 hours, then taking out of furnace for forging;

[0077] Forging, forging ratio ≥ 3, 4 tons electro-hydraulic hammer;

[0078] Normalizing: Use an electric furnace with a temperature range of 860-880℃ and keep warm for 5 hours;

[0079] Inspection, using a portable flaw detector for flaw detection;

[0080] Rough turning, horizontal lathe;

[0081] For flaw detection, a portable flaw detector is used;

[0082] For tempering, use a 300kW electric heating furnace at a temperature of 860°C ± 10°C and keep warm for 5 hours;

[0083] Flaw detection: use portable flaw detector for flaw detection;

[0084] Mechanical properties test, using tensile and impact testing machines for mechanical properties testing;

[0085] test;

[0086] (2) Composite manufacturing method:

[0087] Parent material inspection;

[0088] Rough turning of parent metal;

[0089] Drilling deep holes in parent materials;

[0090] Preheating, temperature range: 100℃±3℃, keep warm for 4 hours;

[0091] For submerged arc cladding, use base wire NE8122 and hardfacing wire NE8556 at a welding speed of 500±20mm / min. The base thickness on one side is 4mm, the effective hardfacing layer is over 14mm, and a machining allowance of 4mm is ensured on one side.

[0092] Among them, the roller body 1 of the cylinder I can include a base layer and a hard surface layer both formed by surfacing welding, and the welding wire forming the base layer has a composition, by mass percentage, of C0.3%, Mo1%, Cr5%, Mn1.5%, Ni1%, and the balance is iron and inevitable impurities; the welding wire forming the hard surface layer has a composition, by mass percentage, of C0.7%, Mo5%, Cr8%, Mn3%, W7%, V2%, Ti0.15%, Co1%, Nb0.15%, and the balance is iron and inevitable impurities.

[0093] One end of the roller body 1 is connected to the first chamfered plate 3 by surfacing welding, the other end of the first chamfered plate 3 is connected to the first cylinder 2 by surfacing welding, the other end of the cylinder is connected to the second chamfered plate 10, the second chamfered plate 10 is connected to the second cylinder 11, the second cylinder 11 is connected to the fourth chamfered plate 13, and the fourth chamfered plate 13 is connected to the fourth cylinder 12 by surfacing welding;

[0094] The third cylinder 5 and the third chamfered plate 4 obtained in step 2, as well as the first cylinder 2 and the third chamfered plate 4, are connected by surfacing welding;

[0095] Heat treatment, temperature range: 850℃±10℃, 15 days;

[0096] Lathe rough machining;

[0097] Inspection: Check the size, hardness HRC54-58 and color after rough processing, and use ultrasonic testing for flaw detection, etc.

[0098] Lathe finishing;

[0099] Milling splines are processed using cold forming technology;

[0100] Grinding;

[0101] Finished product inspection: the finished product's size, hardness HRC54-58 and color are inspected, and ultrasonic flaw detection is used.

[0102] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. The hot straightening work roll comprises a cylinder I providing a working area and a cylinder II coaxially arranged at both ends of the cylinder I, characterized in that: The cylinder body I comprises a roller body, and the roller body comprises a base layer and a hard surface layer formed by at least partial surfacing. The composition of the primer layer is, by mass percentage: C 0.3%, Mo 1%, Cr 5%, Mn 1.5%, Ni 1%, and the balance is iron and unavoidable impurities; The composition of the hard facing layer is, in percentage by mass: C0.7%, Mo5%, Cr8%, Mn3%, W7%, V2%, Ti0.15%, Co1%, Nb0.15%, and the balance is iron and unavoidable impurities; The cylinder I comprises a cold water channel (15), a roller lining (14) and a roller body (1); the cylinder II comprises at least a first cylinder (2), a second cylinder (11) and a third cylinder (5); the outer surface of the roller lining (14) is integrally connected to the roller body (1); the cold water channel (15) is arranged in the roller lining (14); the roller lining (14) is made of a tough material; the two ends of the roller body (1) are connected to the first cylinder (2) and the second cylinder (11) respectively through a first chamfered plate (3) and a second chamfered plate (10); the ends of the first cylinder (2) and the second cylinder (11) away from each other are connected to the third cylinder (2) and the fourth chamfered plate (13) respectively. The third cylinder (5) and the fourth cylinder (12) are provided with an external thread (6), the third cylinder (5) is provided with a spline (7), the third cylinder (5) is connected to the fifth cylinder (9) via a fifth chamfered plate (8), the inner wall materials of the first cylinder (2), the second cylinder (11), the third cylinder (5), the fourth cylinder (12), the fifth cylinder (9), the first chamfered plate (3), the second chamfered plate (10), the third chamfered plate (4), the fourth chamfered plate (13) and the fifth chamfered plate (8) are all made of tough materials, and the first chamfered plate (3), the second chamfered plate (10), the third chamfered plate (4), the fourth chamfered plate (13) and the fifth chamfered plate (8) are all hollow plates. One end of the roller body is connected to the first chamfered plate by surfacing welding, the other end of the first chamfered plate is connected to the first cylinder by surfacing welding, the other end of the roller body is connected to the second chamfered plate, the second chamfered plate is connected to the second cylinder, the second cylinder is connected to the fourth chamfered plate, and the fourth chamfered plate is connected to the fourth cylinder by surfacing welding; the third cylinder is connected to the third chamfered plate, and the first cylinder is connected to the third chamfered plate by surfacing welding.

2. The hot straightening work roll according to claim 1, characterized in that: The material of the roller lining (14) is made of carbon steel or 42 chromium molybdenum.

3. The hot straightening work roll according to claim 1, characterized in that: The spline (7) is made by a cold forming process.

4. The hot straightening work roll according to claim 1, characterized in that: The first cylinder (2), the second cylinder (11), the third cylinder (5), the fourth cylinder (12), the fifth cylinder (9), the first chamfered plate (3), the second chamfered plate (10), the third chamfered plate (4), the fourth chamfered plate (13) and the fifth chamfered plate (8) are located on the same horizontal line as the center of the cold water channel (15).

5. The hot straightening work roll according to claim 4, characterized in that: The first chamfered plate (3), the second chamfered plate (10), the third chamfered plate (4), the fourth chamfered plate (13) and the fifth chamfered plate (8) are hollow plates with arcs.

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