Destressing equipment and method for steel rolling roll collar

Abstract

The invention relates to the technical field of roller ring destressing, in particular to destressing equipment and method for a steel rolling roller ring. The destressing equipment for the steel rolling roll collar comprises a heating furnace and a furnace car used in cooperation with the heating furnace, the heating furnace comprises a heating chamber on the upper portion and a furnace car parking chamber on the lower portion, and the heating chamber is matched with a door body. A first aerogel felt, a supporting seat, a bearing brick and a bearing plate are sequentially arranged on the furnace car in the height direction of the heating furnace from bottom to top, a roll collar frame is arranged at the upper end of the bearing plate in a matched mode, the roll collar frame is used for containing a roll collar, and when the furnace car is parked in the furnace car parking chamber, the supporting seat corresponds to the boundary position of the heating chamber and the furnace car parking chamber. And the bearing bricks and the bearing plate are positioned in the heating chamber. The method has the advantage that the safety and the stability of the roll collar in the steel rolling production process can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of roller ring stress relief, and in particular to a stress relief device and method for a steel rolling roller ring. Background Art

[0002] The Chinese patent application with application number 202110419501.3 discloses a heat treatment method for a common cemented carbide roller ring, comprising the following processing steps: preparing a carbon black slurry spray agent; performing rough grinding on the roller ring; using a carbon black slurry spraying device to uniformly spray the roller ring; heating the roller ring; quickly cooling the roller ring by air cooling; annealing the roller ring, controlling the annealing temperature to 460-500 degrees Celsius, holding time to 4-6 hours, and slowly cooling to room temperature with the furnace.

[0003] In the above technical scheme, the purpose is to form a layer of tungsten carbide on the surface of the roller ring to reduce the grain fragmentation during the rolling process, optimize the roller ring from the outside, and thus improve the production strength of the roller ring. However, in the existing steel bar rolling process, the hot rolled piece contacts the surface of the rolling groove, which causes the surface temperature of the roller ring to rise. This part of the metal will expand, and the temperature of the metal in the deep layer of the roller ring will increase less, which will cause compressive stress on the metal on the surface of the roller ring; when the surface layer of the roller ring is rapidly cooled by cooling water, the surface metal shrinks, but the deep metal shrinks less than the surface metal, which will cause stress on the surface metal. A tensile stress is generated. Such repeated alternating thermal stress can easily cause thermal fatigue cracks in the roller ring, resulting in microcracks at the bottom of the roller ring groove. The cracks caused by this reason are usually reprocessed on a lathe to remove the part with fine cracks on the surface and then continue to be used. Once the roller is not replaced in time, the microcracks will extend, making the microcracks wider and deeper, and cracks will appear. In severe cases, the roller ring will burst and rupture, leading to production safety accidents in the steel mill. Therefore, allowing the stress inside the roller ring to damage the roller ring still poses certain safety hazards.

[0004] Therefore, removing the residual stress from the inside of the roller ring after use due to processing to slow down the formation speed of thermal cracks in the roller ring is a technical problem that still needs to be solved in the prior art. Summary of the invention

[0005] The object of the present invention is to provide a stress relief device and method for a steel rolling roller ring, which can remove residual stress caused by processing from the inside of the roller ring to slow down the formation speed of thermal cracks in the roller ring.

[0006] To achieve the above-mentioned purpose, the present invention discloses a stress relief device for steel rolling roller rings, comprising a heating furnace and a furnace car used in conjunction with the heating furnace, the heating furnace comprising an upper heating chamber and a lower furnace car parking chamber, the heating chamber is equipped with a door body, and the furnace car is provided with a first aerogel felt, a support seat, load-bearing bricks and a load-bearing plate in sequence from bottom to top along the height direction of the heating furnace, the upper end of the load-bearing plate is equipped with a roller ring frame, the roller ring frame is used to place roller rings, and when the furnace car is parked in the furnace car parking chamber, the support seat corresponds to the boundary position between the heating chamber and the furnace car parking chamber, and the load-bearing bricks and the load-bearing plates are located in the heating chamber.

[0007] The roller ring that is on standby at the site after the steel bar rolling work is removed, the inner hole sleeve in the roller ring is removed, and the roller ring without the inner hole sleeve is placed in the roller ring frame and arranged in an array in sequence. The operator moves the support car into the heating furnace, and the support car makes the support seat correspond to the boundary position between the heating chamber and the furnace car parking room, so that the support seat is matched with the support platform. The first aerogel felt isolates the heat of the heating chamber from the lower side of the heating chamber. After closing the door body, start heating the roller ring without the inner hole sleeve according to the process temperature curve.

[0008] The present invention utilizes a heating furnace to heat the roller ring after steel bar rolling according to a process temperature curve, so that the temperatures of various parts inside the roller ring gradually tend to be consistent, thereby reaching a thermal equilibrium state, and the stress inside the roller ring will gradually reach a balanced state, thereby eliminating the thermal stress generated by the temperature difference inside and outside the roller ring, thereby effectively removing the stress remaining from the inside of the roller ring due to processing, and reducing the risk of cracks and bursts of the roller ring due to thermal fatigue during the steel rolling process. The present invention has the advantage of being able to improve the safety and stability of the roller ring in the steel rolling production process.

[0009] Among them, the heating chamber is a kiln built with furnace bricks and located on the upper side of the support platform, and the mounting method of the kiln is the same as the existing structure; the support vehicle is a transport vehicle with a lifting function in the prior art that has a hinge mechanism or an electric hydraulic push rod group as a lifting mechanism.

[0010] Preferably, the side walls of the support seat along the width direction of the heating furnace abut against the inner walls of the support platform along the width direction of the heating furnace, and the side walls of the support seat along the depth direction of the heating furnace abut against the rear wall of the support platform and the door body, the support seat and the lower end surface of the support platform are located in the same plane, the first aerogel felt is located at the lower side of the support seat and the support platform, and the second aerogel felt is provided on the side of the door body of the heating furnace close to the heating chamber, and the second aerogel felt is in the shape of a U-shaped letter "U".

[0011] When the furnace car is parked in the furnace car parking room, the first aerogel felt simultaneously seals the lower end surfaces of the support seat and the support platform, thereby ensuring the sealing effect of the heating chamber from the lower side of the heating chamber; the second aerogel felt is used to seal the gap between the door body of the heating furnace and the heating chamber, thereby ensuring the sealing effect of the heating chamber from the opening of the heating chamber, thereby maintaining the temperature of the heating chamber and preventing the need for continuous heating after the heat in the heating chamber is conducted away, thereby preventing energy loss.

[0012] Preferably, the support seat is in a U-shaped structure, and a vacuum cavity is arranged inside the support seat along the cross-sectional shape of the U-shaped structure.

[0013] By arranging a vacuum cavity between the structures formed by the inner and outer sides of the support seat, a vacuum is formed, thereby reducing heat conduction and convection generated between the inner and outer sides of the support seat, thereby achieving an excellent heat insulation effect.

[0014] Preferably, the load-bearing bricks include glass fiber and rock wool, so that the load-bearing bricks can support the bearing plate and provide insulation at the same time.

[0015] Preferably, the load-bearing brick is provided with a stopper at one end close to the support seat.

[0016] The stopper is used to prevent the load-bearing bricks from sliding along the upper end surface of the support seat during the transfer of the support vehicle, thereby affecting the supporting effect of the roller ring frame.

[0017] Preferably, the roller ring frame includes a frame body and a base plate, and the frame body and the base plate are detachably connected to facilitate disassembly and assembly of the frame body. After a layer of roller rings is stacked, the frame body is placed on the base plate to carry more roller rings, thereby increasing the number of roller rings heated at a single time.

[0018] Preferably, the frame body and the bottom plate are both made of graphite, thereby reducing the impact of high temperature on the roller ring frame while ensuring the load-bearing effect of the roller ring frame; compared with other high-temperature resistant alloy frames, the use of a roller ring frame made of graphite can reduce costs.

[0019] The present invention also discloses a stress relief method for a steel rolling roller ring, comprising the following steps: S1. Release the pressure of the hydraulic device on the roller and clamp out the roller ring group; S2. After removing the inner sleeve of the roller ring assembly, place the roller ring in the roller ring frame; S3, sending the support table with the roller ring into the heating furnace, and closing the door of the heating furnace; S4, start heating, heat the roller ring in the heating furnace to 400 degrees Celsius, and keep it for 8 hours; S5, heating the roller ring at 400 degrees Celsius to 700 degrees Celsius and maintaining it for 10 hours; S6, start cooling, reduce the roller ring temperature from 700 degrees Celsius to 100 degrees Celsius, and keep it for 12 hours; S7, after the roller ring is lowered to room temperature, it is kept for 6 hours. After the roller ring is at room temperature, the stress removal of the roller ring is completed.

[0020] The roller ring after steel bar rolling is heated in a heating furnace according to the process temperature curve. The temperature of each part inside the roller ring is gradually tended to be consistent by gradually increasing the temperature and keeping the temperature in a heat preservation manner, thereby achieving a thermal equilibrium state, and the stress inside the roller ring will gradually reach a balanced state, thereby eliminating the thermal stress caused by the temperature difference inside and outside the roller ring; and then the roller ring is gradually cooled and kept in a heat preservation manner. When the roller ring returns to room temperature, it can be taken out and reused, thereby slowing down the formation speed of thermal cracks in the roller ring.

[0021] Preferably, the process of step S5 is as follows; S51, heating the roller ring at 400 degrees Celsius to 600 degrees Celsius, and maintaining the temperature for 4 hours; S52, heating the roller ring at 600 degrees Celsius to 700 degrees Celsius, and maintaining the temperature for 10 hours.

[0022] Compared with heating the roller ring directly from 400 degrees Celsius to 700 degrees Celsius, the slow temperature increase will cause inconsistent shrinkage inside and outside and produce thermal cracks due to the rapid temperature change. Slow heating can make the shrinkage of the inside and outside of the roller ring consistent, achieving the effect of releasing the internal stress of the roller ring.

[0023] Preferably, in step S7, after the roller rings have cooled to below 100 degrees Celsius, the roller ring stand with the roller rings is taken out and the roller rings are allowed to cool naturally to room temperature. The roller rings can be cooled naturally outdoors to improve the use efficiency of the heating furnace.

[0024] The present invention can make the temperatures of various parts inside the roller ring gradually tend to be consistent, thereby achieving a thermal equilibrium state, and the stress inside the roller ring will gradually reach a balanced state, thereby eliminating the thermal stress generated by the temperature difference inside and outside the roller ring, and has the advantage of slowing down the formation speed of thermal cracks in the roller ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention.

[0026] Figure 2 It is a structural schematic diagram of the support vehicle in the present invention.

[0027] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at point A in the middle.

[0028] In the figure: 11, heating furnace; 12, support platform; 13, heating chamber; 14, second aerogel felt; 15, support vehicle; 16, transport track; 17, furnace vehicle parking room; 20, first aerogel felt; 21, support seat; 211, vacuum chamber; 22, load-bearing bricks; 221, stopper; 23, load-bearing plate; 24, bottom plate; 25, frame. DETAILED DESCRIPTION

[0029] The present invention will be further described below based on the accompanying drawings and specific embodiments.

[0030] Depend on Figure 1 As shown, the present embodiment discloses a stress relief device for a steel rolling roller ring, comprising a heating furnace 11 and a supporting vehicle 15 used in conjunction with the heating furnace 11, the heating furnace comprising an upper heating chamber 13 and a furnace vehicle parking chamber 17 at the bottom, a lifting mechanism identical to the prior art structure is provided in the supporting vehicle 15 for lifting and lowering the upper end surface of the supporting vehicle 15, a conveying track 16 is arranged between the supporting vehicle 15 and the heating furnace 11, a heating chamber 13 is provided in the heating furnace 11, a supporting platform 12 for isolating the heating chamber 13 from heat is provided at the lower side of the heating chamber 13 in conjunction with the supporting vehicle 15, the heating chamber 13 is a furnace kiln located on the upper side of the supporting platform 12 and built with furnace bricks, the mounting method of the furnace kiln is the same as the prior art structure, the top of the heating chamber 13 is designed as an arc, thereby improving the stability and durability of the structure, ensuring the uniform distribution of temperature and pressure in the heating chamber 13, thereby improving the quality and performance of the heated roller ring; Figure 2 As shown, the support vehicle 15 is provided with a first aerogel felt 20, a support seat 21, a load-bearing brick 22 and a load-bearing plate 23 in sequence from bottom to top along one side in the height direction of the heating furnace 11. The upper end of the load-bearing plate 23 is equipped with a roller ring frame, and the roller ring frame includes a frame body 25 and a bottom plate 24 both made of graphite. The frame body 25 and the bottom plate 24 are detachably connected. The load-bearing plate 23 can support the graphite frame body 25, reduce the pressure of the graphite frame body 25 on the load-bearing brick 22, and prevent the load-bearing brick 22 located under the graphite frame body 25 from being concave after the load-bearing brick 22 is used for a long time; the support seat 21 The support seat 21 is in a U-shaped structure, and a vacuum cavity 211 is arranged in the support seat 21 along the cross-sectional shape of the U-shaped structure. The first aerogel felt 20 is located at the lower side of the support seat 21 and the support platform 12. The heating chamber 13 is sealed from the lower side of the heating chamber 13 by the first aerogel felt 20 and the vacuum cavity 211 in the support seat 21, so as to insulate the heating chamber 13 and reduce the energy loss of heating the heating chamber 13. The door body of the heating furnace 11 is provided with a second U-shaped aerogel felt 14 near the heating chamber 13. Figure 3 As shown, a stopper 221 is provided at one end of the load-bearing brick 22 close to the support seat 21, and the load-bearing brick 22 is a special brick containing glass fiber and rock wool.

[0031] This embodiment also discloses a stress relief method for a steel rolling roller ring, comprising the following steps: S1. Release the pressure of the hydraulic device on the roller and clamp out the roller ring group; S2. After removing the inner sleeve of the roller ring and the roller ring assembly, place the roller ring in the roller ring frame; S3, sending the support table 12 with the roller ring into the heating furnace 11, and closing the door of the heating furnace 11; S4, start heating, heat the roller ring in the heating furnace 11 to 400 degrees Celsius, and keep it for 8 hours; S5, heating the roller ring at 400 degrees Celsius to 700 degrees Celsius and keeping it for 10 hours, which includes heating the roller ring at 400 degrees Celsius to 600 degrees Celsius and keeping it for 4 hours, and then heating the roller ring at 600 degrees Celsius to 700 degrees Celsius and keeping it for 10 hours; S6, start cooling, reduce the roller ring temperature from 700 degrees Celsius to 100 degrees Celsius, and keep it for 12 hours; S7, take out the roller ring stand with the roller ring, and allow the roller ring to cool naturally to room temperature. After the roller ring is at room temperature, keep it for 6 hours, and the stress removal of the roller ring is completed.

[0032] The roller rings that are on standby at the site after the steel bar rolling work are removed, the inner hole sleeves in the roller rings are removed, and the roller rings without inner hole sleeves are placed in an array in the roller ring frame in sequence. The operator uses the support vehicle 15 to move the roller rings into the heating furnace 11 through the conveying track 16, and the side walls of the support seat 21 along the width direction of the heating furnace 11 are abutted against the inner walls of the support platform 12 along the width direction of the heating furnace 11, and the side walls of the support seat 21 along the depth direction of the heating furnace 11 are abutted against the rear wall of the support platform 12 and the door body, so that the support vehicle 15 is aligned with the support platform 12, and the operator lifts the support vehicle 15 through the lifting structure to make the lower end surface of the support seat 21 flush with the lower end surface of the support platform 12, so that the first aerogel felt 20 seals the lower end surface of the support seat 21 and the support platform 12, and after closing the heating furnace 11, the roller rings without inner hole sleeves are heated according to the process temperature curve.

[0033] When heating starts, the roller ring is heated to 400 degrees Celsius and maintained for 8 hours, and then the temperature of the entire roller ring is slowly increased from the outside to the inside; the roller ring at 400 degrees Celsius is heated to 600 degrees Celsius and maintained for 4 hours. Since the roller ring has been heated to 400 degrees Celsius as a whole, the external temperature is increased at this time, the surface temperature of the roller ring is greater than the internal temperature of the roller ring, the expansion of the surface of the roller ring is greater than the expansion of the inside, and because the temperature difference between the inside and outside of the roller ring is lower than that during the rolling operation, the stress inside the roller ring is slowly released, and then the roller ring at 600 degrees Celsius is heated to 700 degrees Celsius and maintained for 10 hours, and the internal stress of the roller ring is continued to be slowly released. At this time, the external temperature of the roller ring is slowly transmitted to the inside of the roller ring, and the temperatures inside and outside the entire roller ring are basically the same, and the stress release is completed.

[0034] When starting to cool down, lower the roller ring from 700 degrees Celsius to 100 degrees Celsius, keep it for 12 hours, and cool it down slowly to prevent new cracks caused by the temperature difference inside and outside the roller ring. After the roller ring cools to below 100 degrees Celsius, take out the roller ring stand with the roller ring, let the roller ring cool naturally to room temperature, and let the roller ring cool naturally outdoors.

[0035] The stress test results of various positions inside the roller ring after being processed by this solution are shown in the following table: Roller ring stress test table The measured product specifications 1 and 2 in the roller ring stress detection table are respectively the upper roller ring and the lower roller ring after the steel bar rolling work; the distance end face position in the roller ring stress detection table is the distance between the X-ray irradiation position in the X-ray diffraction method detection and the actual position of the axial end face of the roller ring.

[0036] After the two samples were tested by Shanghai Sheke Optoelectronics Technology Co., Ltd., the internal stress of the roller ring was reduced by more than 70% after being treated with this solution.

Claims

1. A stress relief device for a steel rolling roller ring, comprising a heating furnace and a furnace car used in conjunction with the heating furnace, the heating furnace comprising an upper heating chamber and a lower furnace car parking chamber, the heating chamber being equipped with a door body, characterized in that: The furnace car is provided with a first aerogel felt, a support seat, load-bearing bricks and a load-bearing plate in sequence from bottom to top along the height direction of the heating furnace. The upper end of the load-bearing plate is equipped with a roller ring frame, and the roller ring frame is used to place roller rings. When the furnace car is parked in the furnace car parking room, the support seat corresponds to the boundary position between the heating chamber and the furnace car parking chamber, and the load-bearing bricks and the load-bearing plate are located in the heating chamber.

2. A stress relief device for a steel rolling roll ring according to claim 1, characterized in that: The side wall of the support seat along the width direction of the heating furnace abuts against the inner wall of the support platform along the width direction of the heating furnace, and the side wall of the support seat along the depth direction of the heating furnace abuts against the rear wall of the support platform and the door body. The support seat and the lower end surface of the support platform are located in the same plane, the first aerogel felt is located at the lower side of the support seat and the support platform, and the second aerogel felt is provided on the side of the door body of the heating furnace close to the heating chamber, and the second aerogel felt is in the shape of a U-shaped letter "U".

3. A stress relief device for a steel rolling roll ring according to claim 1 or 2, characterized in that: The support seat is in a U-shaped structure, and a vacuum cavity is arranged in the support seat along the cross-sectional shape of the U-shaped structure.

4. A stress relief device for a steel rolling roller ring according to claim 3, characterized in that: The components of the load-bearing bricks include glass fiber and rock wool.

5. The stress relief device for a steel rolling roller ring according to claim 4, characterized in that: The load-bearing brick is provided with a stopper at one end close to the support seat.

6. The stress relief device for a steel rolling roller ring according to claim 1, characterized in that: The roller ring frame comprises a frame body and a bottom plate, and the frame body and the bottom plate are detachably connected.

7. The stress relief device for a steel rolling roller ring according to claim 6, characterized in that: The frame and the bottom plate are both made of graphite.

8. A stress relief method for a steel rolling roller ring, characterized in that The steps include: S1. Release the pressure of the hydraulic device on the roller and clamp out the roller ring group; S2. After removing the inner sleeve of the roller ring assembly, place the roller ring in the roller ring frame; S3, sending the support table with the roller ring into the heating furnace, and closing the door of the heating furnace; S4, start heating, heat the roller ring in the heating furnace to 400 degrees Celsius, and keep it for 8 hours; S5, heating the roller ring at 400 degrees Celsius to 700 degrees Celsius and maintaining it for 10 hours; S6, start cooling, reduce the roller ring temperature from 700 degrees Celsius to 100 degrees Celsius, and keep it for 12 hours; S7, after the roller ring is lowered to room temperature, it is kept for 6 hours. After the roller ring is at room temperature, the stress removal of the roller ring is completed.

9. A stress relief method for a steel rolling roll ring according to claim 8, characterized in that: The process of step S5 is as follows; S51, heating the roller ring at 400 degrees Celsius to 600 degrees Celsius and maintaining it for 4 hours; S52, heating the roller ring at 600 degrees Celsius to 700 degrees Celsius, and maintaining the temperature for 10 hours.

10. A stress relief method for a steel rolling roller ring according to claim 8, characterized in that: In the step S7, after the roller ring is cooled to below 100 degrees Celsius, the roller ring frame with the roller ring is taken out and the roller ring is allowed to cool naturally to room temperature.

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