Glass roll neck quench and anneal process

Abstract

The present application relates to a glass roller head quenching and annealing process, aiming at the high-frequency quenching process of the glass roller head with the material of 2Cr13 / 20CrNiMo, using the heating depth characteristics of high-frequency equipment and the characteristics of double cooling combination, completing the quenching process of the product with higher hardness, shallow hardened layer and better mechanical properties on the surface of the hollow shaft type piece, which is simple to operate, short in processing period, provides the processing technology for the product with inconsistent hardness, adopts direct quenching or annealing and re-quenching according to the different hardness, and uses multiple and superimposed heating methods in the annealing process, which can effectively eliminate the stress existing in the original quenching process and reduce the risk of re-quenching cracking, finally taking the glass roller head with the outer circle of φ300mm, the inner hole of φ220mm and the material of 2Cr13 and the glass roller head with the outer circle of φ280mm, the inner hole of φ220mm and the material of 2Cr13 as examples to verify the process results. After the process verification, the present process has good stability, the hardness value and the hardened layer depth meet the relevant requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of glass roller head quenching annealing process for the surface of material 2Cr13 / 20CrNiMo glass roller head heat treatment, using this process quenching annealing, reach the purpose of strengthening hardness and homogenization organization, it is related to glass roller surface hardness strengthening, annealing and quenching process.Belongs to the field of heat treatment. BACKGROUND

[0002] Glass roller product is an important component for manufacturing photovoltaic calendering, and has large market demand and broad prospect.At present, the commonly used material of glass roller at home and abroad is 2Cr13 (upper roller) and 20CrNiMo (lower roller).The process route is as follows: electroslag-solid forging-rough turning blanking-hollow quenching and tempering-semifine adding-stress relief-fine adding finished product delivery.

[0003] Glass roller is a kind of hollow shaft, and the shaft head cooperates with bearing bush to work.Because the shaft head is under great stress, it is required to have certain wear resistance, and the hardness in technical requirements is generally required to be 48-55HRC (which belongs to the higher hardness requirement of this material).The quenching and tempering hardness of glass roller is required to be 200-240HB, which is far lower than the hardness requirement of shaft head.Therefore, in order to meet the use condition, the surface of shaft head must be strengthened to increase the service life.

[0004] The wall thickness of glass roller shaft head is generally 30-50mm, and it is hollow, so it is easy to heat too deep when heated, which affects the quenching and tempering performance of the body.In order to ensure the use performance, the thickness of strengthening layer is required to be ≤7mm, and high-frequency quenching is generally used to achieve this. SUMMARY

[0005] The purpose of the present application is to overcome the deficiencies in the prior art and provide a glass roller shaft head quenching annealing process for improving the hardness of glass roller shaft head to increase the strength and wear resistance of glass roller shaft head.

[0006] The technical solution of the present application is as follows:

[0007] A glass roller shaft head quenching annealing process uses the characteristics of high-frequency equipment heating depth and double cooling to complete the quenching process of the product with higher surface hardness, shallow hardened layer and better mechanical properties for hollow shafts, and the specific process steps are as follows:

[0008] Step 1), preparation of equipment tooling: for the quenching of hollow shafts with wall thickness of 30-80mm, high-frequency equipment with frequency of 15-25KHZ is used for quenching, the induction coil is selected to have heating width <10mm, the difference between the diameter of the quenched product and the diameter is 10-20mm, and double water spraying is used for cooling to ensure the heating depth and quenching hardness;

[0009] Step 2), preparation of the roll blank: ensure that the hardness of the quenched and tempered blank is 200-240 HB, and ensure that the base structure of the high-frequency surface quenching meets the requirements;

[0010] Step 3), quenching process: the quenching temperature of the quenched and tempered heat treatment of 2Cr13 is 990-1100℃, and the quenching temperature of the quenched and tempered heat treatment of 20CrNiMo is 880-910℃, and oil cooling or water-based liquid cooling is adopted; high-frequency quenching is carried out at a temperature 15-30℃ higher than the quenched and tempered heat treatment; that is, the surface heat treatment quenching temperature of 2Cr13 is 1050-1130℃, and the surface heat treatment quenching temperature of 20CrNiMo is 895-940℃; double cooling system is adopted for cooling, the first cooling is carried out by using the water spraying device on the induction coil, the pressure is controlled at 0.012-0.015MPa, and the high-frequency induction coil is directly opposite the corresponding area to the shaft head part for rapid cooling, so as to obtain the required surface hardness, that is, the hardened layer is ≤7mm, and the hardness value is 48-55HRC; the second cooling is carried out by adding a cooling water spraying system at a distance of 30-60mm from the induction coil, and the water pressure is maintained at 0.1-0.15MPa, and the main purpose is to reduce the temperature, reduce the temperature of the area above the shaft head radius 10mm in depth in the high-frequency heating, and avoid self-tempering and reduce the hardness of the surface after quenching; the hardness value after quenching is between 48-51HRC; after quenching, stress relief annealing is carried out, the annealing temperature is 170-190℃, and the holding time is 5-8h;

[0011] Step 4), annealing process: for the quenched hardness lower than the technical requirement of 48-55HRC caused by operation failure in the quenching process; it is necessary to re-quench; the re-quenching is carried out according to the hardness of the glass roller shaft head by two methods:

[0012] Step 4.1), when the hardness is ≤45HRC, the quenching process of step 3) is re-executed;

[0013] Step 4.2), when the hardness is between 45-48HRC, induction annealing is needed before the quenching of step 3) is carried out; the specific induction annealing method is as follows: the original high-frequency equipment is used, the original moving speed is used for induction heating, the induction heating is carried out in a temperature superposition mode, the first heating is carried out at 10% of the original power, the heating position instantaneous temperature is 50-80℃; the second heating is carried out after 10-40s, the second heating position instantaneous temperature reaches 100-280℃; the third heating is carried out after the same time, the third heating position instantaneous temperature reaches 300-520℃; the fourth heating is carried out after the same time, the fourth heating position instantaneous temperature reaches 550-750℃; after air cooling, the hardness value is lower than 40HRC, and the re-quenching condition is met; the quenching process of step 3) is re-executed.

[0014] The application has the following advantages:

[0015] 1) It can utilize the heating depth characteristics of high-frequency equipment and the combination of dual cooling to complete the quenching process of hollow shaft parts, achieving high surface hardness, shallow hardened layer, and good mechanical properties. The operation is simple and the processing cycle is short.

[0016] 2) Handling products with inconsistent hardness is relatively simple. Products with lower hardness (≤45HRC) can be directly quenched again on the original equipment without annealing, saving time. Products with higher hardness (45-48HRC) can be annealed on the original equipment; only the annealing induction coil needs to be replaced. Compared to conventional furnace annealing, this saves energy.

[0017] 3) The annealing process is carried out by multiple and superimposed heating methods, which can effectively eliminate the stress existing in the original quenching process and reduce the risk of cracking during re-quenching.

[0018] 4) Induction hardening is followed by tempering, which further relieves stress and ensures the product's performance. The operation is simple and the processing cycle is short. Detailed Implementation

[0019] Example 1: A quenching and annealing process for glass roller shaft heads utilizes the heating depth characteristics of high-frequency equipment and the combination of dual cooling to achieve a quenching process for hollow shaft parts with high surface hardness, a shallow hardened layer, and good mechanical properties. The process results are verified using a glass roller shaft head with an outer diameter of φ300mm, an inner diameter of φ220mm, and a material of 2Cr13. The specific process steps are as follows:

[0020] Step 1) Preparation of equipment and tooling: For quenching of hollow shafts with a wall thickness of 30-80mm, a high-frequency equipment with a frequency of 15-25KHZ is used. The induction coil is φ312mm with a heating width of 8mm. The induction coil has φ2 evenly distributed water spray holes. A φ450 water spray ring is installed 46mm behind the induction coil.

[0021] Step 2) Preparation of the blank state: Ensure that the hardness value of the quenched and tempered blank is between 215-225 HB;

[0022] Step 3) Quenching process: Induction coil movement parameter 300, power parameter 660, workpiece rotation parameter 8. During the process, the temperature measurement shows that the highest temperature of the heating area is 1120℃. The first cooling is the induction coil's own cooling, with a water spray pressure of 0.014MPa. The second cooling is a water spray ring 46mm behind the induction coil, with a water spray pressure of 0.13MPa. After cooling for 1-2 minutes, the shaft head returns to normal temperature and is ready for hardness testing. The surface hardness is tested, and the hardness value is 48.2-49.8HRC. The hardness at a depth of 8mm on the end face is tested, and the hardness value is 220HB. The shaft is then placed in a heating furnace for stress-relief tempering, with a holding temperature of 170±10℃ and a time of 6 hours.

[0023] Example 2: A glass roller shaft head quenching annealing process, with a glass roller shaft head outer circle φ280mm inner hole φ220mm, annealing quenching process for material 2Cr13 process results verification, the specific process steps are as follows:

[0024] Step 1), preparation of equipment tooling: using high frequency equipment with frequency of 15-25KHZ, induction coil φ294mm, heating width 8mm, induction coil with φ2 uniform water spray hole, install a φ450 water spray ring 46mm behind the induction coil;

[0025] Step 2), preparation of roller blank state: original roller blank quenching and tempering hardness 215-225HB;

[0026] Step 3), first high frequency surface heating, and after secondary cooling, detect the hardness value of surface shaft head 46-47.6HRC, not meet the technical requirements;

[0027] Step 4), annealing process: because the surface hardness is 46-47.6HRC, not meet the technical requirements, need to be annealed; the specific operation is as follows:

[0028] Using high frequency equipment with frequency of 15-25KHZ for quenching, induction coil φ294mm, heating width 8mm, induction coil without water spray hole; induction coil moving parameter 300, workpiece rotating parameter 8; first heating, power parameter 56, temperature display maximum temperature 65℃; interval 35s for secondary heating, power parameter 65, temperature maximum value 130℃; interval 28s for third heating, power parameter 80, temperature maximum value 443℃; interval 18s for fourth heating, power parameter 100, temperature maximum value 743℃; after cooling in air, detect surface hardness 35-38HRC, with quenching conditions again;

[0029] Step 5), re quenching process: using high frequency equipment with frequency of 15-25KHZ, induction coil φ294mm, heating width 8mm, induction coil with φ2 uniform water spray hole; install a φ450 water spray ring 46mm behind the induction coil;

[0030] Induction coil moving parameter 300, power parameter 560, workpiece rotating parameter 8, induction coil water spray pressure 0.012MPa, water spray ring water spray pressure 0.12MPa, temperature display maximum temperature 1075℃ in the process; cooling 1-2min, shaft head restore normal temperature, with hardness detection conditions; detect surface layer hardness, hardness value 49.5-51.2HRC; end face detection depth 8mm hardness, hardness value 200HB; into the heating furnace for stress relief tempering, holding temperature 180±10℃, time 8h.

Claims

1. A glass roll neck quench and anneal process characterized by: The high frequency equipment is used to heat the hollow shafts, and the double cooling system is used to cool the shafts. The surface of the hollow shafts has high hardness, shallow hardened layer and good mechanical properties. The process steps are as follows: Step 1, preparation of equipment and tooling: for the hollow shafts with wall thickness of 30-80mm, high frequency equipment with frequency of 15-25KHZ is used for quenching. The induction coil has heating width of less than 10mm, and the difference between the diameter of the induction coil and the diameter of the shaft is 10-20mm. The double water spraying system is used for cooling to ensure the heating depth and quenching hardness. Step 2, preparation of roll blank: the hardness of the quenched and tempered blank is 200-240HB, and the base layer structure of the high frequency surface quenching meets the requirements. Step 3, quenching process: the quenching temperature of 2Cr13 is 990-1100℃, and the quenching temperature of 20CrNiMo is 880-910℃. The oil or water-based liquid cooling is used. The high frequency quenching is higher than the quenching temperature of the quenched and tempered heat treatment by 15-30℃. The surface heat treatment quenching temperature of 2Cr13 is 1050-1130℃, and the surface heat treatment quenching temperature of 20CrNiMo is 895-940℃. The double cooling system is used for cooling. The first cooling uses the water spraying device on the induction coil, and the pressure is controlled at 0.012-0.015MPa. The high frequency induction coil is used for rapid cooling of the corresponding area to the shaft head to obtain the required surface hardness, i.e. the hardened layer is less than 7mm, and the hardness value is 48-55HRC. The second cooling is the cooling spraying system installed at a distance of 30-60mm from the induction coil, and the water pressure is maintained at 0.1-0.15MPa. The main purpose is to reduce the temperature of the area above the shaft head radius of 10mm in the high frequency heating to avoid self tempering and reduce the hardness of the surface after quenching. The hardness value after quenching is 48-51HRC. After quenching, stress relief annealing is carried out at a temperature of 170-190℃ for 5-8h. Step 4, annealing process: for the quenched hardness lower than the technical requirement of 48-55HRC due to operation error in the quenching process, re-quenching is needed. The re-quenching is carried out according to the hardness of the glass roller shaft head in two ways: Step 4.1, the hardness is less than or equal to 45HRC, and the quenching process is re-executed according to step 3. Step 4.2) between the hardness 45-48HRC, need to carry out induction annealing after the execution of step 3) quenching;Specific induction annealing method is: using the original high frequency equipment, with the original moving speed is inducted to heat, induction heating is carried out using temperature superposition, first 10% of the original power is heated, the heating site instantaneous temperature is 50-80℃;Interval 10-40s is heated twice, the instantaneous temperature of the second heating site reaches 100-280℃;Interval the same time is heated three times, the instantaneous temperature of the third heating site reaches 300-520℃;Interval the same time is heated four times, the instantaneous temperature of the fourth heating site reaches 550-750℃;Air cooling hardness value is less than 40HRC, has the quenching condition again;According to step 3) re execute quenching process.