A manufacturing process for high-strength bearing rings

Abstract

This invention discloses a high-strength bearing ring manufacturing process, with the following specific steps: Step 1: Select bearing ring production bars, inspect the bars, conduct trial runs of the production equipment, and provide technical instructions to the staff; Step 2: Cold-draw the bars using a cold-drawing machine to make the outer diameter of the bars the required size for the bearing rings. Then, axially drill holes in the cold-drawn bars using a CNC lathe, with the hole diameter matching the inner diameter of the bearing rings. Next, radially cut the bars according to the required dimensions to obtain blanks; Step 3: Before forging, subject the blanks obtained in Step 2 to induction heating treatment to improve their plasticity and reduce deformation resistance. The heated raw material is then upsetting on a forging hammer. This process accumulates a large strain within the bearing rings, thereby refining the grains, achieving high strength characteristics, significantly increasing yield strength, reducing deformation, enhancing durability, and effectively extending the service life of the bearing rings.

Description

Technical Field

[0001] This invention belongs to the field of bearing processing technology, specifically relating to a high-strength bearing ring manufacturing process. Background Technology

[0002] Bearings are essential components in modern machinery. Their primary function is to support rotating parts, reduce friction during movement, and ensure rotational accuracy. The bearing manufacturing process mainly includes raw material preparation, inner and outer ring machining, steel ball or roller machining, cage machining, and bearing assembly. Among these, forging, heat treatment, and grinding are key processes that significantly impact the quality and performance of the bearing. Bearing rings are annular parts of radial rolling bearings with one or more raceways, requiring specialized bearing ring manufacturing processes.

[0003] Existing bearing ring manufacturing processes cannot produce bearing rings with high strength characteristics, low yield strength, easy deformation, large thermal stress due to alternating hot and cold temperatures, high friction, and easy thermal fatigue cracks. The overall process steps are relatively complex, inconvenient to operate, and have poor applicability. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength bearing ring manufacturing process to solve the problems mentioned in the background art, such as the existing bearing ring manufacturing process, which produces bearing rings that cannot obtain high strength characteristics, have low yield strength, are easy to deform, have large thermal stress due to alternating hot and cold temperatures, have large frictional force, are prone to thermal fatigue cracks, and have relatively complex overall process steps, are inconvenient to operate, and have poor applicability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a manufacturing process for high-strength bearing rings, the specific manufacturing process steps of which are as follows: Step 1: Select the bearing ring production bar stock, inspect the bar stock, conduct trial operation of the production equipment, and provide technical instructions to the staff; Step 2: The bar stock is cold-drawn using a cold drawing machine to make the outer diameter of the bar stock the size required for the bearing ring. Then, the cold-drawn bar stock is axially drilled using a CNC lathe with the hole diameter being the inner diameter of the bearing ring. Finally, the bar stock is radially cut according to the required size to obtain the blank. Step 3: Before forging, the billet obtained in step 2 is subjected to induction heating treatment to improve its plasticity and reduce deformation resistance. The heated raw material is upsetting on a forging hammer to form a preliminary ring shape. The upset billet is extruded in a mold to form a ring semi-finished product that is closer to the final shape. Step 4: The processed semi-finished rings are subjected to constant temperature heat treatment at 800-950℃ for 80-130 minutes, followed by crystallization annealing with quenching medium for 50-80 minutes, and then unidirectional rolling multiple times to form the rings. The equivalent variable of each unidirectional rolling is 1.5-3. Step 5: Use a high-frequency heating furnace to heat the surface of the workpiece at the fastest possible heating speed, generally greater than 600℃ / second, to rapidly heat to 980℃~1100℃. Spray quenching medium onto the heated bearing ring surface for crystallization annealing for 80~100min. After holding at the temperature, cool with the furnace to 145~155℃, then open the furnace door to cool to room temperature. Step Six: After quenching, allow the semi-finished bearing rings to cool naturally. Then, use a plasma spray gun to spray a composite ceramic coating at high temperature. The plasma flow rate of H2 is 2.5L / min, the powder feeding speed is 20g / min, the Ar flow rate is 25L / min, the current is 400A, and the voltage is 50.5V, thereby manufacturing the finished bearing rings. Step 7: Use an industrial camera to photograph the outer surface of the formed bearing ring sample and transmit the image to a connected industrial computer. The industrial computer will then compare and analyze the images to inspect the appearance quality of the bearing ring. Step 8: Technicians use the PLC controller to set the working parameters of the press, place the bearing ring sample that passed the test in Step 6 vertically in the fixture, tighten the bolts on both sides to clamp and fix it, turn on the power of the press to drive the punch head to move downward to squeeze the surface of the bearing ring and test its compressive strength.

[0006] Furthermore, in step one, the inspectors conduct production license testing on the bar stock. Enterprises that purchase imported bar stock that requires statutory inspection should obtain a valid inspection certificate from the supplier. The bar stock can only be put into storage after the relevant indicators have been inspected and qualified.

[0007] Furthermore, in step six, the bearing rings are pre-sandblasted before coating. The semi-finished bearing rings after sandblasting are ultrasonically cleaned with acetone, and then the surface of the semi-finished bearing rings is sandblasted with 24-mesh brown corundum abrasive.

[0008] Furthermore, in step six, the composition ratio of chromium oxide, yttrium oxide, and aluminum oxide powders in the composite ceramic coating is: 80 wt.% chromium oxide powder, 10 wt.% yttrium oxide powder, and 10 wt.% aluminum oxide powder.

[0009] Furthermore, the particle size of the chromium oxide, yttrium oxide, and aluminum oxide powder particles is 40μm to 50μm, and the thickness of the composite ceramic coating is 220μm to 280μm.

[0010] Furthermore, the surface heating temperature in step five must exceed the temperature range of the austenite region, i.e., 723℃~830℃.

[0011] Furthermore, the quenching medium in step five can be one of water, aqueous solution, emulsion, or oily liquid.

[0012] Compared with the prior art, the beneficial effects of the present invention are: (1) The high-strength bearing ring production process selects bearing ring production bars, inspectors inspect the bars, and test the production equipment. Technical instructions are given to the staff to ensure that the bearing ring production is orderly, reduce the error rate, and improve the quality of the product. The bars are strictly inspected to screen out bars that do not meet the standards, thereby improving the quality of the product. The semi-finished bearing rings are quenched and kept warm at 800-950℃ and 980-1100℃ respectively, so that the bearing rings accumulate large strain, thereby achieving grain refinement, obtaining high strength characteristics, greatly improving yield strength, making them less prone to deformation, durable, and effectively extending the service life of the bearing rings.

[0013] (2) The high-strength bearing ring production process provided by this invention has a tightly bonded coating formed by the mixture of chromium oxide, yttrium oxide and aluminum oxide powders. The coating toughness is significantly improved, the thermal stress of alternating hot and cold is low, the friction is small, and it is not easy to generate thermal fatigue cracks. It also has the functions of heat insulation and acid and alkali corrosion resistance, which improves the performance of the bearing ring. The overall process steps are simple, easy to operate, highly creative, and suitable for widespread use. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0015] A manufacturing process for high-strength bearing rings, the specific steps of which are as follows: Step 1: Select the bearing ring production bar stock, inspect the bar stock, conduct trial operation of the production equipment, and provide technical instructions to the staff; Step 2: The bar stock is cold-drawn using a cold drawing machine to make the outer diameter of the bar stock the size required for the bearing ring. Then, the cold-drawn bar stock is axially drilled using a CNC lathe with the hole diameter being the inner diameter of the bearing ring. Finally, the bar stock is radially cut according to the required size to obtain the blank. Step 3: Before forging, the billet obtained in step 2 is subjected to induction heating treatment to improve its plasticity and reduce deformation resistance. The heated raw material is upsetting on a forging hammer to form a preliminary ring shape. The upset billet is extruded in a mold to form a ring semi-finished product that is closer to the final shape. Step 4: The processed semi-finished rings are subjected to constant temperature heat treatment at 800-950℃ for 80-130 minutes, followed by crystallization annealing with quenching medium for 50-80 minutes, and then unidirectional rolling multiple times to form the rings. The equivalent variable of each unidirectional rolling is 1.5-3. Step 5: Use a high-frequency heating furnace to heat the surface of the workpiece at the fastest possible heating speed, generally greater than 600℃ / second, to rapidly heat to 980℃~1100℃. Spray quenching medium onto the heated bearing ring surface for crystallization annealing for 80~100min. After holding at the temperature, cool with the furnace to 145~155℃, then open the furnace door to cool to room temperature. Step Six: After quenching, allow the semi-finished bearing rings to cool naturally. Then, use a plasma spray gun to spray a composite ceramic coating at high temperature. The plasma flow rate of H2 is 2.5L / min, the powder feeding speed is 20g / min, the Ar flow rate is 25L / min, the current is 400A, and the voltage is 50.5V, thereby manufacturing the finished bearing rings. Step 7: Use an industrial camera to photograph the outer surface of the formed bearing ring sample and transmit the image to a connected industrial computer. The industrial computer will then compare and analyze the images to inspect the appearance quality of the bearing ring. Step 8: Technicians use the PLC controller to set the working parameters of the press, place the bearing ring sample that passed the test in Step 6 vertically in the fixture, tighten the bolts on both sides to clamp and fix it, turn on the power of the press to drive the punch head to move downward to squeeze the surface of the bearing ring and test its compressive strength.

[0016] In step one, the inspectors conduct production license testing on the bar stock. Enterprises that purchase imported bar stock that requires legal inspection should obtain a valid inspection certificate from the supplier. The bar stock can only be put into storage after the relevant indicators have been inspected and qualified.

[0017] In step six, the bearing rings are pre-sandblasted before coating. The semi-finished bearing rings after sandblasting are ultrasonically cleaned with acetone, and then the surface of the semi-finished bearing rings is sandblasted with 24-mesh brown corundum abrasive.

[0018] In step six, the composition ratio of chromium oxide, yttrium oxide, and aluminum oxide powders in the composite ceramic coating is: 80 wt.% chromium oxide powder, 10 wt.% yttrium oxide powder, and 10 wt.% aluminum oxide powder.

[0019] Wherein, the particle size of the chromium oxide, yttrium oxide, and aluminum oxide powder particles is 40μm to 50μm, and the thickness of the composite ceramic coating is 220μm to 280μm.

[0020] In step five, the surface heating temperature must exceed the austenite region temperature range of 723℃ to 830℃.

[0021] In step five, the quenching medium can be one of water, aqueous solution, emulsion, or oily liquid.

[0022] In operation, this invention involves: selecting bearing ring production bars; inspecting the bars; conducting trial runs of the production equipment; and providing technical briefings to staff to ensure orderly bearing ring production, reduce the error rate, and improve product quality. Strict inspection of the bars is conducted to screen out those that do not meet standards, further enhancing product quality. The semi-finished bearing rings are then quenched and held at 800–950℃ and 980–1100℃ respectively, accumulating significant strain within the bearing rings, resulting in grain refinement, high strength, significantly increased yield strength, reduced deformation, durability, and effectively extended service life of the bearing rings. The coating formed by the mixture of chromium oxide, yttrium oxide, and aluminum oxide powders provided by this invention has a tight bond, significantly improved coating toughness, low thermal stress under alternating hot and cold temperatures, low friction, and is less prone to thermal fatigue cracks. It also has heat insulation and acid and alkali corrosion resistance functions, improving the performance of bearing rings. The overall process steps are simple, easy to operate, highly innovative, and suitable for widespread application. An industrial camera is used to photograph the outer surface of the formed bearing ring sample and transmit the image to a connected industrial computer. The industrial computer facilitates comparison and analysis to inspect the appearance quality of the bearing ring. Technicians use a PLC controller to set the working parameters of the press, vertically place the qualified bearing ring sample from step six in the fixture, tighten the bolts on both sides to clamp and fix it, turn on the power of the press to drive the punch head to move downward to compress the surface of the bearing ring, and test its compressive strength.

[0023] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for high-strength bearing rings, characterized in that, The specific production process steps are as follows: Step 1: Select the bearing ring production bar stock, inspect the bar stock, conduct trial operation of the production equipment, and provide technical instructions to the staff; Step 2: The bar stock is cold-drawn using a cold drawing machine to make the outer diameter of the bar stock the size required for the bearing ring. Then, the cold-drawn bar stock is axially drilled using a CNC lathe with the hole diameter being the inner diameter of the bearing ring. Finally, the bar stock is radially cut according to the required size to obtain the blank. Step 3: Before forging, the billet obtained in step 2 is subjected to induction heating treatment to improve its plasticity and reduce deformation resistance. The heated raw material is upsetting on a forging hammer to form a preliminary ring shape. The upset billet is extruded in a mold to form a ring semi-finished product that is closer to the final shape. Step 4: The processed semi-finished rings are subjected to constant temperature heat treatment at 800-950℃ for 80-130 minutes, followed by crystallization annealing with quenching medium for 50-80 minutes, and then unidirectional rolling for forming multiple times. The equivalent variable of each unidirectional rolling is 1.5-3. Step 5: Use a high-frequency heating furnace to heat the surface of the workpiece at the fastest possible heating speed, greater than 600℃ / second, to rapidly heat to 980℃~1100℃. Spray quenching medium onto the heated bearing ring surface for crystallization annealing for 80~100min. After holding at the temperature, cool with the furnace to 145~155℃, then open the furnace door to cool to room temperature. Step Six: After quenching, allow the semi-finished bearing rings to cool naturally. Then, use a plasma spray gun to spray a composite ceramic coating at high temperature. The plasma flow rate of H2 is 2.5L / min, the powder feeding speed is 20g / min, the Ar flow rate is 25L / min, the current is 400A, and the voltage is 50.5V, thereby manufacturing the finished bearing rings. Step 7: Use an industrial camera to photograph the outer surface of the formed bearing ring sample and transmit the image to a connected industrial computer. The industrial computer will then compare and analyze the images to inspect the appearance quality of the bearing ring. Step 8: The technicians use the PLC controller to set the working parameters of the press, place the bearing ring sample that passed the test in Step 7 vertically in the fixture, tighten the bolts on both sides to clamp and fix it, turn on the power of the press to drive the punch head to move downward to squeeze the surface of the bearing ring and test its compressive strength.

2. The high-strength bearing ring manufacturing process according to claim 1, characterized in that: In step one, the inspectors conduct production license testing on the bar stock. Enterprises that purchase imported bar stock that requires legal inspection should obtain a valid inspection certificate from the supplier. The bar stock can only be put into storage after the relevant indicators have been inspected and qualified.

3. The high-strength bearing ring manufacturing process according to claim 1, characterized in that: In step six, the bearing rings are pre-sandblasted before coating. The semi-finished bearing rings after sandblasting are ultrasonically cleaned with acetone, and then the surface of the semi-finished bearing rings is sandblasted with 24-mesh brown corundum abrasive.

4. The high-strength bearing ring manufacturing process according to claim 1, characterized in that: In step six, the composition ratio of chromium oxide, yttrium oxide, and aluminum oxide powders in the composite ceramic coating is: 80 wt.% chromium oxide powder, 10 wt.% yttrium oxide powder, and 10 wt.% aluminum oxide powder.

5. The high-strength bearing ring manufacturing process according to claim 4, characterized in that: The particle size of the chromium oxide, yttrium oxide, and aluminum oxide powder particles is 40μm to 50μm, and the thickness of the composite ceramic coating is 220μm to 280μm.

6. The high-strength bearing ring manufacturing process according to claim 1, characterized in that: In step five, the surface heating temperature must exceed the austenite region temperature range of 723℃ to 830℃.

7. The high-strength bearing ring manufacturing process according to claim 1, characterized in that: In step five, the quenching medium is one of water, aqueous solution, emulsion, or oily liquid.