Heat treatment process of high temperature alloy for CT machine ball bearing

Abstract

This invention discloses a heat treatment process for high-temperature alloys used in CT scanner X-ray tube bearings, comprising the following steps: S1, preparing GH2909 alloy material conforming to GB / T 14992 standard for pretreatment; S2, performing one solution treatment; S3, performing a first aging treatment; S4, performing a second aging treatment. This invention solves the problem that traditional dedicated heat treatment processes for GH2909 high-temperature alloys used in CT scanner X-ray tube bearings are insufficient to fully unleash the material's potential to meet the stringent requirements of CT scanner bearings under long-term high operating temperatures, load pressures, and complex alternating stresses.

Description

Technical Field

[0001] This invention relates to the field of bearing processing technology, specifically a heat treatment process for high-temperature alloys used in CT scanner ball tube bearings. Background Technology

[0002] As a key piece of equipment in medical diagnosis and industrial testing, the stability and accuracy of CT scanners directly depend on the performance of their core components. Among them, the CT scanner's X-ray tube bearing is the core component that supports the high-speed rotation of the X-ray tube and transmits the load. It needs to operate under harsh conditions of high operating temperature, continuous load pressure and complex alternating stress for a long time, which puts extremely high requirements on the high temperature strength, corrosion resistance, fatigue resistance and dimensional stability of the materials.

[0003] In the existing technology, GH2909 high-temperature alloy has become one of the preferred materials for manufacturing CT scanner tube bearings due to its excellent high-temperature mechanical properties, good corrosion resistance, and creep resistance. However, the final performance of high-temperature alloys is highly related to their heat treatment process. A suitable heat treatment process can fully stimulate the inherent potential of the material by controlling the grain size, precipitate type, distribution state, and residual stress of the alloy, so as to meet the service requirements of specific working conditions.

[0004] Currently, research on dedicated heat treatment processes for GH2909 high-temperature alloys specifically designed for CT scanner X-ray tube bearings is insufficient. Conventional heat treatment processes struggle to precisely match the stringent service requirements of CT scanner X-ray tube bearings, resulting in GH2909 high-temperature alloys failing to achieve optimal performance in terms of hardness, microstructure uniformity, and fatigue resistance after treatment, thus limiting their application in CT scanner X-ray tube bearings. Therefore, developing a targeted heat treatment process with precise parameters that fully leverages the potential of GH2909 high-temperature alloy is of significant practical value for improving the service life and operational reliability of CT scanner X-ray tube bearings, and has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a heat treatment process for high-temperature alloys used in CT scanner X-ray tube bearings. This process aims to solve the problem that traditional dedicated heat treatment processes for GH2909 high-temperature alloys used in CT scanner X-ray tube bearings are insufficient to fully unleash the material's potential and meet the stringent requirements of CT scanner bearings to withstand long-term high operating temperatures, load pressures, and complex alternating stresses.

[0006] To achieve the above objectives, the present invention provides a heat treatment process for high-temperature alloys used in CT scanner X-ray tube bearings, comprising the following steps: S1. Prepare GH2909 alloy material conforming to GB / T 14992 standard for pretreatment processing. The pretreatment processing is to heat the alloy material in a vacuum furnace to 600°C at a rate of 10°-20°C / min, hold it at that temperature for 20-30min, then heat it to 970-990°C at a rate of 10°-20°C / min, hold it at that temperature for 20-30min, and then perform a first gas quenching treatment. After the first gas quenching treatment, air cool it to room temperature. S2. The alloy material pretreated in step S1 is subjected to solution treatment. The solution treatment involves heating the alloy material in a vacuum furnace to 600°C at a rate of 10°-20°C / min, holding it at that temperature for 20-30 min, then heating it to 970°-990°C at a rate of 10°-20°C / min, holding it at that temperature for 50-70 min, and then performing a second gas quenching treatment. After the second gas quenching treatment, the material is air-cooled to room temperature. S3. The alloy material after solution treatment in step S2 is subjected to a first aging treatment. The first aging treatment involves heating the alloy material in the furnace to 710°-730°C at a rate of 10°-20°C / min, holding it at that temperature for 7-9 hours, and then furnace cooling it to 600-620°C at a rate of 50°C / h. S4. The alloy material after the first aging treatment in step S3 is subjected to a second aging treatment. The second aging treatment involves continuing to furnace cool the alloy material at a rate of 50°C / h to 610°-630°C, holding it at that temperature for 7-9 hours, and then rapidly cooling it to room temperature in the furnace.

[0007] The present invention further specifies that the first gas quenching cooling treatment is performed using argon gas cooling, with an inflation pressure of 2-5 bar and an inflation time of 1000-1400 s.

[0008] The present invention further specifies that the second gas quenching cooling process is performed using argon gas cooling, with an inflation pressure of 2-5 bar and an inflation time of 1000-1400 s.

[0009] The advantages of adopting the above technical solution are: the GH2909 alloy for CT scanner tube bearings processed by this process, through the precise synergy of pretreatment, solution treatment, and two aging treatments, combined with the controllable cooling method of argon gas quenching, achieves multiple core beneficial effects: firstly, it significantly improves the alloy hardness (≥340HB), forming... The optimized microstructure, characterized by uniformly dispersed strengthening phases and granular G phase (rich in Nb and Si phases) precipitation at grain boundaries, significantly enhances the material's high-temperature strength and corrosion resistance. Secondly, the stepped heating, holding, and slow furnace cooling process effectively eliminates residual stress, improving the alloy's fatigue resistance and dimensional stability, making it suitable for the harsh operating conditions of CT scanner X-ray tube bearings under long-term high temperatures, load pressures, and complex alternating stresses. Thirdly, the process parameters are precisely controllable (heating rate, holding time, gas quenching pressure, etc., are clearly quantified), with strong repeatability, which can stably stimulate the inherent potential of the GH2909 alloy and avoid performance fluctuations caused by conventional processes. Fourthly, the final processed alloy material can fully meet the core usage requirements of CT scanner X-ray tube bearings, extending bearing life and operational reliability, and providing key material support for the stable operation of CT equipment. Attached Figure Description

[0010] Figure 1 This is a heat treatment heating curve diagram of the present invention; Figure 2 This is a metallographic diagram of the GH2909 high-temperature alloy after heat treatment according to the present invention; Figure 3 This is a graph showing the hardness data of GH2909 high-temperature alloy after heat treatment according to the present invention. Detailed Implementation Specific implementation method one: S1. Take GH2909 high-temperature alloy material with specifications of 10mm×10mm×50mm and conforming to GB / T 14992 standard. Place the GH2909 high-temperature alloy sample into a vacuum heating furnace and heat it to 600℃ at a rate of 20℃ / min. Hold it at that temperature for 30min. Then heat it to 980℃ at a rate of 20℃ / min and hold it at that temperature for 20min. After that, cool it with argon gas at a pressure of 3bar for 1200s. After quenching with argon gas, air cool it to room temperature and remove it from the furnace. S2. Place the pretreated GH2909 high-temperature alloy sample into a vacuum heating furnace, heat it to 600℃ at a rate of 20℃ / min, hold it for 30min, then heat it to 900℃ at a rate of 20℃ / min, hold it for 60min, and then cool it with argon gas at a pressure of 3 bar for 1200s. After quenching, air cool it to room temperature and remove it from the furnace. S3. The solution-treated GH2909 high-temperature alloy material is heated to 710℃ in the furnace at a heating rate of 20℃ / min and held for 7 hours. S4. Based on the first aging treatment, cool the furnace to 610℃ at a rate of 50℃ / h, hold for 7 hours, and then rapidly cool to room temperature before removing from the furnace. Specific Implementation Method Two: S1. Take GH2909 high-temperature alloy material with specifications of 15mm×15mm×60mm and conforming to GB / T 14992 standard. Place the GH2909 high-temperature alloy sample into a vacuum heating furnace and heat it to 600℃ at a rate of 10℃ / min. Hold it at that temperature for 30min. Then heat it to 900℃ at a rate of 10℃ / min. Hold it at that temperature for 30min. Then cool it with argon gas. The gas pressure is 3bar and the gas filling time is 1200s. After gas quenching, air cool it to room temperature and take it out of the furnace. S2. Place the pretreated GH2909 high-temperature alloy sample into a vacuum heating furnace, heat it to 600℃ at a rate of 20℃ / min, hold it for 30min, then heat it to 900℃ at a rate of 20℃ / min, hold it for 70min, and then cool it with argon gas at a pressure of 3 bar for 1200s. After quenching, air cool it to room temperature and remove it from the furnace. S3. The solution-treated GH2909 high-temperature alloy material is first heated to 720℃ in the furnace at a heating rate of 10℃ / min, held for 8h, and then furnace cooled to 600℃ at a rate of 50℃ / h. S4. Based on the first aging treatment, cool the furnace to 620°C at a rate of 50°C / h, hold for 8 hours, and then rapidly cool the furnace to room temperature before removing from the furnace.

[0013] Final testing showed that the GH2909 high-temperature alloy material treated with this invention had a hardness >340HB. (See attached instruction manual.) Figure 3 The hardness data for GH2909 high-temperature alloy after the above heat treatment are provided. (See attached instruction manual.) Figure 2 The image shows the metallographic structure of the GH2909 high-temperature alloy after heat treatment according to the present invention. The structure is as follows: the γ' strengthening phase is uniformly dispersed in the austenite matrix, and granular G phase (rich in Nb and Si phase) appears at the grain boundaries.

[0014] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A heat treatment process for a high-temperature alloy used in CT scanner X-ray tube bearings, characterized in that: Includes the following steps: S1. Prepare GH2909 alloy material conforming to GB / T 14992 standard for pretreatment processing. The pretreatment processing is to heat the alloy material in a vacuum furnace to 600°C at a rate of 10°-20°C / min, hold it at that temperature for 20-30min, then heat it to 970-990°C at a rate of 10°-20°C / min, hold it at that temperature for 20-30min, and then perform a first gas quenching treatment. After the first gas quenching treatment, air cool it to room temperature. S2. The alloy material pretreated in step S1 is subjected to solution treatment. The solution treatment involves heating the alloy material in a vacuum furnace to 600°C at a rate of 10°-20°C / min, holding it at that temperature for 20-30 min, then heating it to 970°-990°C at a rate of 10°-20°C / min, holding it at that temperature for 50-70 min, and then performing a second gas quenching treatment. After the second gas quenching treatment, the material is air-cooled to room temperature. S3. The alloy material after solution treatment in step S2 is subjected to a first aging treatment. The first aging treatment involves heating the alloy material in the furnace to 710°-730°C at a rate of 10°-20°C / min, holding it at that temperature for 7-9 hours, and then furnace cooling it to 600-620°C at a rate of 50°C / h. S4. The alloy material after the first aging treatment in step S3 is subjected to a second aging treatment. The second aging treatment involves continuing to furnace cool the alloy material at a rate of 50°C / h to 610°-630°C, holding it at that temperature for 7-9 hours, and then rapidly cooling it to room temperature in the furnace.

2. The heat treatment process for a high-temperature alloy used in a CT scanner X-ray tube bearing according to claim 1, characterized in that: The first gas quenching cooling process uses argon gas for cooling, with an inflation pressure of 2-5 bar and an inflation time of 1000-1400 s.

3. The heat treatment process for a high-temperature alloy used in a CT scanner X-ray tube bearing according to claim 1, characterized in that: The second gas quenching cooling process uses argon gas for cooling, with an inflation pressure of 2-5 bar and an inflation time of 1000-1400 s.

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