Austenite-bainite ductile iron isothermal quenching method capable of prolonging service life of ADI casting

Abstract

The invention relates to the technical field of isothermal quenching, and provides an austempered ductile iron isothermal quenching method for prolonging the service life of an ADI casting, which comprises the following steps: collecting and measuring the thickness and surface area of the casting to be subjected to isothermal quenching, and carrying out preheating treatment, first heat preservation treatment, heating to austenitizing temperature treatment and second heat preservation treatment on the casting, the heat flow and the casting temperature are collected in the isothermal quenching process of the casting; marking a target acquisition moment and a prediction basis moment, determining a quenching heat release influence coefficient and a prediction weight of the target acquisition moment, and obtaining a casting temperature prediction value of a next adjacent acquisition moment of the target acquisition moment in combination with the casting temperature; and performing temperature compensation on isothermal quenching of the casting according to the temperature predicted value of the casting, and performing air cooling operation and cleaning on the casting subjected to isothermal quenching to finish isothermal quenching of the austempered ductile iron. According to the invention, the temperature compensation process of isothermal quenching can be ensured to be carried out stably.

Description

Technical Field

[0001] The present application relates to the technical field of austempering, and in particular to a method for austempering austempering ductile iron (ADI) for extending the life of ADI castings. Background Art

[0002] ADI is austempered ductile iron, also known as austempered ductile iron. Austempering of austempered ductile iron involves using a heat treatment process to transform inexpensive ductile iron into an austempered structure, achieving excellent combined strength and toughness. During the austempering process for preparing austempered ductile iron, high-precision temperature sensors such as thermocouples and infrared thermometers are typically used to monitor temperature data in real time to ensure casting accuracy. When the preheated casting is transferred to a molten salt bath, metal bath, or other isothermal quenching medium, significant temperature fluctuations typically occur. This means the quenching medium rapidly cools after stirring. Temperature compensation is typically performed on the quenching medium using simulated temperature fields or historical temperature change curves.

[0003] However, austempering is an exothermic process. The longer the austempering time, the higher the ambient temperature around the casting. This will cause changes in the amount of heat passing through the casting surface within the same quenching time, resulting in a deviation between the casting temperature simulated by the temperature field during the temperature compensation process and the actual casting temperature, affecting the stability of the casting's heating temperature and easily causing cracks in the prepared ADI casting and damage to its toughness. Summary of the Invention

[0004] This application provides a method for austempering austempering ductile iron (ADI) to extend the life of ADI castings. This method addresses the issue of a difference between the simulated temperature and the actual temperature of the casting during austempering temperature compensation, which results in substandard performance and quality of the prepared ADI castings. The technical solution employed is as follows: One embodiment of the present application provides a method for austempering austempering ductile iron to extend the life of ADI castings, the method comprising the following steps: The thickness and surface area of ​​the casting to be austempered are measured. The casting is preheated, held for the first time, heated to the austenitizing temperature, and held for the second time. The treated casting is then transferred to the quenching medium and austempered. The heat flow and casting temperature are collected at different sampling points during the austempering process. Record any collection time as the target collection time, determine the quenching heat release influence coefficient at each target collection time based on the thickness and surface area of ​​the casting, the heat flux at each collection time, and the duration of quenching, determine the prediction weight of the target collection time based on the difference between the quenching heat release influence coefficients at different collection times adjacent to the target collection time, and combine the casting temperatures at the target collection time and the casting temperatures at different collection times adjacent to the target collection time to obtain the predicted casting temperature at the collection time next adjacent to the target collection time; The austempering of the casting is temperature compensated according to the predicted value of the casting temperature, and the casting after austempering is air-cooled and cleaned to complete the austempering of the Austempering of the Austempering Ductile Iron.

[0005] Furthermore, the holding time for the first and second holding treatments of the casting is: The insulation time is set to 2 minutes for every millimeter of casting thickness.

[0006] Furthermore, the austenitizing temperature during the austenitizing treatment should be: Greater than or equal to 850°C and less than or equal to 950°C.

[0007] Furthermore, the quenching heat release influence coefficient at each target collection moment is determined based on the thickness and surface area of ​​the casting, the heat flow at each collection moment, and the duration of quenching, including the specific method of: Calculate the heat transfer coefficient at the target acquisition time based on the thickness and surface area of ​​the casting and the heat flux at the target acquisition time; The quenching heat release influence coefficient at the target collection time is determined based on the difference in heat transfer coefficient between the first collection time and the target collection time during austempering of the casting, the thickness of the casting, and the length of time the casting has been quenched at the target collection time.

[0008] Furthermore, the quenching heat release influence coefficient at the target collection time is determined based on the difference between the heat conductivity coefficient at the first collection time and the target collection time of the austempering of the casting, the thickness of the casting, and the length of time the casting has been quenched at the target collection time, including the specific method of: The difference between the thermal conductivity coefficient at the target acquisition time and the thermal conductivity coefficient at the first acquisition time of the austempering of the casting is recorded as the first difference at the target acquisition time; The ratio of the thickness of the casting to the quenching time of the casting at the target collection time is recorded as the first ratio at the target collection time; The positive correlation processing result of the first difference and the first ratio at the target acquisition time is recorded as the quenching heat release influence coefficient at the target acquisition time.

[0009] Furthermore, the prediction weight of the target acquisition time is determined based on the difference between the quenching heat release influence coefficients of different acquisition times adjacent to the target acquisition time, including the specific method of: Recording the first preset number of collection moments before the target collection moment as prediction basis moments of the target collection moment; Determining a second ratio of the target acquisition time according to the prediction basis time of the target acquisition time and the quenching heat release influence coefficient of the target acquisition time; The ratio of the number 2 to the time interval between adjacent collection moments is recorded as the third ratio of the target collection moment; The positive correlation processing result of the second ratio and the third ratio of the target collection time is recorded as the prediction weight of the target collection time.

[0010] Furthermore, the second ratio of the target acquisition time is determined based on the prediction basis time of the target acquisition time and the quenching heat release influence coefficient at the target acquisition time, including the specific method of: The cumulative sum of the prediction basis time of the target acquisition time and the quenching heat release influence coefficient at the target acquisition time is recorded as the total quenching heat release influence coefficient at the target acquisition time, and the ratio of the quenching heat release influence coefficient at the target acquisition time to the total quenching heat release influence coefficient is recorded as the second ratio at the target acquisition time.

[0011] Furthermore, the method for obtaining the casting temperature prediction value at the next adjacent collection time of the target collection time is: The prediction weight of the target acquisition time is used as the value of the smoothing coefficient. Data prediction is performed based on the casting temperature at the target acquisition time and all predictions based on the target acquisition time, and the casting temperature prediction value at the next adjacent acquisition time of the target acquisition time is obtained.

[0012] Furthermore, the temperature compensation for austempering of the casting according to the predicted value of the casting temperature includes the following specific methods: The casting temperature prediction value at the next adjacent collection time of the target collection time is used as the casting temperature at the next adjacent collection time of the target collection time, so that the temperature of the casting component during isothermal quenching is maintained at the preset target temperature, thereby realizing temperature compensation during the isothermal quenching process.

[0013] Furthermore, the air cooling and cleaning of the austempered castings may include the following specific methods: Air cool the casting to room temperature and remove the residual quenching medium from the casting.

[0014] The beneficial effects of this application are: In the process of isothermal quenching of castings, the present application evaluates the influence of quenching heat release on the castings at each sampling moment, obtains the quenching heat release influence coefficient at the target sampling moment, determines the prediction weight of the target sampling moment based on the difference between the quenching heat release influence coefficients at different sampling moments adjacent to the target sampling moment, and determines the contribution of different sampling moments adjacent to the target sampling moment and the casting temperature at the target sampling moment to the predicted value of the casting temperature at the next adjacent sampling moment of the target sampling moment based on the prediction weight, and at the same time, determines the next adjacent sampling moment of the target sampling moment. The predicted casting temperature at the moment of collection is collected; then, temperature compensation is performed on the austempering of the casting according to the predicted casting temperature, so that the temperature of the component of the austempering casting is maintained at the preset target temperature, ensuring the smooth progress of the austempering of the casting temperature, extending the life of the ADI casting, and solving the problem that the performance and quality of the prepared ADI castings do not meet the standards due to the difference between the simulated temperature and the actual temperature of the casting during the temperature compensation process of austempering, thereby improving the quality of the prepared ADI castings; finally, the castings that have completed austempering are air-cooled and cleaned to complete the austempering of the ADI. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 A schematic flow chart of a method for austempering austempering ductile iron to extend the life of ADI castings provided in one embodiment of the present application; Figure 2 A flowchart for obtaining the quenching heat release influence coefficient provided in one embodiment of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0018] See also Figure 1 , which shows a flow chart of a method for austempering austempering ductile iron to extend the life of ADI castings provided by one embodiment of the present application, the method comprising the following steps: Step S001: Collect and measure the thickness and surface area of ​​the casting to be austempered. The casting is sequentially subjected to preheating treatment, a first holding treatment, heating to an austenitizing temperature, and a second holding treatment. The treated casting is transferred to a quenching medium and austempered. During the austempering process, the heat flow and casting temperature of the casting are collected at different collection times.

[0019] Measure the thickness and surface area of ​​the casting to be austempered.

[0020] Armored thermocouples are fixed to the sides and center of the furnace. During the austempering process for producing ADI, they are used to collect real-time furnace temperatures. The range of the thermocouples must reach 1000°C to ensure accurate acquisition of furnace temperatures during the austenitization phase. Use high-temperature-resistant adhesive to connect the thermocouples to the temperature measurement area of ​​the casting. During the austempering process for producing ADI, they are used to collect casting temperatures. Insert the thermocouples into the slot at the inlet of the quenching medium, within 10 cm of the casting immersion point. During the austempering process for producing ADI, they are used to collect quenching medium temperatures.

[0021] In order to avoid the interference of electromagnetic noise on the temperature acquisition process, the furnace temperature, casting temperature and quenching medium temperature are denoised separately.

[0022] This embodiment uses wavelet threshold denoising to denoise the furnace temperature, casting temperature, and quenching medium temperature separately. As other implementations, while achieving the goal of denoising the furnace temperature, casting temperature, and quenching medium temperature separately, the implementer may use other existing methods such as Savitzky-Golay filtering and median filtering to denoise the furnace temperature, casting temperature, and quenching medium temperature separately. This application does not impose any special restrictions.

[0023] Before using austempering technology to prepare austempered ductile iron for castings, the castings must first be moved to a heating furnace for preheating. Preheating treatment is performed at a temperature below the austenitizing temperature. A PLC controller is used to control the heating rate and preheating temperature. In this embodiment, the heating rate is set to increase by 100°C per hour, and the preheating temperature is set to 600°C to avoid deformation or cracking of the castings due to thermal stress. The castings that have completed the preheating treatment are subjected to a first insulation treatment. The insulation time for the first insulation treatment is determined according to the thickness of the casting. Specifically, in this embodiment, the insulation time is set to 2 minutes per millimeter of thickness of the casting to ensure that the overall temperature of the casting is uniform and that the casting can undergo austenite transformation smoothly. The castings that have completed the insulation treatment are further heated to the austenitizing temperature. The austenitizing temperature is greater than or equal to 850°C and less than or equal to 950°C. In this embodiment, 900°C is selected as the austenitizing temperature. The casting, heated to the austenitizing temperature, undergoes a second holding treatment to ensure uniform temperature throughout the casting and complete transformation of the ferrite and pearlite into uniform, carbon-saturated austenite. The holding time is determined by the thickness of the casting; specifically, this embodiment sets a holding time of 2 minutes per millimeter of casting thickness. The casting is then quickly transferred to a quenching medium for austempering. In this embodiment, the quenching medium temperature is set at 300°C.

[0024] As other embodiments, on the basis of achieving the purpose of preheating, keeping warm and heating the casting to the austenitizing temperature, the implementer can set the preheating heating rate and preheating temperature, holding time, and austenitizing temperature by himself, and this application does not impose any special restrictions.

[0025] During the austempering process of the casting, the heat flow is collected by a heat flow meter.

[0026] During the isothermal quenching process of the casting, the heat flow is collected every 10 seconds.

[0027] At this point, the thickness and surface area of ​​the casting to be austempered, as well as the heat flow and casting temperature of the casting at different acquisition moments during the austempering process are obtained.

[0028] Step S002: Record any collection moment as the target collection moment. Determine the quenching heat release influence coefficient for each target collection moment based on the thickness and surface area of ​​the casting, the heat flux at each collection moment, and the duration of quenching. Determine the prediction weight for the target collection moment based on the difference between the quenching heat release influence coefficients at different collection moments adjacent to the target collection moment. Combine the casting temperatures at the target collection moment and the casting temperatures at different collection moments adjacent to the target collection moment to obtain a predicted casting temperature at the collection moment immediately adjacent to the target collection moment.

[0029] To extend the service life of ADI castings, the temperature must be maintained stable within the specified temperature range during austempering to avoid cracks and loss of toughness caused by excessive temperature fluctuations. Since the re-insulated casting remains at the austenitizing temperature, but the temperature of the quenching medium is significantly lower than the austenitizing temperature, both the casting and the quenching medium experience significant temperature fluctuations during the transfer of the casting into the quenching medium. To ensure the smooth progress of the austempering operation, the quenching medium temperature must be compensated using a simulated temperature field or historical temperature curve. As austempering progresses, since the quenching process is exothermic, the longer the austempering time, the higher the ambient temperature around the casting. This results in variations in the amount of heat passing through the casting surface during the same quenching time, leading to a deviation between the simulated temperature field and the actual casting temperature.

[0030] Any sampling time during the austempering process of the casting is recorded as the target sampling time.

[0031] The heat transfer coefficient at the target collection time is calculated based on the thickness and surface area of ​​the casting and the heat flux at the target collection time. The calculation of the heat transfer coefficient is a well-known technique and will not be described in detail here.

[0032] The same method can be used to obtain the heat transfer coefficient at each sampling moment during the austempering of the casting.

[0033] The difference between the thermal conductivity coefficient at the target acquisition time and the thermal conductivity coefficient at the first acquisition time of isothermal quenching of the casting is recorded as the first difference at the target acquisition time; the ratio of the thickness of the casting to the length of time the casting has been quenched at the target acquisition time is recorded as the first ratio at the target acquisition time; and the positive correlation processing result of the first difference at the target acquisition time and the first ratio is recorded as the quenching heat release influence coefficient at the target acquisition time.

[0034] It is understood that performing positive correlation processing on the first difference and the first ratio ensures that the first difference and the first ratio are respectively positively correlated with the quenching heat release influence coefficient. It is understood that in this application, a positive correlation refers to the relationship between an independent variable and a dependent variable, where the independent variables are the first difference and the first ratio, and the dependent variable is the quenching heat release influence coefficient. A positive correlation means that the dependent variable increases (decreases) as the independent variable increases (decreases), and can be an additive relationship, a multiplicative relationship, etc.

[0035] Preferably, as an embodiment of the present application, the calculation result of the exponential power with the natural constant as the base and the first difference at the target acquisition time as the exponent is recorded as the first exponential value at the target acquisition time, and the product of the first exponential value at the target acquisition time and the first ratio is recorded as the quenching heat release influence coefficient at the target acquisition time.

[0036] The quenching heat release influence coefficient is used to evaluate the influence of quenching heat release on the casting at the corresponding acquisition time. The quenching heat release influence coefficient acquisition flow chart is as follows: Figure 2 shown.

[0037] The adjacent Each collection moment is recorded as the prediction basis moment of the target collection moment.

[0038] in, represents a first preset number. In this embodiment, the value of the first preset number is 5. It can be understood that when the number of adjacent collection moments before the target collection moment is less than the first preset number, in order to ensure the accuracy of the temperature step at the target collection moment, the target collection moment is not analyzed.

[0039] The cumulative sum of the prediction basis time of the target acquisition time and the quenching heat release influence coefficient at the target acquisition time is recorded as the total quenching heat release influence coefficient at the target acquisition time, and the ratio of the quenching heat release influence coefficient at the target acquisition time to the total quenching heat release influence coefficient is recorded as the second ratio of the target acquisition time; the ratio of the number 2 to the time interval between adjacent acquisition times is recorded as the third ratio of the target acquisition time; the positive correlation processing result of the second ratio and the third ratio at the target acquisition time is recorded as the prediction weight of the target acquisition time.

[0040] In the process of calculating the ratio of the number 2 and the time interval between adjacent collection moments, in order to avoid the denominator being zero, a preset value needs to be added to the denominator. In an embodiment, the preset value is 1.

[0041] It is understood that the second ratio and the third ratio are positively correlated, that is, the second ratio and the third ratio are ensured to be positively correlated with the predicted weight. It is understood that the positive correlation in this application refers to the relationship between the independent variable and the dependent variable, the independent variable being the second ratio and the third ratio, and the dependent variable being the predicted weight. The positive correlation means that the dependent variable increases (decreases) as the independent variable increases (decreases), and can be an additive relationship, a multiplicative relationship, etc.

[0042] Preferably, as an embodiment of the present application, the product of the second ratio and the third ratio of the target collection time is recorded as the prediction weight of the target collection time.

[0043] The prediction weight of the target collection time is used as the value of the smoothing coefficient. The EMA exponentially weighted moving average algorithm is used to obtain the casting temperature prediction value at the next adjacent collection time of the target collection time based on the casting temperature at the target collection time and all prediction basis times of the target collection time.

[0044] Among them, using the EMA exponentially weighted moving average algorithm to obtain the predicted value is a well-known technology and will not be described in detail.

[0045] The same method can be used to obtain the casting temperature prediction value at the next adjacent sampling time of any sampling time during the isothermal quenching process of the casting.

[0046] Step S003: performing temperature compensation for austempering of the casting according to the predicted value of the casting temperature, air-cooling and cleaning the austempering casting, and completing the austempering of the Austempering of the Austempering Ductile Iron.

[0047] The predicted casting temperature at the next adjacent collection time after the target collection time is used as the casting temperature at the next adjacent collection time after the target collection time. The power of the resistance heater and the valve opening of the cooling valve are controlled by the PID control algorithm. Temperature compensation is performed on the austempering process to keep the temperature of the casting austempering component at the preset target temperature, ensuring smooth austempering of the casting temperature and extending the life of the ADI casting.

[0048] Among them, the target temperature maintained during austempering of the casting is determined by the parameter requirements of the ADI casting. Specifically, the target temperature of ADI castings with high toughness and low hardness is generally greater than or equal to 300°C and less than or equal to 400°C, and the target temperature of ADI castings with high strength and high wear resistance is generally greater than or equal to 220°C and less than or equal to 300°C; the power of the resistance heater and the valve opening of the cooling valve are controlled by the PID control algorithm to keep the temperature of the components of the austempering of the casting at the preset target temperature. The specific process is a well-known technology and will not be repeated here.

[0049] The duration of austempering of the casting is determined according to the thickness of the casting. Specifically, in this embodiment, the austempering time is set to 2 minutes per millimeter of thickness of the casting.

[0050] By precisely controlling the temperature and duration of austempering of castings, the microstructure of the casting material can be directional controlled, promoting the isothermal transformation of austenite to bainite. Depending on the parameter requirements of the ADI casting, the casting can be transformed into upper bainite with high toughness and low hardness, or into lower bainite with high strength and high wear resistance.

[0051] Take out the casting that has completed austempering and perform air cooling operation, cool the casting temperature to room temperature, and use hot water or special equipment to remove the residual quenching medium from the casting after the casting has cooled, completing the austempering operation of the Austempering Ductile Iron to extend the life of the casting.

[0052] At this point, the austempering of Austempering ductile iron is completed.

[0053] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for austempering ADI castings to extend the life of ADI castings, characterized in that: The method comprises the following steps: The thickness and surface area of ​​the casting to be austempered are measured. The casting is preheated, held for the first time, heated to the austenitizing temperature, and held for the second time. The treated casting is then transferred to the quenching medium and austempered. The heat flow and casting temperature are collected at different sampling points during the austempering process. Record any collection time as the target collection time, determine the quenching heat release influence coefficient at each target collection time based on the thickness and surface area of ​​the casting, the heat flux at each collection time, and the duration of quenching, determine the prediction weight of the target collection time based on the difference between the quenching heat release influence coefficients at different collection times adjacent to the target collection time, and combine the casting temperatures at the target collection time and the casting temperatures at different collection times adjacent to the target collection time to obtain the predicted casting temperature at the collection time next adjacent to the target collection time; The austempering of the casting is temperature compensated according to the predicted value of the casting temperature, and the casting after austempering is air-cooled and cleaned to complete the austempering of the Austempering of the Austempering Ductile Iron.

2. A method for austempering austempering ductile iron for extending the life of ADI castings according to claim 1, characterized in that: The holding time for the first and second holding treatments of the castings is: The insulation time is set to 2 minutes for every millimeter of casting thickness.

3. The austempering method for extending the life of ADI castings according to claim 1, characterized in that: The austenitizing temperature during the austenitizing treatment should be: Greater than or equal to 850°C and less than or equal to 950°C.

4. The austempering method for extending the life of ADI castings according to claim 1, characterized in that: The method of determining the quenching heat release influence coefficient at each target collection moment according to the thickness and surface area of ​​the casting, the heat flow at each collection moment, and the duration of quenching is as follows: Calculate the heat transfer coefficient at the target acquisition time based on the thickness and surface area of ​​the casting and the heat flux at the target acquisition time; The quenching heat release influence coefficient at the target collection time is determined based on the difference in heat transfer coefficient between the first collection time and the target collection time during austempering of the casting, the thickness of the casting, and the length of time the casting has been quenched at the target collection time.

5. A method for austempering ADI castings to extend the life of ADI castings according to claim 4, characterized in that: The method of determining the quenching heat release influence coefficient at the target collection time based on the difference between the heat conductivity coefficient at the first collection time and the target collection time of the austempering of the casting, the thickness of the casting, and the length of time the casting has been quenched at the target collection time includes the following specific methods: The difference between the thermal conductivity coefficient at the target acquisition time and the thermal conductivity coefficient at the first acquisition time of the austempering of the casting is recorded as the first difference at the target acquisition time; The ratio of the thickness of the casting to the quenching time of the casting at the target collection time is recorded as the first ratio at the target collection time; The positive correlation processing result of the first difference and the first ratio at the target acquisition time is recorded as the quenching heat release influence coefficient at the target acquisition time.

6. The austempering method for extending the life of ADI castings according to claim 1, characterized in that: The method of determining the prediction weight of the target acquisition time according to the difference between the quenching heat release influence coefficients of different acquisition times adjacent to the target acquisition time includes the following specific methods: Recording the first preset number of collection moments before the target collection moment as prediction basis moments of the target collection moment; Determining a second ratio of the target acquisition time according to the prediction basis time of the target acquisition time and the quenching heat release influence coefficient of the target acquisition time; The ratio of the number 2 to the time interval between adjacent collection moments is recorded as the third ratio of the target collection moment; The positive correlation processing result of the second ratio and the third ratio of the target collection time is recorded as the prediction weight of the target collection time.

7. A method for austempering ADI castings to extend the life of ADI castings according to claim 6, characterized in that: The method of determining the second ratio of the target acquisition time according to the prediction basis time of the target acquisition time and the quenching heat release influence coefficient at the target acquisition time includes the following specific methods: The cumulative sum of the prediction basis time of the target acquisition time and the quenching heat release influence coefficient at the target acquisition time is recorded as the total quenching heat release influence coefficient at the target acquisition time, and the ratio of the quenching heat release influence coefficient at the target acquisition time to the total quenching heat release influence coefficient is recorded as the second ratio at the target acquisition time.

8. The austempering method for extending the life of ADI castings according to claim 1, characterized in that: The method for obtaining the casting temperature prediction value at the next adjacent collection time of the target collection time is: The prediction weight of the target acquisition time is used as the value of the smoothing coefficient. Data prediction is performed based on the casting temperature at the target acquisition time and all predictions based on the target acquisition time, and the casting temperature prediction value at the next adjacent acquisition time of the target acquisition time is obtained.

9. The austempering method for austempering ADI castings for extending the life of ADI castings according to claim 1, characterized in that: The specific method of performing temperature compensation for austempering of castings according to the predicted value of casting temperature is as follows: The casting temperature prediction value at the next adjacent collection time of the target collection time is used as the casting temperature at the next adjacent collection time of the target collection time, so that the temperature of the casting component during isothermal quenching is maintained at the preset target temperature, thereby realizing temperature compensation during the isothermal quenching process.

10. The austempering method for austempering ADI castings to extend the life of ADI castings according to claim 1, characterized in that: The specific method of air cooling and cleaning the austempered castings includes: Air cool the casting to room temperature and remove the residual quenching medium from the casting.

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