Rapid solid solution and rapid starting from high-temperature variable-temperature alternating aging heat treatment method

[0055] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be more thoroughly understood, and will fully convey the scope of the present disclosure to those skilled in the art.

[0056] like figure 2 As shown, an embodiment of the present invention proposes a rapid solution heat treatment method and a rapid starting high temperature alternating aging heat treatment method, comprising: step 21, rapid solution heat treatment process; and step 22, rapid starting high temperature alternating aging heat treatment process.

[0057] The process of the method is as follows: firstly, a first part of rapid solid solution heat treatment is performed, and finally, a second part of rapid and alternating aging heat treatment starting from high temperature and variable temperature is performed.

[0058] The first part of the rapid solution heat treatment process: relying on the first part of the rapid solution heat treatment process: including heating and heat preservation when the austenitic stainless steel is heated from room temperature to the highest temperature of rapid solution in a heating furnace within a specified time, Continue the heating and heat preservation of the austenitic stainless steel from the highest temperature of rapid solution solution to the intermediate solution temperature of rapid solution, and then continue to cool the austenitic stainless steel from the intermediate solution temperature of rapid solution to the lowest temperature of rapid solution The heating and heat preservation at high temperature, and finally the rapid solution heat treatment process consisting of cooling and other steps when the austenitic stainless steel is released from the furnace by a specific cooling method, which is cooled from the lowest temperature of rapid solution solution to room temperature;

[0059] The second part rapidly starts the high-temperature variable-temperature alternating aging heat treatment process: that is, after the first part of the rapid solution heat treatment is completed, the second part of the rapid-start high-temperature variable-temperature alternating aging heat treatment is continued, relying on the rapid starting high-temperature variable-temperature alternating aging process. Aging heat treatment process, including the first rapid starting from high temperature and finally high temperature alternating aging process: first, the first half of the first half of the rapid starting from high temperature and ending at low temperature without alternating aging process: that is, the austenitic stainless steel is firstly treated within a specified time. In the heating furnace, the heating and heat preservation at the highest aging temperature is carried out when the temperature is raised from room temperature to the highest temperature of aging, and then the heating and heat preservation at the intermediate temperature of aging carried out when the austenitic stainless steel is cooled to the intermediate temperature of aging is continued. The minimum aging temperature heating and heat preservation performed when the austenitic stainless steel is cooled to the final minimum aging temperature;

[0060] Then continue the first and second part of the alternating aging process starting from low temperature and ending at high temperature: that is, the aging process when the austenitic stainless steel is heated from the lowest aging temperature to the middle aging temperature in the heating furnace within a specified time. Intermediate temperature heating and heat preservation, and then continue to heat the austenitic stainless steel from the aging intermediate temperature to the aging maximum temperature in the heating furnace within the specified time. The alternating aging process is all over); after the above first rapid starting from high temperature and finally high temperature and variable temperature alternating aging process, continue to carry out the 2nd, 3rd, ..., Nth rapid alternating aging process: the first 2 times of rapid alternating aging, repeating the first time in reverse order, the second part of rapid starting from low temperature and finally high temperature alternating aging process 1 time (the second time rapidly starting from high temperature and finally ending at low temperature alternating aging process), the third time Rapid alternating aging, repeat the second rapid alternating aging process in reverse order for one time (the third rapid starting from low temperature and finally high temperature alternating aging process ends), ..., and so on, the Nth rapid alternating aging process Aging, repeat the N-1th rapid alternating aging process in reverse order (the Nth time rapidly starts from high temperature and ends at low temperature or starts from low temperature quickly and ends at high temperature and ends at the end of the alternating aging process); 3 times, ..., the Nth time, starting from a high temperature and ending at a low temperature or starting from a low temperature and ending at a high temperature, and then continuing the final cooling process after the alternating aging process ends: Finally, continue to use a specific cooling method to change the temperature of the austenitic stainless steel from the above. The process of cooling and other steps when the maximum or minimum temperature of the alternating aging is lowered to room temperature quickly begins with the high-temperature alternating-aging heat treatment process.

[0061] In the embodiment of the present invention, the first part of the rapid solution heat treatment method is carried out under the conditions of multi-stage heating temperature range, multi-stage heating sequence, multi-stage heating time, multi-stage heating times, specific cooling method, etc. Rapid solution heat treatment method.

[0062] In the embodiment of the present invention, the total solution times of the first part of the rapid solution heat treatment is 1 time.

[0063] In the embodiment of the present invention, the first part of the rapid solution heat treatment method is divided into a 3-stage rapid solution heat treatment method or a 4-stage rapid solution heat treatment method.

[0064] In the embodiment of the present invention, the multi-stage temperature range of the three-stage rapid solution heat treatment in the first part refers to: starting from the stage of heating up from room temperature to the highest temperature Tsfmax of solid solution, then cooling down to the stage of intermediate solution temperature Tsfm, and finally Cooling down to the minimum temperature of solid solution Tsfmin stage ends the three-stage cooling and heating temperature range.

[0065] In the embodiment of the present invention, the multi-stage temperature range of the four-stage rapid solid solution heat treatment in the first part refers to: starting from the stage of heating up from room temperature to the highest temperature Tsfmax of solid solution, and then cooling down to the first stage of intermediate solid solution in turn Temperature Tsfm 1 and the second stage temperature Tsfm of the intermediate solution 2 , and finally cool down to the 4-stage cooling and heating temperature range at the end of the minimum solid solution temperature Tsfmin stage.

[0066] In the embodiment of the present invention, the first part of the rapid solution heat treatment has a multi-stage temperature range, and the number of stages in the rapid solution heating temperature range should be moderate: the rapid solution heating temperature range is narrow (the effective temperature range is between 100°C and 200°C). ℃), if the number of stages in the solid solution heating temperature range is 1 stage, the solid solution ability is too poor (this is the existing solid solution technology), the solid solution ability is good for 2 stages, and the solid solution ability is ≥ 6 stages. Therefore, in this embodiment, the first part of the solid solution temperature stage interval is set to 3 stages or 4 stages, which can greatly improve the solid solution ability, quality and efficiency, especially can greatly increase the solid solution strengthening phase, reduce or Inhibit solid solution weakened phase, reduce high temperature heating time, improve efficiency and improve the service life of high temperature components of heating equipment.

[0067] In the embodiment of the present invention, the mathematical relationship between the minimum heating temperature Tsfmin of rapid solid solution and the minimum theoretical heating temperature Tsftmin of solid solution is: Tsfmin=Tsftmin;

[0068] where Tsfmin is the minimum heating temperature for rapid solid solution, °C; Tsftmin is the minimum theoretical heating temperature for rapid solid solution, °C.

[0069] In the embodiment of the present invention, the mathematical relationship between the maximum heating temperature Tsfmax of rapid solid solution and the maximum theoretical heating temperature Tsftmax of solid solution is: Tsfmax=Tsftmax;

[0070] where Tsfmax is the maximum heating temperature for rapid solid solution, °C; Tsftmax is the maximum theoretical heating temperature for rapid solid solution, °C.

[0071] In the embodiment of the present invention, the mathematical relationship between the three-stage rapid solid solution intermediate solution heating temperature Tsfm, the highest solid solution heating temperature Tsfmax and the lowest solid solution heating temperature Tsfmin is:

[0072] Tsfm=(Tsfmax+Tsfmin)/2

[0073] In the formula, Tsfm is the heating temperature in the intermediate solid solution stage of rapid solid solution, °C, which is also the heating temperature of the second stage of rapid solid solution; Tsfmax is the maximum heating temperature of rapid solid solution, °C, which is also the heating temperature in the initial stage of rapid solid solution; Tsfmin is The minimum heating temperature of rapid solid solution, ℃, is also the heating temperature of the final stage of rapid solid solution.

[0074] In the embodiment of the present invention, the heating temperature Tsfm of the first stage of the 4-stage rapid solid solution and the intermediate solid solution 1 and intermediate solution second stage heating temperature Tsfm 2 The mathematical relationship with the highest heating temperature Tsfmax of solid solution and the lowest heating temperature Tsfmin of solid solution are:

[0075] Tsfm 1 =2/3(Tsfmax–Tsfmin)+Tsfmin

[0076] Tsfm 2 =1/3(Tsfmax–Tsfmin)+Tsfmin

[0077] where Tsfm 1 is the heating temperature of the first stage of rapid solid solution, ℃, and also the heating temperature of the second stage of rapid solid solution; Tsfm 2 is the heating temperature of the second stage of rapid solid solution, ℃, and is also the heating temperature of the third stage of rapid solid solution; Tsfmax is the maximum heating temperature of rapid solid solution, ℃, and is also the heating temperature of the initial stage of rapid solid solution; Tsfmin is The minimum heating temperature of rapid solid solution, ℃, is also the heating temperature of the final stage of rapid solid solution.

[0078] In the embodiment of the present invention, the first part of the rapid solid solution multi-stage time interval corresponding to the rapid solid solution multi-stage temperature interval is also set to 3 stages or 4 stages; the rapid solid solution time should neither be too long nor too short : If the solid solution is too long, it will exceed the solubility limit of the strengthening phase, and if it is too short, the solid solution strengthening phase will not be dissolved rapidly. Therefore, setting the rapid solid solution time to a moderate value can also greatly improve the solid solution ability and quality. and efficiency, etc.

[0079] In the embodiment of the present invention, when the rapid solution time is carried out according to the equal time method, the total time τ of the multi-stage rapid solution heating of the equal time method sfN Heating time τ in each stage with rapid solid solution sfn The mathematical relationship is: τ sfN =∑τ sfn =∑τ sfN /N;

[0080] where τ sfN is the total time of multi-stage rapid solution heating of equal time method, min or h; τ sfn Heating time for each stage of rapid solid solution, min or h, when τ sf1 , τ sf2 , τ sf3 When there are three stages of time, τ sf1 =τ sf2 =τ sf3 , when the minute τ sf1 , τ sf2 , τ sf3 , τ sf4 When there are 4 stages in total, τ sf1 =τ sf2 =τ sf3 =τ sf4; N is the total number of stages of rapid solution heating, N=3 or 4; n is the nth stage number of rapid solution heating, n=1, 2, 3 or 4.

[0081] In the embodiment of the present invention, when the rapid solution time is carried out according to the incremental time method, the total time τ of the multi-stage rapid solution heating of the incremental time method sfN Heating time τ in each stage with rapid solid solution sfn The mathematical relationship is: τ sfN =∑τ sfn =∑[τ sf1 +(n–1)τ sf0 ];

[0082] where τ sfN is the total time of multi-stage rapid solution heating of the incremental time method, min or h; N is the total number of stages of rapid solution heating, N=3 or 4; τ sfn Heating time for each stage of rapid solid solution, min or h, divided into τ sf1 , τ sf2 , τ sf3 or τ sf4 , τ sf1τ sf2τ sf3 or >τ sf4; n is the nth stage number of rapid solution heating, n=1, 2, 3 or 4; τ sf1 Heating time for the first stage of rapid solid solution, min or h; τ sf0 It is the time difference of rapid solution heating decreasing time, min or h, which is the same and constant specific value.

[0083] In the embodiment of the present invention, when the rapid solution time is carried out according to the decreasing time method, the total time τ of the multi-stage rapid solution heating of the decreasing time method sfN Heating time τ in each stage with rapid solid solution sfn The mathematical relationship is: τ sfN =∑τ sfn =∑[τ sf1 –(n–1)τ sf0 ];

[0084] where τ sfN is the total time of multi-stage rapid solution heating by decreasing time method, min or h; N is the total number of stages of rapid solution heating, N=3 or 4; τ sfn Heating time for each stage of rapid solid solution, min or h, divided into τ sf1 , τ sf2 , τ sf3 or τ sf4 , τ sf1 sf2 sf3 or sf4;τ sf1 is the heating time of the first stage of rapid solution heating, min or h; n is the number of the nth stage of rapid solution heating, n=1, 2, 3 or 4; τ sf0 It is the time difference of rapid solution heating decreasing time, min or h, which is the same and constant specific value.

[0085] In the embodiment of the present invention, the final cooling method of the first part of the rapid solution heat treatment is: cooling in room temperature water.

[0086] In an embodiment of the present invention, the first part of the three-stage rapid solution heat treatment process is:

[0087] The first stage: the austenitic stainless steel is heated from room temperature to the minimum temperature Tsfmin of rapid solid solution in the heating furnace (and heated and kept warm within the time specified by the process);

[0088] The second stage: continue to heat the austenitic stainless steel from the lowest temperature Tsfmin of rapid solution solution to the intermediate solution temperature Tsfm (and heat and heat preservation within the time specified by the process);

[0089] The third stage: continue to heat the austenitic stainless steel from the rapid solid solution intermediate solution temperature Tsfm to the rapid solid solution maximum temperature Tsfmax (and heat and heat preservation within the time specified by the process);

[0090] Finally, a specific cooling method is continued to cool the austenitic stainless steel from the maximum temperature Tsfmax of rapid solution solution to room temperature (and heating and heat preservation within the time specified by the process).

[0091] In an embodiment of the present invention, the first part of the four-stage rapid solution heat treatment process is:

[0092] The first stage: the austenitic stainless steel is heated from room temperature to the minimum temperature Tsfmin of rapid solid solution in the heating furnace (and heated and kept warm within the time specified by the process);

[0093] The second stage: continue to heat the austenitic stainless steel from the lowest temperature of rapid solid solution Tsfmin to the first stage temperature of rapid solid solution intermediate solution Tsfm 1 (and heating and heat preservation within the time specified by the process);

[0094] The third stage: Continue to dissolve the austenitic stainless steel from the rapid solid solution to the first stage temperature Tsfm 1 Warm up to the second stage temperature Tsfm of rapid solid solution and intermediate solid solution 2 (and heating and heat preservation within the time specified by the process);

[0095] The fourth stage: continue the austenitic stainless steel from the rapid solid solution to the second stage temperature Tsfm 2 Heat up to the maximum temperature Tsfmax of rapid solid solution (and heat and keep warm within the time specified by the process);

[0096] Finally, a specific cooling method is continued to cool the austenitic stainless steel from the maximum temperature Tsfmax of rapid solution solution to room temperature (and heating and heat preservation within the time specified by the process).

[0097] In the embodiment of the present invention, the second part starts from the high temperature variable temperature alternating aging heat treatment method: after the first part of the rapid solution heat treatment is completed, it continues in the multi-stage heating temperature range, the multi-stage heating sequence, and the multi-stage heating Under the conditions of time, multi-stage heating times, specific cooling methods, etc., it starts from high temperature and variable temperature alternating aging heat treatment method.

[0098] In the embodiment of the present invention, the total number of times of alternating aging at variable temperature for the second part of the heat treatment at high temperature and finally at low temperature is one time, and one time includes 2≤N≤6 fractions, N= 2, or 3, 4, or 5, 6, and finally end the variable-temperature alternating aging process with N=2, 4 or 6 points (each variable-temperature alternating aging process should include at least 1 cooling and 1 heating at the same time) The rapidity starts from the high temperature and variable temperature alternating aging process).

[0099] In the embodiment of the present invention, the total number of times of alternating aging at high temperature for the second part of the heat treatment at high temperature and finally at high temperature alternating aging is 1 time, and one time includes 1≤N≤5 fractions, N= 1, or 2, 3, or 4, 5, and finally end the variable-temperature alternating aging process with N=1, 3 or 5 points (each variable-temperature alternating aging process should include at least 1 cooling and 1 heating at the same time) The rapidity starts from the high temperature and variable temperature alternating aging process).

[0100] In the embodiment of the present invention, the multi-stage cooling temperature interval involved in the second part rapidly starting from the high temperature variable temperature alternating aging refers to: the first cooling variable temperature alternating aging temperature interval: from the cooling aging maximum temperature interval Tafmax (marked as: Tafmax-1) starts, then passes through n-2 intermediate temperature intervals of aging Tafm (marked as: Tafm-1), and finally reaches the end of the minimum temperature interval of aging Tafmin (marked as: Tafmin-1) Staged (3≤n≤7, i.e. n=3, 4, 5, 6 or 7) cooling temperature range; 2nd, 3rd or 4th time cooling and changing temperature alternating aging temperature range: repeat the above cooling in sequence In the aging process, the relationship between the first, second, third and fourth cooling and changing temperature alternating aging minimum temperature interval values ​​is: Tafmin-1>Tafmin-2>Tafmin-3>Tafmin-4, the first The relationship between the values ​​in the intermediate temperature interval of the second, second, third, and fourth cooling and alternating aging is: Tafm-1>Tafm-2>Tafm-3>Tafm-4, the first and second times , the relationship between the values ​​of the maximum temperature interval of the 3rd and 4th time cooling and changing temperature alternating aging is: Tafmax-1>Tafmax-2>Tafmax-3>Tafmax-4; the second part starts rapidly from high temperature changing temperature alternating The multi-stage cooling temperature range involved in aging does not repeat any of the lowest temperature range of cooling and aging, the middle temperature range of cooling and aging and the highest temperature range of cooling and aging, nor any of the lowest temperature range of heating and aging, the middle temperature range of heating and aging and the The maximum temperature range of heating and aging.

[0101] In the embodiment of the present invention, the multi-stage heating temperature interval involved in the second part rapidly starting from the high temperature variable temperature alternating aging refers to: the first heating variable temperature alternating aging temperature interval: from the temperature rising and aging lowest temperature interval Tafmin (marked as: Tafmin-1) starts, then passes through n-2 intermediate temperature intervals of aging Tafm (marked as: Tafm-1), and finally reaches the end of the maximum aging temperature interval Tafmax (marked as: Tafmax-1) Staged (3≤n≤7, i.e. n=3, 4, 5, 6 or 7) heating temperature range; the 2nd, 3rd or 4th heating and variable temperature alternating aging temperature range: repeat the above heating in sequence In the aging process, the relationship between the first, second, third, and fourth heating and variable temperature alternating aging minimum temperature interval values ​​is: Tafmin-1>Tafmin-2>Tafmin-3>Tafmin-4, the first The relationship between the values ​​of the intermediate temperature interval of the second, second, third and fourth heating and aging is: Tafm-1>Tafm-2>Tafm-3>Tafm-4, the first, second, third The relationship between the values ​​of the maximum temperature interval of the second and fourth heating and variable temperature alternating aging is: Tafmax-1>Tafmax-2>Tafmax-3>Tafmax-4; the second part starts rapidly from the high temperature variable temperature alternating aging The multi-stage heating temperature range does not repeat any of the lowest temperature range of heating and aging, the middle temperature range of heating and aging and the highest temperature range of heating and aging, nor any of the lowest temperature range of cooling and aging, the middle temperature range of cooling and aging and the highest temperature range of cooling and aging. temperature range.

[0102]In the embodiment of the present invention, due to the narrow aging temperature range of austenitic stainless steel (between 170°C and 230°C), the alternating aging temperature range that rapidly starts from high temperature and variable temperature should neither be too small nor too much: 1 The stage aging temperature range belongs to the existing technology (no temperature difference), and the aging ability is too poor; when it is in the 2-stage aging temperature range (the temperature difference is large), the aging ability is increased but still insufficient; it is a ≥8 stage aging temperature range When the temperature difference is too small, the aging ability is excessive (in fact, each temperature rise or cooling transition stage still has a certain aging ability). Therefore, setting the temperature range of fast-starting high-temperature variable-temperature alternating aging to 3≤n≤7, that is, n=3, 4, 5, 6 or 7 stages, can be more conducive to improving the aging ability, range, quality and efficiency, etc. .

[0103] In the embodiment of the present invention, the mathematical relationship between the lowest heating temperature Tafmin and the lowest theoretical aging heating temperature Taftmin starting from high temperature variable temperature alternating aging rapidly is: Tafmin=Taftmin;

[0104] In the formula, Tafmin is the minimum heating temperature that starts rapidly from high temperature and alternating aging, ℃; Taftmin is the minimum theoretical heating temperature of aging, ℃.

[0105] In the embodiment of the present invention, the mathematical relationship between the maximum heating temperature Tafmax and the maximum theoretical heating temperature Taftmax starting from high temperature variable temperature alternating aging rapidly is: Tafmax=Taftmax;

[0106] In the formula, Tafmin is the maximum heating temperature that starts rapidly from high temperature and variable temperature and alternating aging, °C; Taftmin is the maximum theoretical heating temperature of aging, °C.

[0107] In the embodiment of the present invention, the mathematical relationship between the intermediate heating temperature Tafm, the minimum aging temperature Tafmin and the maximum aging heating temperature Tafmax in each stage of the second part of rapid temperature-change alternating aging is: Tafm=Tafmin+n i (Tafmax–Tafmin)/(n–1);

[0108] In the formula, Tafm is the intermediate heating temperature that starts rapidly at each stage of high-temperature variable-temperature alternating aging, °C, and is also the specific stage temperature from the second stage to the penultimate second stage of cooling or temperature-changing alternating aging; Tafmin is the temperature of cooling or heating The lowest temperature of variable temperature alternating aging, °C, is also the heating temperature of the last stage or the first stage of cooling or heating variable temperature alternating aging; n i It is the specific nth heating temperature interval from the second stage to the penultimate second stage from high to low or from low to high i Number of stages, 1≤n i ≤5, i.e. n i = 1, 2, 3, 4 or 5; Tafmax is the maximum heating temperature of cooling or heating-changing temperature alternating aging, ℃, also the heating temperature of the first stage or the last stage of cooling or heating-changing temperature alternating aging; (Tafmax–Tafmin )/n is the temperature gradient of decreasing or increasing temperature in cooling or heating, ℃, which is a constant specific value; n is the maximum heating temperature Tafmax interval starting from cooling and changing temperature, and finally the lowest heating temperature Tafmin or starting from heating The total number of stages in the interval of the lowest temperature Tafmin of variable temperature alternating aging and finally the maximum heating temperature of variable temperature alternating aging Tafmax, 3≤n≤7, that is, n=3, 4, 5, 6 or 7.

[0109] In the embodiment of the present invention, the total time of the rapid-start high-temperature variable-temperature alternating aging can neither be too short nor too long: when it is too short, the alloy element strengthening phase can only achieve limited aging precipitation capacity, quality and efficiency, etc. ; When it is too long, the aging ability, quality and efficiency of the alloy element strengthening phase will reach saturation or limit state.

[0110] In the embodiment of the present invention, when the fast-starting high-temperature variable-temperature alternating aging time is performed according to the equal-time method, the fast-starting high-temperature variable-temperature alternating aging heating total time τ of the equal-time method afN The heating time τ of each stage of aging corresponding to the heating temperature interval of the first stage, the second stage, the third stage, ... and the nth stage afn The mathematical relationship is: τ afN =∑τ afn =∑τ afN /N;

[0111] where τ afN It is the total time for the rapid start of high temperature variable temperature alternating aging heating of the equal time method, min or h; τ afn In order to quickly start the heating time of each stage of the aging corresponding to the heating temperature interval of the first stage, the second stage, the third stage, ..., the nth stage, min/time or h/time , respectively τ af1 , τ af2 , τ af3 , τ af4 , τ af5 , τ af6 or τ af7 , τ af1 =τ af2 =τ af3 =τ af4 =τ af5 =τ af6 or = τ af7; N is the total number of stages rapidly starting from high temperature variable temperature alternating aging heating, 3≤N≤7 (ie N=3, 4, 5, 6 or 7); n is the first stage rapidly starting high temperature variable temperature alternating aging heating n number of stages, 1≤n≤7 (ie n=1, 2, 3, 4, 5, 6 or 7).

[0112] In the embodiment of the present invention, when the rapid starting high temperature variable temperature alternating aging time is performed according to the incremental time method, the rapid starting high temperature variable temperature alternating aging heating total time τ of the incremental time method afN The heating time τ of each stage of aging corresponding to the heating temperature interval of the first stage, the second stage, the third stage, ... and the nth stage afn The mathematical relationship is: τ afN =∑τ afn =∑[τ af1 +(n–1)τ af0 ];

[0113] where τ afN is the total time of the rapid starting high temperature variable temperature alternating aging heating of the incremental time method, min or h; N is the total number of stages of rapid starting high temperature variable temperature alternating aging heating, 3≤N≤7 (that is, N=3, 4, 5, 6 or 7); τ afn In order to quickly start each stage of high temperature and variable temperature alternating aging, the heating time is min/time or h/time, respectively τ af1 , τ af2 , τ af3 , τ af4 , τ af5 , τ af6 , τ af7 , τ af1τ af2τ af3τ af4τ af5τ af6τ af7; n is the number of the nth stage rapidly starting from high temperature variable temperature alternating aging heating, 1≤n≤7 (ie n=1, 2, 3, 4, 5, 6 or 7); τ af1 In order to quickly start the first stage heating time of high temperature variable temperature alternating aging, min/time or h/time; τ af0 In order to rapidly start from high temperature, variable temperature and alternating aging heating time, the incremental difference, min/time or h/time, is the same specific value.

[0114] In the embodiment of the present invention, when the rapid starting high temperature variable temperature alternating aging time is performed according to the decreasing time method, the rapid starting high temperature variable temperature alternating aging heating total time τ of the decreasing time method afN The heating time τ of each stage of aging corresponding to the heating temperature interval of the first stage, the second stage, the third stage, ... and the nth stage afn The mathematical relationship is: τ afN =∑τ afn =∑[τ af1 –(n–1)τ af0 ];

[0115] where τ sfN It is the total time of rapid starting high temperature alternating aging heating with decreasing time method, min/time or h/time; N is the total number of stages rapidly starting high temperature alternating aging heating, 3≤N≤7 (that is, N= 3, 4, 5, 6 or 7); τ afn In order to quickly start the heating time of each stage of the aging corresponding to the heating temperature interval of the first stage, the second stage, the third stage, ..., the nth stage, min/time or h/time , respectively τ af1 , τ af2 , τ af3 , τ af4 , τ af5 , τ af6 , τ af7 , τ af1 af2 af3 af4 af5 af6 af7; n is the number of the nth stage rapidly starting from high temperature variable temperature alternating aging heating, 1≤n≤7 (ie n=1, 2, 3, 4, 5, 6 or 7); τ af1 In order to quickly start from the first stage of high temperature and variable temperature alternating aging, the heating time is min/time or h/time; τ af0 In order to rapidly start from high temperature, variable temperature and alternating aging heating, the time difference of decreasing time, min/time or h/time, is the same specific value.

[0116] In the embodiment of the present invention, the second part starts from the high temperature variable temperature alternating aging heat treatment and the final cooling method is: cooling in room temperature air.

[0117] In the embodiment of the present invention, the second part rapidly starts from the high temperature variable temperature alternating aging heat treatment, including the following process: the first rapid start from high temperature and finally the high temperature variable temperature alternating aging process: firstly, the first half of the rapid heat treatment is performed. Starting from high temperature and ending at low temperature without variable temperature alternating aging process: firstly, the austenitic stainless steel is heated and maintained at a medium speed from room temperature to the highest aging temperature in the heating furnace within a specified time, and then the austenitic stainless steel is rapidly cooled down. Heating and heat preservation to the intermediate temperature of aging, and then continue to rapidly cool the austenitic stainless steel to the lowest temperature of final aging for heating and heat preservation; That is, continue to rapidly heat the austenitic stainless steel from the lowest aging temperature to the intermediate aging temperature in the heating furnace within the specified time for heating and heat preservation, and then continue to rapidly heat the austenitic stainless steel from the aging intermediate temperature in the heating furnace within the specified time. Heating and heat preservation are carried out to the highest aging temperature (the first time rapidly starting from high temperature and finally high temperature variable temperature alternating aging process is completed); after the above first rapid start high temperature and high temperature variable temperature alternating aging process, continue after the second time. The second, third, ..., and N times of rapid temperature-changing alternating aging process: the second rapid temperature-changing and alternating aging process, and the reverse is repeated in turn for the second half of the first time, starting from low temperature and finally high-temperature alternating aging process 1 (the 2nd time starts at a high temperature and ends at a low temperature and the alternating aging process ends), or the 3rd rapid temperature change and alternating aging process, repeat the second rapid temperature change and alternating aging process in reverse order (the 3rd rapid temperature change and alternating aging process) At the low temperature and finally the high temperature changing temperature alternating aging process ends), ..., and so on, the Nth rapid temperature changing alternating aging process, and the N-1 rapid temperature changing alternating aging process is repeated in reverse order for 1 time (the Nth rapid temperature changing alternating aging process is repeated 1 time). Starting from high temperature and ending at low temperature or rapidly starting from low temperature and ending at high temperature and changing temperature, the alternating aging process ends); in the above 2nd, 3rd,... After the alternating aging process is all over, continue the final cooling process: Finally, continue to use a specific cooling method to cool the austenitic stainless steel from the above maximum or minimum temperature of the temperature-changing and alternating-aging to room temperature (the second part starts quickly with high-temperature alternating-temperature alternating. The aging heat treatment process is all over).

[0118] It can be seen from the above technical solutions that the present invention can fundamentally solve the problems of poor quality stability, low qualified product rate, low hardness (or low mechanical properties) and poor consistency, heating Long time, low efficiency, poor heating reliability of heat treatment equipment, low service life of high-temperature components, and high cost "one long, one high, three poor and five low" are unique to the theoretical and practical problems of heat treatment technology.

[0119] The above is only a preferred embodiment of the present invention. Although the present invention takes the heat treatment method of austenitic stainless steel (the heating equipment used is the existing traditional box-type resistance heating furnace) as the research object, it is also applicable to Other types of heat treatment methods such as stainless steel and superalloy (heating equipment can also be selected: other types of resistance heating furnaces, medium and low frequency heating furnaces, salt bath heating furnaces, gas fuel fuel heating furnaces, fluid particle heating furnaces, vacuum heating furnaces, etc.) ; Similarly, it is also applicable to the heat treatment methods involved in the field of hot processing engineering such as austenitic stainless steel smelting, steel rolling, forging and heat treatment involved in steel mills and manufacturing plants; at the same time, it should also be pointed out that: for For those of ordinary skill in the art, without departing from the technical principles of the present invention, several arrangements, combinations, deformations and improvements can also be made (especially according to the grades of austenitic stainless steel, service performance and heating equipment, etc. Different appropriate adjustment or change of the solid solution and aging heating temperature and heating time and cooling medium, etc.) should also be regarded as the protection scope of the present invention.