Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a blank heat treatment method and a blank heat treatment device, which can heat a tube blank by using the Joule effect of pulse current during treatment, so that the temperature of each point on the blank tends to be consistent, the plastic deformation capacity of the blank is improved, the plastic flow of a material is promoted to be continuous and uniform, and the material deformation resistance of the blank is reduced, so that the transverse crack defect is avoided during the subsequent blank perforation forming, the rejection rate is reduced, the forming power consumption is reduced, the production quality is improved, and the production benefit can be greatly improved.
In order to solve the technical problems, the invention provides the following technical scheme:
specifically, the invention provides a heat treatment method of a blank, which comprises the following steps:
s1, setting initial parameters: determining a heating environment i (i is 1,2,3) and a heating precision requirement KiThe temperature T required by the blank perforation heat treatment, the maximum limit temperature difference delta T of each point of the blank after the pulse current heating is finished and the temperature measuring thermocouple temperature measuring time interval T, wherein when i is 1, the blank is heated in a heating furnace, when i is 2, the blank is heated by a flame spraying mode, and when i is 3, the blank is heated in an environment where the pulse current is applied; the precision requirement after the heating in the heating furnace is K1The temperature precision requirement after the flaming heating is K2The precision requirement after the heating by applying the pulse current is K3;
S2, heating the blank by a heating furnace, which comprises the following steps:
s21, heating the blank in a heating furnace, detecting the temperature of each point on the blank in the heating furnace in real time by using a temperature measuring device, transmitting the real-time temperature data to an upper computer, determining the maximum value of the temperature by the upper computer by comparing the temperature of each point on the outer surface of the blank in the heating furnace, and calculating the following formula:
T
1max=max{T
1’,T
1”,T
1”’,...,T
1 (n)then calculating the actual accuracy of the heating process in the furnace
S22 actual accuracy K in heating process in heating furnace1' and heating in a heating furnaceFinished precision requirement K1And (3) comparison: if K1’<K1Then, the steps S21-S22 are repeated until K1’≥K1(ii) a If K1’≥K1Then the step S3 is entered for next heating;
s3, carrying out flame spraying heating on the blank, which specifically comprises the following substeps:
s31, moving out of the heating furnace, carrying out flame spraying on the blank, stopping flame spraying after t time, inserting a temperature thermocouple into the blank to detect the temperature of the core part of the blank, transmitting real-time temperature data of each point on the inner surface of the blank to an upper computer in real time by the temperature thermocouple, comparing the temperature of each point on the inner surface of the blank in flame spraying heating by the upper computer, and determining the maximum value of the temperature, wherein the calculation formula is as follows:
T2max=max{T2’,T2”,T2”’,...,T2 (n)calculating the actual accuracy in the flaming heating process
S32 actual precision K in heating process in flaming mode2' with accuracy requirement K after completion of heating in flaming mode2And (3) comparison: if K2’<K2Repeating the steps S31-S32 until K2’≥K2(ii) a If K2’≥K2Then, the process goes to step S4 to perform the next heating process;
s4, heating the blank by pulse current, which comprises the following steps:
s41, stopping flaming heating, heating the blank in the environment of pulse current application, increasing the temperature of the blank by the joule heat of the pulse current, inserting a temperature thermocouple into the blank to detect the temperature of each point of the core of the blank in the environment of pulse current application in real time, detecting the temperature of each point of the outer surface of the blank in the environment of pulse current application in real time by an infrared thermometer, and detecting the inner surface of the blank and the detected temperature of each point of the outer surface of the blank in the environment of pulse current application in real timeThe temperature data of the outer surface is transmitted to an upper computer in real time; after the upper computer receives the temperature data, the temperature of each point on the inner surface and the outer surface of the blank in the environment of applying the pulse current is compared to obtain the maximum temperature value and the minimum temperature value, and the calculation formula of the maximum temperature value is T3max=max{T3’,T3”,T3”’,...,T3 (n)The calculation formula of the minimum value of the temperature is T3min=min{T3’,T3”,T3”’,...,T3 (n)};
S42, calculating the maximum temperature difference delta T' between the inner surface and the outer surface of the blank under the environment of the pulse current application according to the maximum temperature value and the minimum temperature value and the actual precision in the heating process in the environment of the pulse current application
S43 actual accuracy K in heating process in environment of pulse current application3' with accuracy requirement K after completion of heating in an environment where a pulse current is applied3Comparing, and simultaneously comparing the maximum temperature difference delta T' of the blank with the maximum limit temperature difference delta T of the blank:
if K3’<K3If yes, repeating the steps S41-S43; if K3’≥K3If delta T' is greater than delta T, stopping applying the pulse current, and ensuring that the temperature of each point on the blank tends to be consistent through a heat conduction mode;
if K3’≥K3Delta T' is less than or equal to delta T and T3minIf the temperature is less than T, the heating is continuously carried out in the environment of pulse current, and the temperature of the lowest point of the blank is raised by using the joule heat of the pulse current;
if K3’≥K3Δ T' is less than or equal to Δ T, and T3minAnd if the temperature is more than or equal to T, stopping pulse heating, and taking out the blank to perform a subsequent punching process.
In step S41, the infrared thermometer reciprocates by means of the slide rail, thereby measuring the temperature of each point on the outer surface of the billet.
Preferably, the invention further provides a blank heat treatment device, which comprises a workbench, an upper computer, a pulse power supply, a flaming heating assembly, a thermocouple temperature measuring assembly, a control console and a lead screw transmission assembly arranged on the workbench, wherein the lead screw transmission assembly comprises a first slide rail, a first fixed slide block, a first movable slide block and a first lead screw which are fixedly arranged on the workbench, the first end of the first slide rail is fixedly connected with the first fixed slide block, the second end of the first slide rail is provided with the first movable slide block which can move, the first lead screw penetrates through the space between the first fixed slide block and the first movable slide block, the first lead screw and the first movable slide block are connected through a connecting piece and then further connected with a first motor so as to realize the reciprocating motion of the first movable slide block on the first slide rail, the top ends of the first fixed slide block and the first movable slide block are respectively embedded with a pulse current anode and a pulse current cathode, the side surface of the workbench is symmetrically provided with infrared temperature measurement components;
the flaming heating assembly comprises a second slide rail, a second fixed slide block, a second movable slide block and a second lead screw, the second fixed slide block is arranged on the second slide rail, the second lead screw is arranged between the second fixed slide block and the second movable slide block, the second lead screw is connected with a second motor, a first hydraulic cylinder is fixed on the second movable slide block, the first hydraulic cylinder is connected with a first hydraulic pump assembly, the other end of the first hydraulic cylinder is fixedly connected with an air inlet pipe support, and a spark plug ignition device is fixed on the air inlet pipe support;
the infrared temperature measurement assembly comprises a first infrared temperature measurement assembly and a second temperature measurement assembly, the first infrared temperature measurement assembly comprises a third slide rail, a third fixed slide block, a third movable slide block and a third lead screw, the third fixed slide block is fixed on one side of the third slide rail, the third lead screw penetrates through the third movable slide block and is connected with a third motor, a first supporting rod is fixed on the third movable slide block, a first infrared thermometer is connected onto the first supporting rod, and the second infrared temperature measurement assembly and the first infrared temperature measurement assembly are symmetrically distributed on the side face of the workbench;
the thermocouple temperature measuring component comprises a fourth sliding rail, a fourth fixed sliding block, a fourth movable sliding block and a fourth lead screw, the fourth fixed sliding block is arranged on the side face of the first motor, the fourth fixed sliding block is fixed on the fourth sliding rail, the fourth lead screw is arranged on the fourth sliding rail, the fourth movable sliding block is arranged on the fourth lead screw and is connected with the fourth motor, a second hydraulic cylinder is fixed on the fourth movable sliding block and is connected with a second hydraulic pump component fixed on a second oil tank, the other end of the second hydraulic cylinder is fixedly connected with a thermocouple support, and a temperature measuring thermocouple is arranged on the thermocouple support.
Preferably, the hard pipe that admits air sets up on the intake pipe support, the hard pipe front end of admitting air is seted up and is 90 bocca that distribute along circumference, the hard pipe rear end of admitting air is admitted air the hose and is admitted air the hose through oxygen and natural gas and link to each other with oxygen gas pitcher and natural gas pitcher respectively.
Preferably, the top ends of the first fixed sliding block and the first movable sliding block are provided with inclined planes which are symmetrically distributed, so that blanks with different diameters can be supported.
Preferably, the front end of the air inlet hard pipe of the flame spraying assembly is divided into a plurality of sections, the air inlet hard pipe is provided with a thread pair, the air inlet hard pipes of the plurality of sections are fixedly connected through the thread pair, so that flame spraying treatment on blanks with different lengths is realized, the hydraulic cylinder below the air inlet pipe support can be driven by the hydraulic pump to extend and contract, and therefore the height of the air inlet pipe support is adjusted, so that flame spraying treatment on blanks with different diameters is realized.
Preferably, a taper air inlet for preventing backfire is arranged in the natural gas inlet hard pipe, and the spark plug ignition device comprises a spark plug and an ignition coil.
Preferably, when the blank is heated by the heating furnace, the position of the first movable slide block is adjusted by the console according to the length and the diameter of the blank, so that the sum of the distance between the first movable slide block and the first fixed slide block is close to the total length of the stainless steel tube blank, and the length of the air inlet hard tube and the height of the air inlet tube bracket are adjusted at the same time.
Preferably, the other end of the first hydraulic cylinder is connected with the air inlet pipe bracket and the first support rod is connected with the first infrared thermometer by means of connecting pieces.
Preferably, the other end of the first hydraulic cylinder is connected with the air inlet pipe support through a bolt, and the first support rod is connected with the first infrared thermometer through a cylindrical pin.
Compared with the prior art, the invention has the following beneficial effects:
(1) the blank after primary heating in the heating furnace is subjected to heat treatment in a pulse current auxiliary flame spraying mode, and during working, the blank is firstly placed in the heating furnace to be heated to a certain temperature, at the moment, the temperature difference between the inner surface and the outer surface of the blank is large, so that the temperature of the core part of the blank is rapidly increased in a flame spraying mode inside the blank, the temperature difference between the inner part and the outer part of the blank can be reduced, then pulse current is applied for heating, the temperature difference of the blank in different directions is reduced by utilizing the joule heat effect of the pulse current, the temperature of each point on the surface of the blank tends to be uniform, and the transverse crack defect generated during the punching process can be reduced.
(2) The invention adopts pulse current for heating, the pulse current is used as transient energy, which can provide motive power for diffusion and migration of atoms in the blank, when the pulse current passes through the blank, the atoms on the crack surfaces at two sides can be promoted to form bonding combination again, the original long crack is converted into short microcrack, holes are further formed, then, under the action of the pulse current, dislocation and atoms in the blank can move and fill the holes, and finally, under the combined action of pressing and filling mechanisms, the size and the number of the holes are gradually reduced, so that the microcrack on the blank is finally healed, and the quality of the blank is improved.
(3) The pulse current can improve the heating efficiency, reduce the heat preservation time and the oxidation in the heating process, improve the plastic deformation capacity of the tube blank, promote the continuous and uniform plastic flow of the material, and reduce the deformation resistance of the material of the tube blank, thereby avoiding the occurrence of transverse crack defects, reducing the rejection rate of seamless steel tubes, reducing the forming power consumption, improving the production quality and greatly improving the production benefit during the subsequent perforation forming of the tube blank.
Detailed Description
Exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
Specifically, the present invention provides a heat treatment method of a billet, as shown in fig. 6, which includes the steps of:
s1, setting initial parameters: determining a heating environment i (i is 1,2,3) and a heating precision requirement KiThe temperature T required by the blank perforation heat treatment, the maximum limit temperature difference delta T of each point of the blank after the pulse current heating is finished and the temperature measuring thermocouple temperature measuring time interval T, wherein when i is 1, the blank is heated in a heating furnace, when i is 2, the blank is heated by a flame spraying mode, and when i is 3, the blank is heated in an environment where the pulse current is applied; the precision requirement after the heating in the heating furnace is K1The temperature precision requirement after the flaming heating is K2The precision requirement after the heating by applying the pulse current is K3。
S2, heating the blank by a heating furnace, which comprises the following substeps:
s21, heating the blank in a heating furnace, detecting the temperature of each point on the blank in the heating furnace in real time by using a temperature measuring device, transmitting the real-time temperature data to an upper computer, determining the maximum value of the temperature by the upper computer by comparing the temperature of each point on the outer surface of the blank in the heating furnace, and calculating the following formula:
T
1max=max{T
1’,T
1”,T
1”’,...,T
1 (n)then calculating the actual accuracy of the heating process in the furnace
S22 actual accuracy K in heating process in heating furnace1' with accuracy requirement K after completion of heating in heating furnace1And (3) comparison: if K is1’<K1Then repeatSteps S21-S22 until K1’≥K1(ii) a If K1’≥K1Then the process proceeds to step S3 for the next heating.
S3, carrying out flame spraying heating on the blank, which specifically comprises the following substeps:
s31, moving out of the heating furnace, carrying out flame spraying on the blank, stopping flame spraying after t time, inserting a temperature thermocouple into the blank to detect the temperature of the core part of the blank, transmitting real-time temperature data of each point on the inner surface of the blank to an upper computer in real time by the temperature thermocouple, comparing the temperature of each point on the inner surface of the blank in flame spraying heating by the upper computer, and determining the maximum value of the temperature, wherein the calculation formula is as follows: t is2max=max{T2’,T2”,T2”’,...,T2 (n)Calculating the actual accuracy in the flaming heating process
S32 actual precision K in heating process in flaming mode2' with accuracy requirement K after completion of heating in flaming mode2And (3) comparison: if K2’<K2Repeating the steps S31-S32 until K2’≥K2(ii) a If K2’≥K2Then, the process proceeds to step S4 to perform the next heating process.
S4, heating the blank by pulse current, which comprises the following steps:
s41, stopping flaming heating, heating the blank in an environment with pulse current, increasing the temperature of the blank by using the joule heat of the pulse current, inserting a temperature thermocouple into the blank to detect the temperature of each point of the core part of the blank in the environment with the pulse current in real time, detecting the temperature of each point of the outer surface of the blank in the environment with the pulse current in real time by using an infrared thermometer, and transmitting the detected temperature data of the inner surface and the outer surface of the blank to an upper computer in real time; after receiving the temperature data, the upper computer compares the blanks in the environment of applying the pulse currentThe temperature of each point on the inner and outer surfaces of the material is obtained to obtain the maximum temperature value and the minimum temperature value, and the calculation formula of the maximum temperature value is T3max=max{T3’,T3”,T3”’,...,T3 (n)The calculation formula of the minimum value of the temperature is T3min=min{T3’,T3”,T3”’,...,T3 (n)};
S42, calculating the maximum temperature difference delta T' between the inner surface and the outer surface of the blank under the environment of the pulse current application according to the maximum temperature value and the minimum temperature value and the actual precision in the heating process in the environment of the pulse current application
S43 actual accuracy K in heating process in environment of pulse current application3' with accuracy requirement K after completion of heating in an environment where a pulse current is applied3Comparing, and simultaneously comparing the maximum temperature difference delta T' of the blank with the maximum limit temperature difference delta T of the blank:
if K is3’<K3If yes, repeating the steps S41-S43; if K3’≥K3If delta T' is greater than delta T, stopping applying the pulse current, and enabling the temperature of each point on the blank to be consistent in a heat conduction mode;
if K3’≥K3Delta T' is less than or equal to delta T and T3minIf the temperature is less than T, the heating is continuously carried out in the environment of pulse current, and the temperature of the lowest point of the blank is raised by using the joule heat of the pulse current;
if K3’≥K3Δ T' is less than or equal to Δ T, and T3minAnd if the temperature is more than or equal to T, stopping pulse heating, and taking out the blank to perform a subsequent punching process.
As shown in figure 1, the invention provides a heat treatment device for a stainless steel pipe blank, which comprises a blank 14 (a stainless steel pipe blank), a workbench 34, an upper computer 29, a pulse power supply 32, a pulse current electrode, a flaming heating assembly 11, a thermocouple temperature measuring assembly, a control console 31, infrared temperature measuring assemblies and a lead screw transmission assembly, wherein the two infrared temperature measuring assemblies are transversely and symmetrically fixedly arranged at two sides of the workbench 34, the lead screw transmission assembly is fixed between the two infrared temperature measuring assemblies, the flaming heating assembly 34 is arranged at one side of the stainless steel pipe blank 14, the pulse power supply 32 and the control console 31 are arranged at the other side of the stainless steel pipe blank 14, and the upper computer 29 is arranged in front of the control console 31. The host computer 29 is a computer or a central control machine or other controller in the embodiment.
The screw drive assembly comprises a first slide rail 16 transversely fixedly mounted on the workbench 34, a first movable slide block 18, a first fixed slide block 13 and a first screw 15, a first fixed slide block 13 is fixedly welded at the first end of the first slide rail 16, a first movable slide block 18 capable of moving is arranged at the second end of the first slide rail 16, a first screw 15 is arranged between the first fixed slide block 13 and the first movable slide block 18 in a penetrating mode, and the first screw 15 and the first movable slide block 18 are connected through bolts and a first motor 20 to achieve movement of the first movable slide block 18 on the first slide rail 16.
The flaming heating assembly comprises a second slide rail 5 arranged on the side face of a first fixed slide block 13, a second movable slide block 42, a second fixed slide block 41 and a second lead screw, a second lead screw 7 is arranged between the second fixed slide block 41 and the second movable slide block 42 which can move and welded on the second slide rail 5 in a penetrating manner, the second lead screw 7 is connected with a second motor 6, a first hydraulic cylinder 43 is fixed on the second movable slide block 42, the first hydraulic cylinder 43 is connected with a first hydraulic pump assembly 1, the first hydraulic pump assembly 1 comprises a first oil tank 101, a first hydraulic pump 102 and a motor 103, one end of the first hydraulic cylinder 43 is connected with a first hydraulic pump 102 fixed on the first oil tank 101, and the first hydraulic pump 102 is provided with a hydraulic motor 103. The other end of the first hydraulic cylinder 43 is fixedly connected with the air inlet pipe support 114 through a bolt or other connecting pieces, the air inlet hard pipe 111 comprises an oxygen air inlet hard pipe 1112 and a natural gas air inlet hard pipe 1111, the air inlet hard pipe 111 is erected on the air inlet pipe support 114, the air inlet pipe support 114 is fixed with a spark plug ignition device 112, the first end of the air inlet hard pipe 111 is provided with a flame jet 113 which is distributed at 90 degrees along the circumferential direction, and the second ends of the oxygen air inlet hard pipe 1112 and the natural gas air inlet hard pipe 1111 are respectively connected with the oxygen gas tank 9 and the natural gas tank 3 through an oxygen air inlet hose 10 and a natural gas inlet hose 2. The natural gas tank 3 is mounted by means of a natural gas tank mount 4. The oxygen tank 9 is fixed by means of an oxygen tank mount 8.
The infrared temperature measurement assembly comprises a first infrared temperature measurement assembly and a second infrared temperature measurement assembly, the first infrared temperature measurement assembly comprises a third sliding rail 38 fixed on the workbench, a third fixed sliding block 40, a third movable sliding block 35 and a third lead screw 39, the third fixed sliding block 40 is welded on one side of the third sliding rail 38, the third lead screw 39 penetrates through the third movable sliding block 35 and then is connected with a third motor 33, a first supporting rod 36 is fixed on the third movable sliding block 35, a first infrared thermometer 37 fixed by a taper pin or other connecting pieces is arranged on the first supporting rod 36, and the second infrared temperature measurement assembly 17 and the first infrared temperature measurement assembly are symmetrically distributed on the side face of the workbench 34.
The thermocouple temperature measurement component comprises a fourth slide rail 21 arranged on the side face of the first motor, a fourth lead screw 28, a fourth movable slide block 26 and a fourth fixed slide block 30, the fourth fixed slide block 30 is welded on the fourth slide rail 21, the fourth lead screw 28 is arranged between the fourth fixed slide block 30 and the fourth movable slide block 26 in a penetrating mode, the fourth lead screw 28 is connected with a fourth motor 25, a second hydraulic cylinder 24 is fixed on the fourth movable slide block 26, the first end of the second hydraulic cylinder 24 is connected with a second hydraulic pump component 27, the second end of the second hydraulic cylinder 24 is fixedly connected with a thermocouple support 23, and a temperature thermocouple 22 is arranged on the thermocouple support 23. The specific components of the second hydraulic pump assembly 27 are the same as those of the first hydraulic pump assembly 1, and will not be described herein.
As shown in fig. 2, the top ends of the first fixed sliding block 13 and the first movable sliding block 18 are provided with inclined planes which are symmetrically distributed to support stainless steel pipe blanks 14 with different diameters, meanwhile, the inclined planes at the top ends of the first fixed sliding block 13 and the first movable sliding block 18 are respectively embedded with a pulse current anode 19 and a pulse current cathode 12, and the material of the inclined planes at the top ends is selected to have excellent insulation and high temperature resistance, in a specific embodiment, the material of the pulse current electrodes embedded on the inclined planes at the top ends of the first fixed sliding block 13 and the first movable sliding block 18 is selected to be copper with very small resistance, and in the specific embodiment, the material of the inclined planes at the top ends is selected to be Hp5 mica plates with excellent insulation and high temperature resistance.
As shown in fig. 3, the front end of the air inlet hard pipe 111 of the flame-throwing heating assembly 11 is divided into a plurality of sections, and the sections are fixedly connected through thread pairs thereon to realize flame-throwing treatment of stainless steel pipe blanks 14 with different lengths, and the first hydraulic cylinder 43 below the air inlet pipe bracket 114 can be extended and contracted under the driving of the first hydraulic pump 1, so that the height of the air inlet pipe bracket 114 can be conveniently adjusted to realize flame-throwing treatment of stainless steel pipe blanks with different diameters.
As shown in fig. 4, the spark plug ignition device 112 includes an ignition coil 1121 and a spark plug 1122.
As shown in fig. 5, a conical air inlet is arranged in the natural gas inlet hard pipe 1111, and the conical air inlet can play a role in preventing backfire.
The working process and working principle of the present invention are further described below with reference to the following embodiments:
the following examples the parameters of the blanks to be heat treated and of the pulse current used are specified in the following table:
1. the billet parameters are as follows:
2. the pulse current parameters are given in the following table:
3. the temperature thermocouple temperature measurement time interval t parameter is shown in the following table:
specific example 1:
in this embodiment, the following table data is selected for the initial parameters:
the method specifically comprises the following steps:
step 1, setting initial parameters: determining a heating environment i (i is 1,2 and 3), wherein when i is 1, the stainless steel pipe blank 14 is heated in a heating furnace, when i is 2, the stainless steel pipe blank 14 is heated by means of flaming, and when i is 3, the stainless steel pipe blank 14 is heated in an environment where pulse current is applied; heating accuracy requirement KiWherein the precision requirement after the heating in the heating furnace is K1The temperature precision requirement after the flaming heating is K2The precision requirement after the heating by applying the pulse current is K3(ii) a The temperature T required by the piercing heat treatment of the stainless steel tube blank 14; after the pulse current heating is finished, the maximum limiting temperature difference delta T of each point of the stainless steel pipe blank 14 is achieved; measuring the temperature interval t by the temperature thermocouple;
step 2, adjusting the position of the first movable slide block 18 through a control console 31 according to the length and the diameter of the stainless steel tube blank 14, enabling the sum of the distances between the first movable slide block 18 and the first fixed slide block 13 to be close to the total length of the stainless steel tube blank 14, and adjusting the length of the air inlet hard tube 111 and the height of the air inlet tube bracket 114;
step 3, the stainless steel pipe blank 14 is placed in a heating furnace to be heated, i is equal to 1, the temperature of each point on the stainless steel pipe blank 14 in the heating furnace is detected in real time through a temperature measuring device in the heating furnace, temperature data are transmitted to an
upper computer 29 in real time, and the
upper computer 29 determines the maximum value T of the temperature of each point on the stainless steel pipe blank 14 in the heating furnace through comparison
1max=max{T
1’,T
1”,T
1”’,...,T
1 (n)After the minimum value of the temperature of each point in the heating furnace is determined, the
upper computer 29 starts to calculate the heating in the heating furnace
Step 4, actual precision K in the heating process in the heating furnace1' with accuracy requirement K after completion of heating in heating furnace1And (3) comparison:
(1) if K1’<0.7,Repeating the step 3-4;
(2) if K1' is more than or equal to 0.7, and the next heating process is carried out;
step 5, the stainless steel pipe blank 14 is placed in an i-2 mode, namely, heating is carried out in a flaming mode, after T time, flaming stops, the second motor 6 works to bring the
flaming assembly 11 out of the stainless steel pipe blank 14, the
fourth motor 25 works to insert the
temperature thermocouple 22 into the stainless steel pipe blank 14 to detect the temperature of the core of the stainless steel pipe blank 14, the
temperature thermocouple 22 transmits temperature data of all points on the inner surface of the stainless steel pipe blank 14 to the
upper computer 29 in real time, and the
upper computer 29 determines the maximum value T of the temperature of all points on the inner surface of the stainless steel pipe blank 14 in the flaming mode through comparison
2max=max{T
2’,T
2”,T
2”’,...,T
2 (n)After the maximum value of the temperature of each point in the flaming mode is determined, the
upper computer 29 starts to calculate the actual precision in the heating process in the flaming mode
Step 6, actual precision K in the heating process in the flame spraying mode2' with accuracy requirement K after completion of heating in flaming mode2And (3) comparison:
(1) if K2' < 0.92, repeating steps 5-6;
(2) if K2' > 0.92 or more, and carrying out the next heating process;
and 7, stopping flaming heating, enabling the second motor 6 to work to bring the flaming assembly 11 out of the stainless steel pipe blank 14, enabling the fourth motor 25 to work to insert the temperature thermocouple 22 into the stainless steel pipe blank 14 to detect the temperature of the core part of the stainless steel pipe blank 14 in real time, enabling the two infrared thermometers to synchronously reciprocate on the sliding rails to realize real-time detection of the temperature of each point on the surface of the stainless steel pipe blank 14 in the environment of applying pulse current, transmitting the temperature data of the inner surface and the outer surface to the upper computer 29 in real time, then placing the stainless steel pipe blank 14 in the environment of applying the pulse current with the condition that i is 3 to heat the stainless steel pipe blank, and utilizing the joule heat of the pulse current to improve the temperature of the blankAfter receiving the temperature data, the upper computer 29 determines the maximum value T of the temperature at each point on the inner and outer surfaces of the stainless steel pipe blank 14 in the environment where the pulse current is applied by comparison3max=max{T3’,T3”,T3”’,...,T3 (n)And a minimum value T3min=min{T3’,T3”,T3”’,...,T3 (n)After the maximum value of the temperature of each point in the environment of applying the pulse current is determined, the upper computer 29 starts to calculate the maximum temperature difference delta T' of the inner surface and the outer surface of the stainless steel pipe blank 14 in the environment of applying the pulse current and the actual precision in the heating process in the environment of applying the pulse current
Step 8, actual precision K in the heating process in the environment of pulse current application3' with accuracy requirement K after completion of heating in an environment where a pulse current is applied3Comparing, and simultaneously comparing the maximum temperature difference delta T' of the stainless steel pipe blank 14 with the maximum limit temperature difference delta T of the stainless steel pipe blank 14:
(1) if K3' < 1, repeating the step 7-8;
(2) if K3'is more than or equal to 1, and Delta T' is more than 30 ℃, the application of pulse current is stopped, and the temperature of each point on the stainless steel tube blank 14 tends to be consistent through a heat conduction mode of the stainless steel tube blank 14;
(3) if K3'is not less than 1, Delta T' is not more than 30 ℃, and T3minIf the temperature is less than 1210 ℃, the stainless steel tube blank is continuously heated in the environment of pulse current, and the temperature of the lowest point of the stainless steel tube blank 14 is raised by using the joule heat of the pulse current;
(4) if K is3'is not less than 1, Delta T' is not more than 30 ℃, and T3minStopping pulse heating when the temperature is more than or equal to 1210 ℃, and taking out the stainless steel tube blank 14 to perform a subsequent perforation process;
specific example 2:
a TP316 stainless steel pipe blank with the initial temperature of 26 ℃ and the diameter of 329mm multiplied by 3000mm is taken to be heated to the temperature 1210 ℃ required by the perforation heat treatment, and the method comprises the following steps:
step 1, adjusting the position of the first movable slide block 18 through the control console 31 according to the length and the diameter of the stainless steel tube blank 14, enabling the sum of the distance between the first movable slide block 18 and the first fixed slide block 13 to be close to 3000mm, and adjusting the length of the air inlet hard tube 111 and the height of the air inlet tube support 114 to enable the height of the axes of the air inlet hard tube flame-throwing port, the stainless steel tube blank and the like.
Step 2, placing the stainless steel pipe blank 14 in a heating furnace for heating, detecting the temperature of each point on the stainless steel pipe blank 14 in real time through a temperature measuring device in the heating furnace, transmitting the real-time temperature data to an upper computer 29 in real time, and determining the maximum value T of the temperature of each point on the stainless steel pipe blank 14 in the heating furnace by the upper computer 29 through comparing the temperature of each point1maxWhen the temperature is 860 ℃, the upper computer 29 starts to calculate the actual precision K in the heating process in the heating furnace according to a calculation formula1’≈0.71。
Step 3, by comparing K1' > 0.7, and therefore the next heating step is carried out.
Step 4, taking out the stainless steel tube blank 14, placing the stainless steel tube blank on the first fixed slide block 13 and the first movable slide block 18, and then heating the stainless steel tube blank by adopting a flame spraying mode, wherein delta T is caused at the moment21110-2maxWhen the actual accuracy K in the heating process in the flaming mode starts to be calculated by the upper computer 29 at 1030 DEG C2’≈0.85。
Step 5, by comparing K2' < 0.92, so the heating is carried out by flame spraying, since the Delta T is in this case21110 + 1030 + 80 ℃, so that the flaming stops after 2s, and then the second motor 6 works to bring the flaming assembly 11 outThe fourth motor 25 works at the same time inside the stainless steel pipe blank 14 to insert the temperature thermocouple 22 into the stainless steel pipe blank 14 to detect the temperature of the core part of the stainless steel pipe blank 14, the temperature thermocouple 22 transmits the temperature data of each point on the inner surface of the stainless steel pipe blank 14 to the upper computer 29 in real time, and the upper computer 29 determines the maximum value T of the temperature of each point on the inner surface of the stainless steel pipe blank 14 in a flaming mode through comparison2maxWhen the actual accuracy K in the heating process in the flaming mode begins to be calculated by the upper computer 29 at 1130 DEG C2’≈0.93。
Step 6, by comparing K2' more than 0.92, stopping the flaming heating, enabling the second motor 6 to work to bring the flaming assembly 11 out of the stainless steel tube blank 14, enabling the fourth motor to work to insert the temperature thermocouple 22 into the stainless steel tube blank 14 to detect the temperature of the core of the stainless steel tube blank 14 in real time, enabling the two infrared thermometers to synchronously reciprocate on the slide rail to detect the temperature of each point on the outer surface of the stainless steel tube blank 14 in the environment of applying the pulse current in real time, transmitting the temperature data of the inner surface and the outer surface to the upper computer 29 in real time, then placing the stainless steel tube blank 14 in the environment of applying the pulse current to heat, utilizing the joule heat of the pulse current to increase the temperature of the blank, and after the upper computer 29 receives the temperature data, comparing and determining the maximum value T of the temperature of each point on the inner surface and the outer surface of the stainless steel tube blank 14 in the environment of applying the pulse current3max1230 ℃ and minimum T3min1160 ℃, the maximum temperature difference delta T' of the inner surface and the outer surface of the stainless steel pipe blank 14 is 70 ℃, and the actual heating precision K3’≈1.02。
Step 7, by comparing K3'is more than or equal to 1, and Delta T' is more than 30 ℃, the application of the pulse current is stopped, so that the temperature of each point on the stainless steel tube blank 14 tends to be consistent through the stainless steel tube blank 14 in a heat conduction mode, the temperature thermocouple and the infrared thermometer continuously carry out real-time detection on the temperature of each point on the inner surface and the outer surface of the stainless steel tube blank 14, and after a period of heat conduction, the maximum value T of the temperature of each point on the inner surface and the outer surface of the stainless steel tube blank 14 is3max1220 ℃ and minimum value T3min1190 deg.C, maximum temperature difference delta T' between inner surface and outer surface of stainless steel tube blank 14 equals 30 deg.C, and actual heating precision K3’≈1.01。
Step 8, comparing the above values to find K3'is not less than 1, Delta T' is not more than 30 ℃, and T3minThe temperature is less than 1210 ℃, so the heating is continuously carried out in the environment of pulse current, the temperature of the lowest point of the stainless steel tube blank 14 is improved by using the joule heat of the pulse current, the temperature measuring thermocouple and the infrared thermometer continuously carry out real-time detection on the temperature of each point on the inner surface and the outer surface of the stainless steel tube blank 14, and after the pulse current is heated for a period of time, the maximum value T of the temperature of each point on the inner surface and the outer surface of the stainless steel tube blank 143max1230 ℃ and minimum T3min1210 deg.C, 20 deg.C of maximum temp. difference delta T' between internal and external surfaces of stainless steel tube blank 14, and actual heating precision K3’≈1.02。
Step 9, by comparing K3'is not less than 1, Delta T' is not more than 30 ℃, and T3minAnd stopping pulse heating at 1210 ℃, and taking out the stainless steel tube blank 14 for a subsequent punching process.
According to researches, the TP316 stainless steel pipe blank with the initial temperature of 26 ℃, the diameter of 300mm multiplied by 3000mm needs to be heated for 8 hours when the initial temperature is up to the process temperature of 1210 ℃, and the heat is preserved for 3 hours, which is 11 hours in total. The final inspection showed a rejection rate of 10.3% due to cracking, while the heating of the stainless steel tube blank using the apparatus and process proposed by the present invention was carried out for a total of 7.55 hours, and the final inspection showed a rejection rate of 5.2% due to cracking.
Finally, it should be noted that: the above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.