Online heat treatment temperature control method for cold-drawn seamless steel pipe

Abstract

Disclosed in the present invention is an online heat treatment temperature control method for a cold-drawn seamless steel pipe. The method comprises: arbitrarily selecting one of cold-drawn steel pipes, and evenly attaching a plurality of thermocouple temperature sensors to the outer surface of the selected cold-drawn steel pipe, and then feeding same as a whole into a heat treatment furnace, wherein a plurality of heat treatment units are evenly distributed in the heat treatment furnace, and each heat treatment unit can automatically adjust the temperature; setting a fitting function to acquire the average temperature of a cold-drawn steel pipe segment below each heat treatment unit, and comparing same with a preset rated temperature; and compensating each cold-drawn steel pipe segment by means of classified compensation and cyclic compensation, such that the final temperature of the cold-drawn steel pipe segment infinitely approaches the rated temperature, thereby ensuring the temperature equalization of the entire cold-drawn steel pipe. The method enables uniform heat treatment of an entire cold-drawn steel pipe, thereby improving the quality of heat treatment.

Description

A method for online heat treatment temperature control of cold-drawn seamless steel pipes Technical Field

[0001] This invention relates to the field of cold-drawn steel pipe production technology, specifically to a method for online heat treatment temperature control of cold-drawn seamless steel pipes. Background Technology

[0002] Currently, cold-drawn steel pipes are widely used in many fields, such as the automotive industry, machinery industry, oil and gas industry, energy industry, electronics and communications industry, and medical devices. As a high-precision, high-quality steel pipe product, the manufacturing process of cold-drawn steel pipes is a complex process involving multiple steps, typically including raw material preparation, pretreatment, cold drawing, heat treatment, straightening and flaw detection, quality inspection and marking, and warehousing. The main function of heat treatment is to eliminate residual stress inside the steel pipe and improve its mechanical properties, playing a crucial role in whether the cold-drawn steel pipe can be used. However, current heat treatment methods for cold-drawn steel pipes have the following shortcomings:

[0003] 1. Currently produced cold-drawn steel pipes are quite long, but temperature sensors are only placed at the inlet and outlet of the heat treatment furnace. With only a limited number of temperature sensors measuring the temperature, it is impossible to accurately know the temperature of the cold-drawn steel pipe, let alone the temperature distribution of the entire steel pipe.

[0004] 2. Existing heat treatment furnaces regulate the temperature of cold-drawn steel pipes by simply raising or lowering the temperature based on the temperature measured by a limited number of temperature sensors, without considering the actual temperature of a certain area of ​​the cold-drawn steel pipe. This results in the production of cold-drawn steel pipes with different performance characteristics in different areas of the same steel pipe. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides an online heat treatment temperature control method for cold-drawn seamless steel pipes, which can achieve uniform temperature throughout the entire cold-drawn steel pipe.

[0006] The technical solution adopted in this invention is: a method for online heat treatment temperature control of cold-drawn seamless steel pipes, comprising the following steps:

[0007] Step S1: Before heat treatment, select any one cold-drawn steel pipe and attach n thermocouple temperature sensors to its outer surface. Place one thermocouple temperature sensor at each end of the selected cold-drawn steel pipe and the rest evenly. With the direction from the inlet to the outlet of the heat treatment furnace as the direction, denote the thermocouple temperature sensors attached to the cold-drawn steel pipe as temperature sensor k, where k = 1, 2, 3...n.

[0008] Place the cold-drawn steel pipe with the thermocouple temperature sensor attached in the middle of all the cold-drawn steel pipes, and then put them into the heat treatment furnace side by side; the heat treatment furnace area corresponding to the location of the cold-drawn steel pipe is composed of m heat treatment units, each heat treatment unit can be individually adjusted in temperature, and the length of each heat treatment unit is l. After the heat treatment furnace has been working for t0 time, proceed to step S2.

[0009] Step S2: Taking the location of thermocouple temperature sensor 1 as the origin of the coordinate system, and the distance from the inlet to the outlet of the heat treatment furnace as the positive direction, record the distance from the remaining locations of the cold-drawn steel pipe to the origin of the coordinate system as x, and record the temperature measured by thermocouple temperature sensor k as t. k Where k = 1, 2, 3…n, and temperature t is denoted as t. k Let y be the value; based on the arrangement of the thermocouple temperature sensors on the selected cold-drawn steel pipe, let the temperature sensor k-position-temperature coordinate be A. k A k The expression is Where k = 1, 2, 3...n;

[0010] Step S3: Let the fitting function T(x) be used to reflect the temperature distribution of the complete cold-drawn steel pipe. The expression for T(x) is T(x) = Cx. (n-1) +Dx (n-2) +Ex (n-3) +…+Gx+H, where C, D, E…H are coefficients, and the position-temperature coordinates A… k Substituting into the fitting function T(x), we obtain the values ​​of all coefficients; based on the temperature distribution T(x) of the complete cold-drawn steel pipe, we obtain the specific temperature of the cold-drawn steel pipe of the corresponding length in each heat treatment unit, and denot the average temperature of the cold-drawn steel pipe of the corresponding length in the i-th heat treatment unit as T. i Where: i = 1, 2, 3...m;

[0011] Step S4: Based on the average temperature T of the cold-drawn steel pipe of the corresponding length in each heat treatment unit. i Temperature compensation is performed, and the rated heat treatment temperature is denoted as T. 额 Calculate the average temperature T of the cold-drawn steel pipe corresponding to the length of the heat treatment unit. i With the required rated temperature T 额 Temperature difference ΔT i ΔT i The calculation formula is ΔT i =T 额 -T i Where i = 1, 2, 3...m; calculate the temperature difference ΔT. i and rated temperature T 额 The relative difference ratio τ, the formula for calculating τ is: Based on the relative difference ratio τ, the temperature of the cold-drawn steel pipe is compensated by adjusting the temperature of the heat treatment unit, so that the cold-drawn steel pipe is heated evenly in all parts.

[0012] As a further improvement of the present invention, the temperature compensation step in step S4 is as follows:

[0013] Step S41, set As the first boundary point, when And ΔT i When the value is greater than 0, the temperature compensation function ΔT for the heat treatment unit is given. 偿 = -k1t + b1, where k1 is the value of ΔT i The relevant constant coefficients, and k1 > 0, b1 is related to ΔT i The relevant constant coefficients are given, and b1 > 0. t is a time variable, and the cutoff time of t is δ1. The judgment condition is t ≠ T, where T is the period of temperature compensation of the heat treatment unit. If the condition t ≠ T is met, then continue to execute this step. If the condition t = T is met, then return to step S2.

[0014] Step S42, when And ΔT i When <0, give the temperature compensation function ΔT for the heat treatment unit. 偿 =k1t-b1, where k1 is the value of ΔT i The relevant constant coefficients, and k1 > 0, b1 is related to ΔT i The relevant constant coefficients are given, and b1 > 0. t is a time variable, and the deadline for t is δ1. The condition for judgment is t ≠ T. If the condition t ≠ T is satisfied,

[0015] Then continue with this step. If the condition t = T is met, return to step S2.

[0016] Step S43, set For the second boundary point, when And ΔT i When the value is greater than 0, the temperature compensation function ΔT for the heat treatment unit is given. 偿 = -k2t + b2, where k2 is the sum of k and ΔT. i The relevant constant coefficients, and k2 > 0, and k1 > k2, b2 is related to ΔT i The relevant constant coefficients are given, and b2 > 0. The deadline for t is δ2. The judgment condition is t ≠ T. If the condition t ≠ T is met, continue to execute this step. If the condition t = T is met, return to step S2.

[0017] Step S44, when And ΔT i When <0, provide the corresponding temperature compensation function ΔT for the heat treatment unit. 偿=k2t-b2, where k2 is the sum of k2 and ΔT. i The relevant constant coefficients are k2 > 0 and k1 > k2, b2 is related to ΔT i The relevant constant coefficients, and b2 > 0, the deadline of t is δ2; the judgment condition t ≠ T, if the condition t ≠ T is met, then continue to execute this step, if the condition t = T is met, then return to step S2;

[0018] Step S45, when And ΔT i When <0, the corresponding temperature compensation function for the heat treatment unit is given. Where k3 is related to ΔT i The relevant constant coefficients, and k3 > 0, and k1 > k3, b3 is related to ΔT i The relevant constant coefficients, and b3 > 0, the deadline of t is δ3; the judgment condition t ≠ T, if the condition t ≠ T is met, then continue to execute this step, if the condition t = T is met, then return to step S2;

[0019] Step 46, when And ΔT i When the value is greater than 0, the temperature compensation function for the heat treatment unit is given. Where k3 is related to ΔT i The relevant constant coefficients, and k3 > 0, and k1 > k3, b3 is related to ΔT i The relevant constant coefficients are given, and b3 > 0. The cutoff time for t is δ3. The judgment condition is t ≠ T. If the condition t ≠ T is met, then continue to execute this step. If the condition t = T is met, then return to step S2.

[0020] As a further improvement of the present invention, the number of thermocouple temperature sensors is 5 to 7.

[0021] As a further improvement of the present invention, the working time t0 before measurement is 120s or 180s.

[0022] As a further improvement of the present invention, the temperature compensation period T of the heat treatment unit is 120s or 180s.

[0023] As a further improvement to the present invention, the first boundary point The range of values ​​is

[0024] As a further improvement to the present invention, the second boundary point The range of values ​​is

[0025] As a further improvement of the present invention, the value range of the cutoff time δ1 is 0.4T < δ1 < 0.6T.

[0026] As a further improvement of the present invention, the value range of the cutoff time δ2 is 0.8T < δ2 < 1T.

[0027] As a further improvement of the present invention, the value range of the cutoff time δ3 is 0.45T < δ3 < 0.55T.

[0028] The beneficial effects of this invention are:

[0029] (1) The present invention has multiple heat treatment units evenly distributed above the heat treatment furnace. Each heat treatment unit can automatically adjust the temperature. Multiple thermocouple temperature sensors are evenly set on the calibrated cold-drawn steel pipe. The heat treatment unit collects the temperature of the cold-drawn steel pipe section below it and then uses classification compensation and cyclic compensation to make the temperature of the entire cold-drawn steel pipe evenly distributed, release the residual stress inside, and thus improve the heat treatment quality of the cold-drawn steel pipe.

[0030] (2) The present invention can perform precise temperature compensation for cold-drawn steel pipes and achieve different compensation schemes under different conditions, thereby making the temperature of each section of the cold-drawn steel pipe approach the rated temperature and ensuring the temperature uniformity of the entire cold-drawn steel pipe. Attached Figure Description

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 is a schematic diagram of the heat treatment furnace of the present invention;

[0033] Figure 2 is a flowchart of the temperature compensation process for cold-drawn steel pipes according to the present invention.

[0034] In Figure 1, 1-cold-drawn steel pipe, 2-thermocouple temperature sensor, 3-heat treatment unit, 4-support device, and 5-heat treatment furnace. Detailed Implementation

[0035] Please refer to Figures 1 and 2. The present invention provides a method for online heat treatment temperature control of cold-drawn seamless steel pipes, comprising the following steps:

[0036] Step S1: Before heat treatment, arbitrarily select one cold-drawn steel pipe 1 and attach n thermocouple temperature sensors 2 to its outer surface. One thermocouple temperature sensor is placed at each end of the selected cold-drawn steel pipe, and the rest are evenly distributed. Taking the direction from the inlet to the outlet of the heat treatment furnace 5 as the direction, denote the thermocouple temperature sensors attached to the cold-drawn steel pipe as temperature sensor k, where k = 1, 2, 3...n. Specifically, the number of thermocouple temperature sensors is 5 to 7.

[0037] The cold-drawn steel pipe with the thermocouple temperature sensor 2 attached is placed in the middle of all the cold-drawn steel pipes, and then placed side by side into the heat treatment furnace 5 and placed on the support device 4; the heat treatment furnace area corresponding to the position of the cold-drawn steel pipe is composed of m heat treatment units 3. Each heat treatment unit 3 is used for heating. Both the heat treatment unit 3 and the thermocouple temperature sensor 2 are connected to the controller. The controller collects the real-time temperature of the thermocouple and adjusts the temperature of the heat treatment unit.

[0038] The length of each heat treatment unit is denoted as l. Step S2 is executed after the heat treatment furnace has been operating for time t0, where t0 is 120s or 180s. This step uses a single cold-drawn steel pipe as a marker, and multiple thermocouple temperature sensors are installed on it. The temperature sensed by this marker can be generalized to the temperature measurement of all other cold-drawn steel pipes entering the heat treatment furnace. This invention first heats the cold-drawn steel pipes entering the heat treatment furnace for a period of time, i.e., time period t0, to bring their overall temperature to around the rated temperature before compensation.

[0039] Step S2: Taking the location of temperature sensor 1 as the origin of the coordinate system, and the distance from the inlet to the outlet of the heat treatment furnace as the positive direction, record the distance from the remaining locations of the cold-drawn steel pipe to the origin as x, and record the temperature measured by temperature sensor k as t. k Where k = 1, 2, 3...n, and temperature t is denoted as t. k Let y be the value; based on the arrangement of the thermocouple temperature sensors on the selected cold-drawn steel pipe, let the temperature sensor k-position-temperature coordinate be A. k A k The expression is Where k = 1, 2, 3...n;

[0040] Step S3: Let the fitting function T(x) be used to reflect the temperature distribution of the complete cold-drawn steel pipe. The expression for T(x) is T(x) = Cx. (n-1) +Dx (n-2) +Ex (n-3) +...+Gx+H, where C, D, E...H are coefficients, and the position-temperature coordinates A... k Substituting into the fitting function T(x), we obtain the values ​​of all coefficients; based on the temperature distribution T(x) of the complete cold-drawn steel pipe, we obtain the specific temperature of the cold-drawn steel pipe of the corresponding length in each heat treatment unit, and denot the average temperature of the cold-drawn steel pipe of the corresponding length in the i-th heat treatment unit as T. i , where i = 1, 2, 3... m.

[0041] Specifically, by using the property of area integrals of functions, the average temperature T of the cold-drawn steel pipe of the corresponding length in the i-th heat treatment unit can be obtained. i T i The calculation formula is Where: i = 1, 2, 3... m.

[0042] Step S4: Based on the average temperature T of the cold-drawn steel pipe of the corresponding length in each heat treatment unit. i Temperature compensation is performed, and the rated heat treatment temperature is denoted as T. 额 Calculate the average temperature T of the cold-drawn steel pipe corresponding to the length of the heat treatment unit. i With the required rated temperature T 额 Temperature difference ΔT i ΔT i The calculation formula is ΔT i =T 额 -T i Where i = 1, 2, 3...m; calculate the temperature difference ΔT. i and rated temperature T 额 The relative difference ratio τ, the formula for calculating τ is: Based on the relative difference ratio τ, the temperature of the cold-drawn steel pipe is compensated by adjusting the temperature of the heat treatment unit, so that the cold-drawn steel pipe is heated evenly in all parts.

[0043] Specifically, the steps for temperature compensation are as follows:

[0044] Step S41, set As the first boundary point, when And ΔT i When the value is greater than 0, the temperature compensation function ΔT for the heat treatment unit is given. 偿 = -k1t + b1, where k1 is the value of ΔT i The relevant constant coefficients, and k1 > 0, b1 is related to ΔT i The relevant constant coefficients are defined, and b1 > 0. t is a time variable, and the cutoff time of t is δ1. The judgment condition is t ≠ T, where T is the period of temperature compensation in the heat treatment unit. If the condition t ≠ T is met, continue to this step; if the condition t = T is met, return to step S2. First boundary point. The range of values ​​is The cutoff time δ1 ranges from 0.4T < δ1 < 0.6T, and the temperature compensation cycle T of the heat treatment unit is 120S or 180S. The cycle T remains the same in all the following steps. In this compensation function, when the function's time t reaches the cutoff time δ1, compensation for this type of situation stops. t continues to run, and when it reaches T, i.e., t = T, it returns to step S2 to perform cyclic compensation. The cutoff principle of the following compensation functions is the same. Regarding setting the cycle T, since the temperature compensation of the heat treatment furnace is a repetitive cyclic process, every cycle T, the thermocouple temperature sensor measures the temperature once, and then performs temperature compensation again based on this temperature; after one cycle ends, it measures again and performs temperature compensation again. This not only checks whether the previous temperature compensation was effective, but also allows the actual temperature of the entire cold-drawn steel pipe to approach the rated temperature more closely through cyclic compensation.

[0045] Step S42, when And ΔT i When <0, give the temperature compensation function ΔT for the heat treatment unit. 偿 =k1t-b1, where k1 is the value of ΔT i The relevant constant coefficients, and k1 > 0, b1 is related to ΔT i The relevant constant coefficients are given, and b1 > 0. The cutoff time for t is δ1. The judgment condition is t ≠ T, where T is the period of temperature compensation performed by the heat treatment unit. If the condition t = T is met, then continue to execute this step; if the condition t ≠ T is not met, then return to step S2. During compensation, ΔT i A value >0 indicates that the overall temperature of this section of cold-drawn steel pipe is higher than the set temperature, while ΔT i If the value is less than 0, it means that the overall temperature of this section of cold-drawn steel pipe is less than the rated temperature.

[0046] Step S43, set For the second boundary point, when And ΔT i When the value is greater than 0, the temperature compensation function ΔT for the heat treatment unit is given. 偿 = -k2t + b2, where k2 is the sum of k and ΔT. i The relevant constant coefficients, and k2 > 0, and k1 > k2, b2 is related to ΔT i The relevant constant coefficients are given, and b2 > 0. The cutoff time for t is δ2. The judgment condition is t ≠ T, where T is the period of temperature compensation of the heat treatment unit. If the condition t ≠ T is met, continue to execute this step; if the condition t = T is met, return to step S2. Second boundary point. The range of values ​​is

[0047] Step S44, when And ΔT iWhen <0, provide the corresponding temperature compensation function ΔT for the heat treatment unit. 偿 =k2t-b2, where k2 is the sum of k2 and ΔT. i The relevant constant coefficients are k2 > 0 and k1 > k2, b2 is related to ΔT i The relevant constant coefficients, and b2 > 0, the cutoff time of t is δ2; if the condition t ≠ T, then continue to execute this step; if the condition t = T is met, then return to step S2; the range of the cutoff time δ2 is 0.8T < δ2 < T.

[0048] Step S45, when And ΔT i When <0, the corresponding temperature compensation function for the heat treatment unit is given.

[0049] Where k3 is related to ΔT i The relevant constant coefficients, and k3 > 0, and k1 > k3, b3 is related to ΔT i The relevant constant coefficients are given, and b3 > 0, the cutoff time of t is δ3; the judgment condition is t ≠ T. If the condition t ≠ T is met, then continue to execute this step; if the condition t ≠ T is not met, then return to step S2; the range of the cutoff time δ3 is 0.45T < δ3 < 0.55T.

[0050] Step 46, when And ΔT i When the value is greater than 0, the temperature compensation function for the heat treatment unit is given. Where k3 is related to ΔT i The relevant constant coefficients, and k3 > 0, and k1 > k3, b3 is related to ΔT i The relevant constant coefficients are given, and b3 > 0. The cutoff time for t is δ3. The condition t ≠ T is checked. If the condition t ≠ T is met, the current step is continued. If the condition t ≠ T is not met, the process returns to step S2.

[0051] This temperature compensation uses the ratio of the absolute value of the temperature difference to the rated temperature for classification compensation, and handles three cases separately:

[0052] In the first case, the actual temperature deviates very little from the required temperature (including positive and negative deviations), corresponding to steps 41 and 42 of this method.

[0053] In the second case, the actual temperature deviates little from the required temperature, corresponding to steps 43 and 44 of this method.

[0054] In the third case, the actual temperature deviates significantly from the required temperature, corresponding to steps 45 and 46 of this method.

[0055] This invention first divides the cold-drawn steel pipe into sections, with each section equipped with a thermocouple temperature sensor and a heat treatment unit. Then, temperature compensation is performed on each section individually. By classifying the temperature differences, refined compensation is implemented, and multiple cycles of compensation are conducted until the temperature of each section approaches its rated temperature, at which point the process stops. Compared to existing technologies, this invention effectively releases residual stress in the cold-drawn steel pipe and improves the overall heat treatment quality.

[0056] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes that can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. A method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes, characterized in that, Includes the following steps: Step S1: Before heat treatment, select any one cold-drawn steel pipe and attach n thermocouple temperature sensors to its outer surface. Place one thermocouple temperature sensor at each end of the selected cold-drawn steel pipe and the rest evenly. With the direction from the inlet to the outlet of the heat treatment furnace as the direction, denote the thermocouple temperature sensors attached to the cold-drawn steel pipe as temperature sensor k, where k = 1, 2, 3...n. Place the cold-drawn steel pipe with the thermocouple temperature sensor attached in the middle of all the cold-drawn steel pipes, and then put them into the heat treatment furnace side by side; the heat treatment furnace area corresponding to the location of the cold-drawn steel pipe is composed of m heat treatment units, each heat treatment unit can be individually adjusted in temperature, and the length of each heat treatment unit is l. After the heat treatment furnace has been working for t0 time, proceed to step S2. Step S2: Taking the location of thermocouple temperature sensor 1 as the origin of the coordinate system, and the distance from the inlet to the outlet of the heat treatment furnace as the positive direction, record the distance from the remaining locations of the cold-drawn steel pipe to the origin as x, and record the temperature measured by thermocouple temperature sensor k as t. k Where k = 1, 2, 3...n, and temperature t is denoted as t. k Let y be the value; based on the arrangement of the thermocouple temperature sensors on the selected cold-drawn steel pipe, let the temperature sensor k-position-temperature coordinate be A. k A k The expression is Where k = 1, 2, 3...n; Step S3: Let the fitting function T(x) be used to reflect the temperature distribution of the complete cold-drawn steel pipe. The expression for T(x) is T(x) = Cx. (n-1) +Dx (n-2) +Ex (n-3) +…+Gx+H, where C, D, E…H are coefficients, and the position-temperature coordinates A… k Substitute the values ​​into the fitting function T(x) to obtain the values ​​of all coefficients; Based on the temperature distribution T(x) of the complete cold-drawn steel pipe, the specific temperature of the cold-drawn steel pipe of the corresponding length in each heat treatment unit is obtained. Let T be the average temperature of the cold-drawn steel pipe of the corresponding length in the i-th heat treatment unit. i Where: i = 1, 2, 3...m; Step S4: Based on the average temperature T of the cold-drawn steel pipe of the corresponding length in each heat treatment unit. i Temperature compensation is performed, and the rated heat treatment temperature is denoted as T. 额 Calculate the average temperature T of the cold-drawn steel pipe corresponding to the length of the heat treatment unit. i With the required rated temperature T 额 Temperature difference ΔT i ΔT i The calculation formula is ΔT i =T 额 -T i Where i = 1, 2, 3...m; calculate the temperature difference ΔT. i and rated temperature T 额 The relative difference ratio τ, the formula for calculating τ is: Based on the relative difference ratio τ, the temperature of the cold-drawn steel pipe is compensated by adjusting the temperature of the heat treatment unit to ensure that all parts of the cold-drawn steel pipe are heated evenly.

2. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 1, characterized in that, In step S4, the specific steps for temperature compensation are as follows: Step S41, set As the first boundary point, when And ΔT i When the value is greater than 0, the temperature compensation function ΔT for the heat treatment unit is given. 偿 = -k1t + b1, where k1 is the value of ΔT i The relevant constant coefficients, and k1 > 0, b1 is related to ΔT i The relevant constant coefficients are given, and b1 > 0. t is a time variable, and the cutoff time of t is δ1. The judgment condition is t ≠ T, where T is the period of temperature compensation of the heat treatment unit. If the condition t ≠ T is met, then continue to execute this step. If the condition t = T is met, then return to step S2. Step S42, when And ΔT i When <0, give the temperature compensation function ΔT for the heat treatment unit. 偿 =k1t-b1, where k1 is the value of ΔT i The relevant constant coefficients, and k1 > 0, b1 is related to ΔT i The relevant constant coefficients are given, and b1 > 0. t is a time variable, and the deadline of t is δ1. The judgment condition is t ≠ T. If the condition t ≠ T is met, continue to execute this step. If the condition t = T is met, return to step S2. Step S43, set For the second boundary point, when And ΔT i When the value is greater than 0, the temperature compensation function ΔT for the heat treatment unit is given. 偿 = -k2t + b2, where k2 is the sum of k and ΔT. i The relevant constant coefficients, and k2 > 0, and k1 > k2, b2 is related to ΔT i The relevant constant coefficients are given, and b2 > 0. The cutoff time for t is δ2. The judgment condition is t ≠ T. If the condition t ≠ T is met, continue to execute this step. If the condition t = T is met, return to step S2. Step S44, when And ΔT i When <0, provide the corresponding temperature compensation function ΔT for the heat treatment unit. 偿 =k2t-b2, where k2 is the sum of k2 and ΔT. i The relevant constant coefficients are k2 > 0 and k1 > k2, b2 is related to ΔT i The relevant constant coefficients, and b2 > 0, the deadline of t is δ2; the judgment condition t ≠ T, if the condition t ≠ T is met, then continue to execute this step, if the condition t = T is met, then return to step S2; Step S45, when And ΔT i When <0, the corresponding temperature compensation function for the heat treatment unit is given. Where k3 is related to ΔT i The relevant constant coefficients, and k3 > 0, and k1 > k3, b3 is related to ΔT i The relevant constant coefficients, and b3 > 0, the deadline of t is δ3; the judgment condition t ≠ T, if the condition t ≠ T is met, then continue to execute this step, if the condition t = T is met, then return to step S2; Step 46, when And ΔT i When the value is greater than 0, the temperature compensation function for the heat treatment unit is given. Where k3 is related to ΔT i The relevant constant coefficients, and k3 > 0, and k1 > k3, b3 is related to ΔT i The relevant constant coefficients are given, and b3 > 0. The cutoff time for t is δ3. The judgment condition is t ≠ T. If the condition t ≠ T is met, then continue to execute this step. If the condition t = T is met, then return to step S2.

3. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 1, characterized in that, The number of thermocouple temperature sensors should be 5 to 7.

4. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 1, characterized in that, The working time t0 before measurement is set to 120s or 180s.

5. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 2, characterized in that, The temperature compensation cycle T of the heat treatment unit is 120s or 180s.

6. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 2, characterized in that, First boundary point The range of values ​​is 7. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 2, characterized in that, Second boundary point The range of values ​​is 8. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 2, characterized in that, The range of the deadline δ1 is 0.4T < δ1 < 0.6T.

9. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 2, characterized in that, The range of the deadline δ2 is 0.8T < δ2 < 1T.

10. The method for controlling the online heat treatment temperature of cold-drawn seamless steel pipes according to claim 2, characterized in that, The range of the deadline δ3 is 0.45T < δ3 < 0.55T.

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