Method for determining quenching start residence time, quenching method and surface induction heating device

Abstract

The invention relates to the technical field of induction heating, in particular to a method for determining quenching starting retention time, a quenching method and a surface induction heating device. The method for determining the quenching start residence time comprises the following steps: assembling a surface induction heating device; and the surface induction heating quenching-starting retention time t of the metal workpiece is determined. The quenching method comprises the following steps: assembling the surface induction heating device; the surface induction heating quenching-starting retention time t of the metal workpiece is determined; and quenching heating operation and quenching spraying cooling operation on the surface of the metal workpiece are completed. The device comprises a surface induction heating device for determining the quenching start residence time and a surface induction heating device for completing the quenching method. The method can solve the problems that in the prior art, the quenching temperature is too high or too low due to the fact that the quenching starting retention time is difficult to accurately determine, and then quenching of the metal workpiece is unqualified or even scrapped.

Description

Technical Field

[0001] The invention relates to the technical field of induction heating, and in particular to a method for determining a quenching residence time, a quenching method and a surface induction heating device. Background Art

[0002] Induction heating is an efficient and fast heating method, which is often used for surface hardening of metal workpieces. Specifically, first, the surface of the metal workpiece is quickly heated by induction heating; then, the surface of the metal workpiece is quickly cooled to achieve quenching. Induction heating can improve the hardness and wear resistance of the surface of the metal workpiece while maintaining the toughness of the core. Induction heating is suitable for various metal workpieces that require surface hardening, such as shaft parts, gears, bearings, camshafts, valves, etc.

[0003] However, during induction heating, it is difficult to control the heating temperature of the starting heating position on the surface of the metal workpiece to reach the quenching temperature. Therefore, in the actual quenching operation on the surface of the metal workpiece, the industry controls the heating temperature of the starting heating position to reach the quenching temperature by setting the quenching dwell time, so as to ensure that the required hardened layer depth and hardness are obtained in the subsequent cooling process. At present, the method for determining the quenching dwell time in the industry is generally determined by observing the color change of the metal workpiece based on production experience. This makes it difficult to accurately determine the quenching dwell time; correspondingly, this will directly cause the heating temperature of the starting heating position of the metal workpiece to be higher than the quenching temperature or lower than the quenching temperature. If the quenching dwell time is too long, it will directly cause the heating temperature of the starting heating position of the metal workpiece to be higher than the quenching temperature, so that the starting heating position of the metal workpiece undergoes a fierce martensitic transformation in the subsequent cooling process, resulting in excessive surface tensile stress, thereby generating surface quenching cracks, resulting in unqualified or scrapped workpieces. If the quenching dwell time is too short, it will directly cause the heating temperature of the starting heating position of the metal workpiece to be lower than the quenching temperature, so that the hardened layer depth or hardness obtained at the starting heating position of the metal workpiece in the subsequent cooling process is insufficient.

[0004] In summary, it is necessary to provide a method for determining the quenching residence time, a quenching method and a surface induction heating device to solve the problem in the prior art that the quenching residence time is difficult to accurately determine, resulting in the quenching temperature being too high or too low, which in turn leads to unqualified quenching of the metal workpiece or even scrapping. Summary of the invention

[0005] The object of the present invention is to provide a method for determining the dwell time of quenching, a quenching method and a surface induction heating device. The specific technical scheme is as follows: In a first aspect, the present invention provides a method for determining the quenching residence time, using a surface induction heating device to determine the surface induction heating residence time of a metal workpiece. t ; The surface induction heating device comprises a machine tool, an electromagnetic heating inductor and a main control machine; a turntable and a mechanical arm are arranged on the machine tool; a metal workpiece is arranged on the turntable; the electromagnetic heating inductor is arranged on the mechanical arm; the electromagnetic heating inductor is arranged above the metal workpiece and connected to an external power supply; a working gap is arranged between the electromagnetic heating inductor and the metal workpiece; the main control machine is arranged on the machine tool and connected to the electromagnetic heating inductor, the turntable and the mechanical arm; Determine the surface induction heating quenching residence time of the metal workpiece t The following steps are involved: The main control machine is used to start the electromagnetic heating sensor at a first heating rate v 1. Heat to the Curie point temperature of the metal workpiece T θ ; Using the host control machine to control the electromagnetic heating sensor at the second heating rate v 2Next T θ Raise the temperature to the target quenching temperature of the metal workpiece T ; The following formula is used to determine the surface induction heating quenching residence time of the metal workpiece: t : ; in, v The value range of 1 is 150-350℃ / s; v The value range of 2 is 50-120℃ / s.

[0006] Optionally, the working gap is 2-5 mm.

[0007] Optionally, the voltage of the electromagnetic heating inductor during operation is 50-70 kV.

[0008] In a second aspect, the present invention provides a quenching method, comprising: Step B1, assembling a tracker and a sprayer on the surface induction heating device in the method for determining the quenching residence time; A tracker is arranged on the metal workpiece; the sprayer is arranged on the robot arm; the sprayer is arranged above the metal workpiece; a control valve is arranged on the sprayer, and the sprayer is connected to an external water source through a pipeline; the main control machine is connected to the tracker and the control valve on the sprayer; Step B2: Determine the surface induction heating quenching residence time of the metal workpiece by using the method for determining the quenching residence time. t ; Step B3, completing the quenching heating operation and the quenching spray cooling operation on the surface of the metal workpiece; The main control machine is used to control the electromagnetic heating inductor to stay for a certain time during the quenching process. t Internal heating to target quenching temperature T ; At the same time, the main control machine is used to start the turntable to drive the metal workpiece to rotate for one circle to complete the quenching and heating operation on the surface of the metal workpiece; wherein, the tracker is used to obtain the working gap data between the electromagnetic heating sensor and the metal workpiece in real time, and send it to the main control machine; the main control machine controls the mechanical arm to link the electromagnetic heating sensor in real time according to the change of the working gap data, and controls the working gap between the electromagnetic heating sensor and the metal workpiece to be maintained at 2-5mm; The main control machine is used to close the electromagnetic heating sensor and open the control valve on the sprayer to realize the spraying operation; at the same time, the main control machine is used to start the turntable to drive the metal workpiece to rotate one circle to complete the quenching spray cooling operation on the surface of the metal workpiece.

[0009] Optionally, the metal workpiece includes any one of a shaft workpiece, a gear, a bearing, a camshaft, a valve and a wear-resistant ring.

[0010] In a third aspect, the present invention provides a surface induction heating device, comprising a machine tool, an electromagnetic heating inductor and a main control machine; a turntable and a robotic arm are arranged on the machine tool; a metal workpiece is arranged on the turntable; the electromagnetic heating inductor is arranged on the robotic arm; the electromagnetic heating inductor is arranged above the metal workpiece and connected to an external power supply; a working gap is arranged between the electromagnetic heating inductor and the metal workpiece; the main control machine is arranged on the machine tool and connected to the electromagnetic heating inductor, the turntable and the robotic arm.

[0011] Optionally, the working gap is 2-5 mm.

[0012] Optionally, the surface induction heating device further includes a tracker and a sprinkler; A tracker is arranged on the metal workpiece; the sprinkler is arranged on the robot arm; the sprinkler is arranged above the metal workpiece; a control valve is arranged on the sprinkler, and the sprinkler is connected to an external water source through a pipeline; the main control machine is connected to the tracker and the control valve on the sprinkler.

[0013] Optionally, the control valve includes a solenoid valve.

[0014] Optionally, the main control machine includes a PLC controller.

[0015] The application of the technical solution of the present invention has at least the following beneficial effects: (1) The present invention provides a method for determining the quenching dwell time, which can be based on the Curie point temperature of the metal workpiece. T θ and target quenching temperature T , using a specific first heating rate v 1st and 2nd heating rates v 2. Combined quenching residence time t The calculation expression of The quenching dwell time is accurately obtained to ensure that the heating temperature of the initial heating position of the metal workpiece reaches the quenching temperature, so that the initial heating position of the metal workpiece can obtain the required hardened layer depth and hardness in the subsequent cooling process, which solves the problem in the prior art that the quenching dwell time is difficult to accurately determine, resulting in too high or too low quenching temperature, which in turn leads to unqualified quenching of the metal workpiece or even scrapping.

[0016] (2) The quenching method provided by the present invention can accurately obtain the quenching dwell time, ensure that the heating temperature of the starting heating position of the metal workpiece reaches the quenching temperature, so that the starting heating position of the metal workpiece obtains the required hardened layer depth and hardness in the subsequent cooling process; the tracker is used to obtain the working gap data between the electromagnetic heating sensor and the metal workpiece in real time, and sends it to the main control computer; the main control computer controls the mechanical arm to link with the electromagnetic heating sensor in real time according to the change of the working gap data, and controls the working gap between the electromagnetic heating sensor and the metal workpiece to be maintained at 2-5mm. The setting of the working gap can prevent the metal workpiece from being quenched during quenching. The problem of lowering or increasing the quenching temperature due to deformation and the increase or decrease of the working gap between the metal workpiece and the electromagnetic heating inductor arises, that is, ensuring that the heating temperature of all heating positions of the metal workpiece is the quenching temperature, so that all heating positions of the metal workpiece can obtain the required hardened layer depth and hardness in the subsequent cooling process; if the working gap is too small, the heating speed of the metal workpiece after being heated by the electromagnetic heating inductor is too fast, the metal workpiece is easily deformed by heat, and the electromagnetic heating inductor may collide with the deformed part of the metal workpiece, resulting in the risk of shutdown and thermal damage to the metal workpiece; if the working gap is too large, the heating speed of the metal workpiece after being heated by the electromagnetic heating inductor is too slow, resulting in waste of electric energy.

[0017] (3) The surface induction heating device for determining the quenching residence time provided by the present invention can accurately obtain the quenching residence time.

[0018] (4) The surface induction heating device provided by the present invention for completing the quenching method can ensure that the heating temperature of all heating positions of the metal workpiece is the quenching temperature, so that all heating positions of the metal workpiece can obtain the required hardened layer depth and hardness during the subsequent cooling process.

[0019] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a schematic structural diagram of a surface induction heating device in Example 1 of the present invention; Figure 2 is a relationship diagram for determining the quenching dwell time and the quenching temperature in Example 1 of the present invention; Figure 3 is a relationship diagram for determining the quenching dwell time and the quenching temperature in Example 2 of the present invention; Among them, 1. electromagnetic heating sensor, 2. tracker, 3. sprinkler, P, metal workpiece. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention. Embodiment 1:

[0022] Method for determining the dwell time of quenching, using a surface induction heating device to determine the dwell time of surface induction heating of a metal workpiece t ; See also Figure 1 The surface induction heating device comprises a machine tool (not shown in the figure), an electromagnetic heating inductor 1 and a main control machine (specifically a PLC controller, not shown in the figure); a turntable (not shown in the figure) and a mechanical arm (not shown in the figure) are arranged on the machine tool; a metal workpiece P is arranged on the turntable; the electromagnetic heating inductor 1 is arranged on the mechanical arm; the electromagnetic heating inductor 1 is arranged above the metal workpiece P and connected to an external power supply; a working gap is arranged between the electromagnetic heating inductor 1 and the metal workpiece P; the main control machine is arranged on the machine tool and connected to the electromagnetic heating inductor 1, the turntable and the mechanical arm; Determine the surface induction heating quenching residence time of the metal workpiece P t The following steps are involved: See also Figure 2, the main control machine is used to start the electromagnetic heating sensor 1 at a first heating rate v 1 to the Curie point temperature of the metal workpiece P T θ ; Using the host control machine to control the electromagnetic heating sensor 1 at the second heating rate v 2Next T θ The temperature is raised to the target quenching temperature of the metal workpiece P. T The metal workpiece P is a wear-resistant ring, which is made of 42CrMo, and the Curie point temperature T θ The target quenching temperature is 770℃ T It is 850℃.

[0023] The following formula is used to determine the surface induction heating quenching residence time of the metal workpiece P: t : ; in, v The value range of 1 is 220℃ / s; v The value of 2 is 54.29℃ / s; the dwell time of quenching t It is 4.97s.

[0024] The working gap is 3 mm.

[0025] The voltage of the electromagnetic heating inductor 1 during operation is 60 kV.

[0026] A quenching method, comprising: Step B1, assembling the tracker 2 and the sprayer 3 on the surface induction heating device; See also Figure 1 , a tracker 2 is arranged on the metal workpiece P; the sprayer 3 is arranged on the robot arm; the sprayer 3 is arranged above the metal workpiece P; a control valve is arranged on the sprayer 3, and the sprayer 3 is connected to an external water source through a pipeline; the main control machine is connected to the tracker 2 and the control valve on the sprayer 3; Step B2: Determine the surface induction heating quenching residence time of the metal workpiece P by using the method for determining the quenching residence time. t ; Step B3, completing the quenching heating operation and the quenching spray cooling operation on the surface of the metal workpiece P; The main control machine is used to control the electromagnetic heating inductor 1 to stay for a certain time during the quenching period. t Internal heating to target quenching temperature T; At the same time, the main control machine is used to start the turntable to drive the metal workpiece P to rotate one circle to complete the quenching and heating operation on the surface of the metal workpiece P; wherein, the tracker 2 is used to obtain the working gap data between the electromagnetic heating sensor 1 and the metal workpiece P in real time, and send it to the main control machine; the main control machine controls the robot arm to link the electromagnetic heating sensor 1 in real time according to the change of the working gap data, and controls the working gap between the electromagnetic heating sensor 1 and the metal workpiece P to be maintained at 3mm; The main control machine is used to close the electromagnetic heating inductor 1 and open the control valve on the sprayer 3 to realize the spraying operation; at the same time, the main control machine is used to start the turntable to drive the metal workpiece P to rotate one circle to complete the quenching spray cooling operation on the surface of the metal workpiece P.

[0027] See also Figure 1 The surface induction heating device includes a machine tool, an electromagnetic heating inductor 1 and a main control machine; a turntable and a robotic arm are arranged on the machine tool; a metal workpiece P is arranged on the turntable; the electromagnetic heating inductor 1 is arranged on the robotic arm; the electromagnetic heating inductor 1 is arranged above the metal workpiece P and connected to an external power supply; a working gap (specifically 3 mm) is arranged between the electromagnetic heating inductor 1 and the metal workpiece P; the main control machine is arranged on the machine tool and connected to the electromagnetic heating inductor 1, the turntable and the robotic arm.

[0028] See also Figure 1 The surface induction heating device also includes a tracker 2 and a sprayer 3; the tracker 2 is arranged on the metal workpiece P; the sprayer 3 is arranged on the robot arm; the sprayer 3 is arranged above the metal workpiece P; a control valve is arranged on the sprayer 3, and the sprayer 3 is connected to an external water source through a pipeline; the main control machine is connected to the tracker 2 and the control valve (specifically a solenoid valve) on the sprayer 3. Embodiment 2:

[0029] See also Figure 3 The metal workpiece P is a wear-resistant ring made of GCr15, and its Curie point temperature is T θ The target quenching temperature is 770℃ T 880℃; v The value range of 1 is 183.3℃ / s; v The value of 2 is 50℃ / s; the dwell time of quenching t The working gap is 4 mm. The voltage of the electromagnetic heating inductor 1 during operation is 70 kV.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for determining the quenching residence time, characterized in that: Determining the surface induction heating quenching residence time of metal workpieces using surface induction heating equipment t ; The surface induction heating device comprises a machine tool, an electromagnetic heating inductor and a main control machine; a turntable and a mechanical arm are arranged on the machine tool; a metal workpiece is arranged on the turntable; the electromagnetic heating inductor is arranged on the mechanical arm; the electromagnetic heating inductor is arranged above the metal workpiece and connected to an external power supply; a working gap is arranged between the electromagnetic heating inductor and the metal workpiece; the main control machine is arranged on the machine tool and connected to the electromagnetic heating inductor, the turntable and the mechanical arm; Determine the surface induction heating quenching residence time of the metal workpiece t The following steps are involved: The main control machine is used to start the electromagnetic heating sensor at a first heating rate v 1. Heat to the Curie point temperature of the metal workpiece T θ ; Using the host control machine to control the electromagnetic heating sensor at the second heating rate v 2Next T θ Raise the temperature to the target quenching temperature of the metal workpiece T ; The following formula is used to determine the surface induction heating quenching residence time of the metal workpiece: t : ； in, v The value range of 1 is 150-350℃ / s; v The value range of 2 is 50-120℃ / s.

2. The method for determining the quenching residence time according to claim 1, characterized in that: The working gap is 2-5 mm.

3. The method for determining the quenching residence time according to claim 1, characterized in that: The voltage of the electromagnetic heating inductor during operation is 50-70 kV.

4. A quenching method, characterized in that: include: Step B1, assembling a tracker and a sprayer on the surface induction heating device in the method for determining the quenching residence time according to any one of claims 1 to 3; A tracker is arranged on the metal workpiece; the sprayer is arranged on the robot arm; the sprayer is arranged above the metal workpiece; a control valve is arranged on the sprayer, and the sprayer is connected to an external water source through a pipeline; the main control machine is connected to the tracker and the control valve on the sprayer; Step B2: Determine the surface induction heating quenching residence time of the metal workpiece by using the method for determining the quenching residence time as described in any one of claims 1 to 3. t ; Step B3, completing the quenching heating operation and the quenching spray cooling operation on the surface of the metal workpiece; The main control machine is used to control the electromagnetic heating inductor to stay for a certain time during the quenching process. t Internal heating to target quenching temperature T ; At the same time, the main control machine is used to start the turntable to drive the metal workpiece to rotate for one circle to complete the quenching and heating operation on the surface of the metal workpiece; wherein, the tracker is used to obtain the working gap data between the electromagnetic heating sensor and the metal workpiece in real time, and send it to the main control machine; the main control machine controls the mechanical arm to link the electromagnetic heating sensor in real time according to the change of the working gap data, and controls the working gap between the electromagnetic heating sensor and the metal workpiece to be maintained at 2-5mm; The main control machine is used to close the electromagnetic heating sensor and open the control valve on the sprayer to realize the spraying operation; at the same time, the main control machine is used to start the turntable to drive the metal workpiece to rotate one circle to complete the quenching spray cooling operation on the surface of the metal workpiece.

5. The quenching method according to claim 4, characterized in that: The metal workpiece includes any one of a shaft workpiece, a gear, a bearing, a camshaft, a valve and a wear-resistant ring.

6. A surface induction heating device for completing the method for determining the quenching residence time as described in any one of claims 1 to 3, characterized in that: Also included are trackers and sprinklers; A tracker is arranged on the metal workpiece; the sprinkler is arranged on the robot arm; the sprinkler is arranged above the metal workpiece; a control valve is arranged on the sprinkler, and the sprinkler is connected to an external water source through a pipeline; the main control machine is connected to the tracker and the control valve on the sprinkler.

7. The surface induction heating device according to claim 6, characterized in that: The control valve includes a solenoid valve.

8. The surface induction heating device according to claim 6, characterized in that: The main control machine includes a PLC controller.

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