JP2002003934A - Hardening method and hardening apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hardening method in which the surface of a long material is hardened without oxidizing in a simple method. SOLUTION: While injecting non-oxidizing gas 34, 74, 84 from first gas injection tubes 30, a second gas injection tube 70 and a third gas injection tube 80, the surface 14 to be heated is heated to a hardening temperature with a first induction heating coil 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quenching method and a quenching apparatus for sequentially quenching a long material in its longitudinal direction.

[0002]

2. Description of the Related Art As a technique for quenching the surface (surface layer) of a long material, a technique (moving quenching) of sequentially quenching the surface while moving the long material in its longitudinal direction is known. In this moving quenching, generally, the induction heating coil is fixed close to the surface of the long material, and the surface is sequentially heated to the quenching temperature by the induction heating coil while lowering the long material at a predetermined moving speed. Heat is applied to the surface (cooled surface) of the surface that has been heated to the quenching temperature, and the cooled surface is hardened. In the moving quenching, the surface of the long material is sequentially cured in the longitudinal direction in this manner.

However, in the above-described moving quenching, the surface of the long material is heated to the quenching temperature in the air (in the air), so that even if the heating time is short, the surface may be oxidized.

Therefore, a technique (quenching device) for preventing the oxidation of the surface to be heated by injecting an inert gas or a reducing gas onto the surface to be heated and filling the injected gas above the injection position. It has been proposed (JP-A-11-216)
No. 19). In this technique, a housing is provided above an induction heating coil, and the injected gas is filled inside the housing and brought into contact with the surface of a long material. A gas discharge pipe for discharging gas is connected to the housing, and the gas is discharged through the gas discharge pipe. An exhaust gas flow control valve and an electromagnetic valve are attached to the gas exhaust pipe, and the gas is exhausted using these valves.

[0005]

As described above, in the conventional quenching apparatus, in addition to the induction heating coil, a gas injection ring, a housing, a gas exhaust pipe, an exhaust gas flow control valve,
Various components such as a solenoid valve are provided, and the configuration of the quenching device is complicated. For this reason, the handling and the maintenance and inspection are not easily performed, and these may be troublesome operations.

In view of the above circumstances, an object of the present invention is to provide a quenching apparatus and a quenching method that can quench a long material without oxidizing the surface thereof by a simple technique.

[0007]

According to the present invention, there is provided a quenching method in which a long material is sequentially quenched in a longitudinal direction thereof. The surface is sequentially heated to the quenching temperature by moving the induction heating coil and the elongated member relatively in the longitudinal direction of the elongated member by bringing the induction heating coil closer to the quenching temperature. Non-oxidizing gas is injected only to the surface to be heated which is heated by the induction heating coil, and the surface to be heated is covered with the non-oxidizing gas. The present invention is characterized in that a cooling liquid is jetted to a surface to be cooled on the downstream side to harden the surface to be cooled.

[0008] (3) At the same time as injecting the non-oxidizing gas to the surface to be heated, the non-oxidizing gas is also injected to the boundary surface between the surface to be heated and the surface to be cooled. Is also good.

(4) A non-oxidizing gas may also be jetted to an upstream surface of the surface in the moving direction upstream of the surface to be heated, to cover the upstream surface with the non-oxidizing gas.

(5) When the non-oxidizing gas is injected to the upstream surface, the non-oxidizing gas may be injected perpendicular to the upstream surface.

(6) When injecting the non-oxidizing gas into the upstream surface, the non-oxidizing gas is obliquely injected from the front of the surface to be heated toward the upstream surface. The injected non-oxidizing gas may be guided to travel in this oblique direction.

(7) When injecting the cooling liquid onto the surface to be cooled, the injected cooling liquid may be prevented from entering the boundary surface.

Further, (8) a cooling liquid may be sprayed onto the cooling surface while heating the surface to be cooled.

The quenching apparatus according to the present invention is a quenching apparatus for sequentially quenching a long material in a longitudinal direction thereof.
A first induction heating coil through which a cooling liquid flows, which sequentially heats the surface of the long material to the quenching temperature while relatively moving in the longitudinal direction along the long material; (10) the first induction heating coil; 1
A first gas injection pipe for injecting a non-oxidizing gas from the injection port, wherein a gas injection port is disposed in a first heating portion facing the surface of the induction heating coil; and (11) a first induction heating coil. A second induction heating coil disposed on the downstream side in the moving direction, adjacent to the first induction heating coil and through which a coolant flows, for heating the surface; (12) the second induction heating coil; The heating coil is characterized in that the second induction heating coil has a second heating section facing the surface, and a cooling liquid injection port through which a cooling liquid is injected is opened.

Here, (13) the first induction heating coil and the second induction heating coil may be integrally formed.

(14) The first and second induction heating coils formed integrally are separated from each other in the inside, and different types of cooling liquids flow in the respective insides. There may be.

Further, (15) a gas injection port is disposed upstream of the gas injection port of the first gas injection pipe in the moving direction. The gas injection port is disposed upstream of the first gas injection pipe in the movement direction. A second gas injection pipe for injecting a non-oxidizing gas may be provided.

Further, (16) a guide member for guiding the non-oxidizing gas injected from the gas injection port of the second gas injection pipe to the upstream side in the moving direction may be provided.

Further, (17) a prevention member may be provided for preventing the cooling liquid injected from the cooling liquid injection port of the second heating section from entering the upstream side in the moving direction.

(18) The cooling liquid injection port of the second heating section injects a non-oxidizing gas in the injection direction of the cooling liquid injected from the cooling liquid injection port of the second heating section. A gas injection port formed on the upstream side in the movement direction may be provided.

[0021]

Embodiments of the present invention will be described with reference to the drawings. [First Embodiment] Referring to FIGS. 1 and 2, a first embodiment of the present invention will be described.
An embodiment will be described.

FIG. 1 is a cross-sectional view schematically showing a quenching apparatus according to a first embodiment of the present invention cut in a longitudinal direction, and shows only a half (right half in the drawing) of the quenching apparatus. . FIG.
FIG. 2 is a cross-sectional view taken along the line BB of FIG.

The quenching device 10 is a device for sequentially curing the surface of the long material 12 moving in the direction of arrow A (which is an example of the moving direction in the present invention) in the longitudinal direction. The entire shape of the quenching device 10 is ring-shaped, and the quenching device 10 is quenched while the long material 12 passes through the center hole 11. Although the quenching device 10 is substantially symmetrical with respect to the long material 12, only half of the quenching device 10 is shown in FIG. 1 as described above.

The quenching apparatus 10 includes a first induction heating coil 2 for heating the surface (surface layer) of the long material 12 to a predetermined quenching temperature.
0 is provided. A surface (a surface to be heated) 14 of the surface of the long material 12 facing the first induction heating coil 20 is heated to a predetermined quenching temperature. The first induction heating coil 20 is an annular one having a rectangular cross section, and the elongated material 12 passes through the center hole 11 thereof. Also, the first induction heating coil 20
Is formed with a liquid passage (cavity) 22 through which a cooling liquid for cooling the first induction heating coil 20 flows. The liquid passage 22 is connected to an external cooling liquid pipe (not shown).
The cooling liquid is supplied to the liquid path 22, and the cooling liquid is discharged from the liquid path 22. The first induction heating coil 20
Is connected to a high frequency power supply (not shown). In addition, for example, water suitable for cooling the first induction heating coil 20 flows through the liquid passage 22.

In the liquid passage 22 of the first induction heating coil 20,
A plurality of (16 in FIG. 2) first gas injection tubes 30 for injecting the non-oxidizing gas 34 pass. Therefore, the plurality of first gas injection tubes 30 are always cooled by the cooling liquid flowing through the liquid passage 22. In addition, as shown in FIG.
The gas injection tubes 30 are arranged radially around the long material 12.

The gas injection ports 32 of each of the first gas injection pipes 30 are formed in a portion (first heating portion) 21 of the first induction heating coil 20 facing the surface of the long material 12. A portion of the first gas injection pipe 30 around the gas injection port 32 is easily heated by radiant heat from the long material 12. However, since the first gas injection pipe 30 is always cooled by the cooling liquid flowing through the liquid path 22 as described above, the temperature around the gas injection port 32 does not become high. As a result, the first gas injection tube 30 is not damaged by heat, and its life is long.

As described above, since the temperature around the gas injection port 32 does not become high, the gas injection port 32 can be brought close to the surface of the long material 12. In this case, even if the non-oxidizing gas 34 is injected from the gas injection port 32 with a relatively weak force, the injected non-oxidizing gas 34 reaches the surface of the long material 12. Since the momentum of the non-oxidizing gas 34 is weak, the non-oxidizing gas 34 does not rebound to the surface of the long material 12. Therefore, since the surface of the long member 12 is completely covered with the non-oxidizing gas 34, the surface of the long member 12 is not oxidized.

An end of each gas injection pipe 30 opposite to the gas injection port 32 is connected to a gas pipe (not shown). Is supplied to each gas injection tube 30. The non-oxidizing gas 34 supplied to each gas injection pipe 30 is injected from the gas injection port 32 and covers the surface of the long material 12. Note that a non-oxidizing gas refers to a gas containing a reducing gas, an inert gas, or the like, and refers to a gas other than an oxidizing gas.

Downstream of the first induction heating coil 20 in the direction of arrow A, a second
An induction heating coil 40 is provided. The second induction heating coil 40 has a trapezoidal cross section. Inside the second induction heating coil 40, a liquid path 42 through which a cooling liquid 44 flows is provided.
Are formed. In addition, a portion of the second induction heating coil 40 facing the surface of the long material 12 (second heating unit 46)
Are formed with a large number of cooling liquid injection ports 48 from which the cooling liquid 44 is injected. The cooling liquid 44 flowing through the liquid path 42 is jetted from a large number of cooling liquid jet ports 48 to the long material 12. In addition, as the cooling liquid 44, for example, a water-soluble cooling liquid suitable for cooling the long material 12 is used.

The first induction heating coil 20 and the second induction heating coil 40 are integrally formed. Therefore, the liquid passage 22 and the liquid passage 42 are separated by the partition plate 50. This partition plate 50 is a part of the first and second induction heating coils 20 and 40. When the same coolant (for example, water) flows through the liquid passage 22 and the liquid passage 42, the partition plate 50 may not be formed.

As described above, the quenching device 10 includes the first and second induction heating coils 20 and 40 and the first gas injection pipe 30.
Quenching apparatus 10 having a simple structure.
Thus, the surface of the long material 12 can be quenched without being oxidized. Further, since the quenching device 10 has a simple structure, its handling and maintenance and inspection can be easily performed, and troublesome work is not required.

A procedure for quenching a long steel material 12 using the above-described quenching apparatus 10 will be described.

The quenching device 10 is fixed at a predetermined position so that the central hole 11 of the quenching device 10 extends in the vertical direction. Next, a non-oxidizing gas 34 such as a reducing gas or an inert gas is injected from the first gas injection pipe 30. Further, the cooling liquid 44 is injected from the cooling liquid injection port 48. In this state, while the long material 12 is lowered at a predetermined speed through the center hole 11 from above the quenching device 10, the first material is sequentially moved from the lower end of the long material 12 to the first material.
The induction heating coil 20 heats to the quenching temperature. Long material 12
The lowering speed and the heating conditions are appropriately set according to the material.

By injecting the non-oxidizing gas 34 from the first gas injection pipe 30 as described above, the heated surface 14 of the long material 12 is covered with the non-oxidizing gas 34 as shown in FIG. . Therefore, the heated surface 14 does not oxidize even when heated to a high temperature.

Since the long material 12 descends at a predetermined speed, the heated surface 14 heated to the quenching temperature by the first induction heating coil 20 also descends at a predetermined speed, and the cooled surface onto which the cooling liquid 44 is sprayed. It becomes 16. In this case, the surfaces 14 and 16 are heated by the second heating section 46 of the second induction heating coil 40 before the surface 14 and the surface 16 to be cooled are shifted to the surface 16 to be cooled.
As a result, the temperature of the surfaces 14 and 16 does not decrease,
The cooled surface 16 maintained at the quenching temperature can be rapidly cooled. Therefore, the surface to be cooled 16 can be hardened without fail.

As described above, the surface of the long material 12 is rapidly cooled while being sequentially heated, whereby the entire surface is hardened. In this case, since the surface to be heated 14 heated to a high temperature is covered with the non-oxidizing gas 34, no oxide film is formed on the surface. Further, since the gas injection pipe 30 is cooled, the gas injection pipe 30 is not damaged due to heat. Further, since the non-oxidizing gas 34 is injected only to the surface 14 to be heated, the surface of the long material 12 can be quenched by a simple method without oxidizing the surface. Furthermore, since it is a simple method, quenching work can be easily performed.

In the above-described example, the quenching device 10 is fixed and the long material 12 is moved.
May be fixed and the quenching device 10 may be moved. Further, a configuration in which both are simultaneously moved may be adopted. [Second Embodiment] A second embodiment of the present invention will be described with reference to FIG.

FIG. 3 is a cross-sectional view schematically showing a quenching apparatus according to a second embodiment of the present invention, cut in the longitudinal direction, and shows only a half (right half in the drawing) of the quenching apparatus. . In this figure, the same components as those shown in FIG. 1 are denoted by the same reference numerals.

The quenching device 60 is characterized in that it has a second gas injection pipe 70 and a third gas injection pipe 80 as compared with the quenching device 10 of the first embodiment.

The second gas injection pipe 70 passes through the liquid passage 22 of the first induction heating coil 20 and is inclined in a direction approaching the elongated material 12 from the downstream side in the direction of arrow A. Further, like the first gas injection pipe 30 shown in FIG. 2, a plurality of second gas injection pipes 70 are radially arranged. Second gas injection pipe 7
The zero gas injection port 72 is located upstream of the gas injection port 32 of the first gas injection pipe 30 in the direction of arrow A. From this gas injection port 72, a non-oxidizing gas 74 is injected more upstream in the direction of arrow A than the non-oxidizing gas 34 injected from the first gas injection pipe 30.

Accordingly, the non-oxidizing gas 74 is also sprayed on the surface (upstream surface 18) of the long material 12 on the upstream side of the heated surface 14, and the upstream surface 18 is also covered with the non-oxidizing gas 74.
As a result, even if the heat of the heated surface 14 is conducted to the upstream surface 18 and the upstream surface 18 is heated, the upstream surface 18 is not oxidized.

The third gas injection pipe 80 passes through the liquid passage 22 of the first induction heating coil 20 and is inclined in a direction approaching the long material 12 from the upstream side in the direction of arrow A. FIG.
A plurality of third gas injection tubes 80 are radially arranged like the first gas injection tube 30 shown in FIG. The gas injection port 82 of the third gas injection pipe 80 is located downstream of the gas injection port 32 of the first gas injection pipe 30 in the direction of arrow A. From the gas injection port 82, a non-oxidizing gas 34 injected from the first gas injection pipe 30 is located downstream of the non-oxidizing gas 34 in the direction of arrow A (the boundary surface 19 at the boundary between the heated surface 14 and the cooled surface). An oxidizing gas 84 is injected. The direction in which the non-oxidizing gas 84 is injected from the gas injection port 82 depends on the cooling liquid injection port 48.
The direction is the same as the direction in which the cooling liquid 44 is sprayed.

Incidentally, a part of the cooling liquid 44 injected and colliding with the surface to be cooled 16 becomes vapor,
The vapor is prevented from rising by the non-oxidizing gas 84 injected from the nozzle. Therefore, the steam does not come into contact with the heated surface 14 or the boundary surface 19 immediately before the coolant 44 is injected,
These surfaces do not oxidize. Third Embodiment A third embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a cross-sectional view schematically showing the quenching apparatus according to the third embodiment of the present invention cut in the longitudinal direction, and shows only half (the right half in the drawing) of the quenching apparatus. . In this figure, the same components as those shown in FIG. 3 are denoted by the same reference numerals.

The quenching device 90 is characterized in that it has a fourth gas injection pipe 100 as compared with the quenching device 60 of the second embodiment. The fourth gas injection pipe 100 injects the non-oxidizing gas 104 upstream of the non-oxidizing gas 74 injected from the gas injection port 72 in the direction of arrow A. Also, the fourth
A non-oxidizing gas 104 is injected from the gas injection pipe 100 perpendicularly to the upstream surface 18. Therefore, the injected non-oxidizing gas 104 is less likely to be scattered, and the upstream surface 18 can be efficiently covered with the non-oxidizing gas 104. [Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIG.

FIG. 5 is a cross-sectional view schematically showing a quenching apparatus according to a fourth embodiment of the present invention, cut in the longitudinal direction, and shows only a half (right half in the drawing) of the quenching apparatus. . In this figure, the same components as those shown in FIG. 3 are denoted by the same reference numerals.

The quenching device 110 is characterized in that it has an annular guide member 112 when compared with the quenching device 60 of the second embodiment. The guide member 112 is formed as a part of the first induction heating coil 20. Non-oxidizing gas 74 injected from gas injection port 72 of second gas injection pipe 70
Is guided to the upstream side in the direction of arrow A by the guide member 112. Therefore, scattering of the non-oxidizing gas 74 injected from the gas injection port 72 is prevented, and the upstream surface 18 can be efficiently covered with the non-oxidizing gas 74. [Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a cross-sectional view schematically showing a quenching apparatus according to a fifth embodiment of the present invention, cut in the longitudinal direction, and shows only a half (right half in the paper) of the quenching apparatus. . In this figure, the same components as those shown in FIG. 3 are denoted by the same reference numerals.

The quenching device 120 is characterized in that it has an annular prevention member 122 when compared with the quenching device 60 of the second embodiment. The prevention member 122 is made of a thin plate fixed to the second induction heating coil 40.

By the way, the cooling liquid 44 injected from the cooling liquid injection port 48 often collides with the surface to be cooled 16 and scatters. Further, a part of the cooling liquid 44 colliding with the surface to be cooled 16 may become steam. Even if the cooling liquid 44 scatters or turns into steam in this way, since the prevention member 122 is provided, these cannot enter the boundary surface 19 or the heated surface 14. That is, the prevention member 122 prevents the coolant 44 that has scattered or turned into steam from entering the upstream side in the direction of arrow A. Therefore, the boundary surface 19 and the heated surface 14
Oxidation is more reliably prevented.

[0051]

As described above, according to the quenching method of the present invention (the quenching method according to claim 1), the heated surface is covered with the non-oxidizing gas, so that the heated surface is not oxidized. Therefore, since the heated surface to be heated does not oxidize, the surface of the long material can be hardened without being oxidized. Further, since the non-oxidizing gas is injected only to the surface to be heated, it can be quenched by a simple method without oxidizing the surface of the long material. Furthermore, since it is a simple method, quenching work can be easily performed.

Here, when simultaneously injecting the non-oxidizing gas onto the surface to be heated and simultaneously injecting the non-oxidizing gas into the boundary surface between the surface to be heated and the surface to be cooled,
Since the non-oxidizing gas injected to the boundary surface blocks the cooling liquid, even if the injected cooling liquid scatters, it does not enter the surface to be heated. Therefore, oxidation of the long material can be more reliably prevented.

In the case where the non-oxidizing gas is also jetted to the upstream surface in the moving direction of the surface to be heated from the surface to be heated and the upstream surface is covered with the non-oxidizing gas, the upstream surface is also used. Since the non-oxidizing gas is injected and the upstream surface is covered with the non-oxidizing gas, the upstream surface is not oxidized even if the heat of the heated surface is conducted to the upstream surface and the upstream surface is heated. Further, when the non-oxidizing gas is simultaneously injected to both the boundary surface and the upstream surface, the non-oxidizing gas injected to the surface to be heated is confined by the non-oxidizing gas injected at the same time. As a result, the surface to be heated is more reliably covered with the non-oxidizing gas.

Further, when the non-oxidizing gas is injected perpendicular to the upstream surface when the non-oxidizing gas is injected to the upstream surface, the upstream surface can be efficiently covered with the non-oxidizing gas.

Further, when the non-oxidizing gas is injected to the upstream surface, the non-oxidizing gas is injected obliquely from the front of the surface to be heated toward the upstream surface, and the non-oxidizing gas is injected obliquely. When the non-oxidizing gas is guided to travel in this oblique direction, the non-oxidizing gas is prevented from scattering and the upstream surface can be more efficiently covered with the non-oxidizing gas.

Furthermore, if the injected coolant is not allowed to enter the interface when the coolant is injected onto the surface to be cooled, the coolant does not enter the interface, so that the oxidation of the interface is more reliable. Is prevented.

Further, in the case where the cooling liquid is sprayed onto the cooling surface while heating the surface to be cooled, the temperature does not decrease during the transition from the surface to be cooled to the surface to be cooled. The surface to be cooled can be rapidly cooled. Therefore, the surface to be cooled can be hardened without fail.

Further, according to the quenching apparatus of the present invention (the quenching apparatus according to claim 8), the surface of the first gas injection pipe is heated by the first induction heating coil. Since the non-oxidizing gas is injected from the injection port, the surface to be heated is covered with the non-oxidizing gas. Therefore, the heated surface does not oxidize even when heated to a high quenching temperature. The heated surface to be heated moves and is heated by the second induction heating coil, and is cooled by the cooling liquid injected from the cooling liquid injection port of the second heating unit. Therefore, the quenching temperature when heated by the first induction heating coil is maintained on the surface to be heated, and the coolant is sprayed onto the surface to be heated at the quenching temperature. As a result, the heated surface is rapidly cooled from the quenching temperature accurately. Thus, the quenching apparatus of the present invention can quench the surface of the long material without oxidizing the surface. In addition, since the quenching device includes the first and second induction heating coils and the first gas injection pipe, the quenching device having a simple structure can be quenched without oxidizing the surface of the long material. Further, since the quenching device has a simple structure, handling and maintenance and inspection thereof can be easily performed, and troublesome work is not required.

Here, when the first induction heating coil and the second induction heating coil are integrally formed, a quenching device having a simpler structure can be obtained.

In the case where the first and second induction heating coils are integrally formed, the insides thereof are partitioned from each other, and different types of cooling liquid are flowing in the respective insides. Inside the first induction heating coil,
A cooling liquid suitable for cooling the first induction heating coil can flow. On the other hand, a coolant suitable for cooling the surface of the long material can flow through the second induction heating coil.

Further, the quenching apparatus further comprises a gas injection port disposed upstream of the gas injection port of the first gas injection pipe in the moving direction, the gas injection port being located upstream of the first gas injection pipe in the movement direction. When a second gas injection pipe for injecting a non-oxidizing gas is provided on the side, a surface (upstream surface) on the upstream side of the surface to be heated, which is heated by the first induction heating coil, of the surface of the long material Since the non-oxidizing gas is also injected to cover the upstream surface with the non-oxidizing gas, the heat of the surface to be heated is conducted to the upstream surface and the upstream surface is not oxidized even if the upstream surface is heated.

Further, when the quenching device is provided with a guide member for guiding the non-oxidizing gas injected from the gas injection port of the second gas injection pipe to the upstream side in the moving direction, the quenching device may be provided with a non-oxidizing gas. The upstream surface can be efficiently covered with a non-oxidizing gas by preventing the scattering of gas.

Furthermore, when the quenching device is provided with a preventing member for preventing the cooling liquid injected from the cooling liquid injection port of the second heating section from entering the upstream side in the moving direction, the cooling liquid Does not enter the heated surface, so that the heated surface can be prevented from being oxidized by the cooling liquid or its vapor.

Further, the quenching device is configured to inject a non-oxidizing gas in a jet direction of the cooling liquid jetted from the cooling liquid jet port of the second heating section. In the case where a gas injection port formed on the upstream side in the moving direction is also provided, the non-oxidizing gas injected from the gas injection port on the upstream side receives the coolant injected from the coolant injection port of the second heating unit. , The coolant does not enter the upstream side in the moving direction. Therefore, it is possible to prevent the surface to be heated from being oxidized by the cooling liquid or its vapor.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a quenching apparatus according to a first embodiment of the present invention, cut in a longitudinal direction, and shows only a half (right half in the drawing) of the quenching apparatus.

FIG. 2 is a cross-sectional view taken along the line BB of FIG.

FIG. 3 is a cross-sectional view schematically showing a quenching apparatus according to a second embodiment of the present invention, which is cut in a longitudinal direction, and shows only a half (right half in the drawing) of the quenching apparatus.

FIG. 4 is a cross-sectional view schematically showing a quenching device according to a third embodiment of the present invention cut in a longitudinal direction, and shows only a half (right half in the drawing) of the quenching device.

FIG. 5 is a cross-sectional view schematically showing a quenching apparatus according to a fourth embodiment of the present invention cut in a longitudinal direction, and shows only a half (right half in the paper) of the quenching apparatus.

FIG. 6 is a cross-sectional view schematically showing a quenching apparatus according to a fifth embodiment of the present invention, cut in a longitudinal direction, and shows only a half (right half in the drawing) of the quenching apparatus.

[Explanation of symbols]

 10, 60, 90, 110, 120 Quenching device 14 Heated surface 16 Cooled surface 18 Upstream surface 19 Boundary surface 20 First induction heating coil 21 First heating unit 30 First gas injection pipe 40 Second induction heating coil 46 Second heating section 70 Second gas injection pipe 112 Guide member 122 Prevention member

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Jun Fujie 84-10 Jiumida, Nishisakai-machi, Kariya-shi, Aichi F-term in Takamami Nami Thermal Smelting Co., Ltd. (Reference) 3K059 AA09 AB09 4K042 AA14 BA14 DA01 DB01 DD04 DF01 EA01

Claims (14)

[Claims] 1. A quenching method for sequentially quenching a long material in a longitudinal direction thereof, wherein an induction heating coil is brought close to the surface of the long material, and the induction heating coil and the long material are combined with each other. While sequentially heating the surface to the quenching temperature by moving it relatively in the longitudinal direction, the non-oxidizing gas is injected only to the surface to be heated of the surface heated by the induction heating coil. Covering the surface to be heated with a non-oxidizing gas, and curing the surface to be cooled by injecting a cooling liquid onto the surface to be cooled in the movement direction downstream of the surface to be heated among the surfaces. Quenching method. 2. A non-oxidizing gas is injected onto the surface to be heated, and simultaneously, a non-oxidizing gas is injected onto a boundary surface between the surface to be heated and the surface to be cooled. Claim 1
Quenching method. 3. A non-oxidizing gas is sprayed on an upstream surface of the surface on the upstream side in the moving direction from the surface to be heated, and the upstream surface is covered with the non-oxidizing gas. 3. The quenching method according to 1 or 2. 4. The quenching method according to claim 3, wherein a non-oxidizing gas is injected perpendicular to the upstream surface when the non-oxidizing gas is injected to the upstream surface. 5. When injecting a non-oxidizing gas into the upstream surface, a non-oxidizing gas is obliquely injected from the front of the surface to be heated toward the upstream surface, and the non-oxidizing gas is injected obliquely. The quenching method according to claim 3, wherein the oxidizing gas is guided so as to proceed in the oblique direction. 6. The cooling liquid according to claim 1, wherein when the cooling liquid is injected to the surface to be cooled, the injected cooling liquid does not enter the boundary surface. Quenching method. 7. The quenching method according to claim 1, wherein a cooling liquid is injected onto the cooling surface while heating the surface to be cooled. 8. A quenching apparatus for sequentially quenching a long material in a longitudinal direction thereof, wherein the surface of the long material is sequentially quenched while moving relatively along the long material in the longitudinal direction. A first induction heating coil through which a cooling liquid flows, and a non-oxidizing gas from the injection port, wherein a gas injection port is arranged in a first heating portion of the first induction heating coil facing the surface. A first gas injection pipe for injecting a liquid, heating the surface, which is disposed adjacent to the first induction heating coil downstream of the first induction heating coil in the moving direction and in which a cooling liquid flows inside A second induction heating coil having a cooling liquid injection opening for injecting a cooling liquid into a second heating section facing the surface of the second induction heating coil. A quenching device characterized by the following. 9. The quenching apparatus according to claim 8, wherein the first induction heating coil and the second induction heating coil are formed integrally. 10. The first and second induction heating coils which are integrally formed have their interiors partitioned from each other, and different types of coolant are flowing inside each of them. The quenching device according to claim 9, wherein 11. A gas injection port is arranged upstream of the gas injection port of the first gas injection pipe in the moving direction, and is non-oxidizing upstream of the first gas injection pipe in the movement direction. The quenching device according to claim 8, 9 or 10, further comprising a second gas injection pipe for injecting gas. 12. The firing apparatus according to claim 11, further comprising a guide member for guiding a non-oxidizing gas injected from a gas injection port of the second gas injection pipe to an upstream side in the moving direction. Input device. 13. The apparatus according to claim 8, further comprising a prevention member for preventing a coolant injected from a coolant injection port of the second heating unit from entering the upstream side in the moving direction. The quenching device according to any one of the above. 14. A non-oxidizing gas is jetted in a jet direction of a coolant injected from a coolant injection port of the second heating unit.
The quenching according to any one of claims 8 to 13, further comprising a gas injection port formed on the upstream side in the moving direction of the cooling liquid injection port of the second heating unit. apparatus.