JPH09303620A - Method for removing anticorrosion layer of steel pipe coated with anticorrosion layer, heating device for removing the anticorrosion layer, and tool for removing the anticorrosion layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate separating work of an anti-corrosion layer in an outside regardless of a pipe diameter, and the like by winding a heating coil around the outer peripheral surface of an anti-corrosion layer, and separating the anti-corrosion layer after a steel pipe is heated by induction heating, in the case where the anti-corrosion layer is separated in the steel pipe covered by the anti-corrosion layer capable of separating by heating. SOLUTION: In a steel layer 11 provided with at anti-corrosion layer 12 made of polyethylene covered layer, two notches 14 are formed in a circumferential direction along the whole of the circumference of the layer 12 at both end positions of a separating range 13, and one notch 15 is formed in a pipe shaft direction between both notches 14. The steel pipe heating work coil (heating coil) 21 of a high frequency induction heating device is wound around the outer peripheral surface of the layer 12 which will be separated, exchange current for induction heating is applied on the heating coil 21 through a power supply control board 22. A steel pipe 11 is inductively heated by the heating coil 21, adhesive agent for adhering the steel pipe 11 and the layer 12 and the layer 12 are softened by heating by heat conduction from the steel pipe 11 so as to facilitate separation of the layer 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for peeling an anticorrosion layer when cutting or making a welded joint in the middle of the pipe in the pipe construction of the anticorrosion layer coated steel pipe used for a gas pipe or the like. The present invention relates to a method for removing an anticorrosion layer of a steel pipe coated with an anticorrosion layer, a heating device for removing the anticorrosion layer, and a tool for removing the anticorrosion layer.

[0002]

2. Description of the Related Art For example, a gas pipe or the like is cut to a predetermined length depending on the shape of roads, buildings, etc. and obstacles,
Often connected through bends.

In this case, the long tube is cut into a predetermined length by a general gas cutting machine, but it is necessary to remove the polyethylene-coated anticorrosion layer at the cut portion before cutting. At this time, the polyethylene-coated anticorrosion layer is very hard, and its adhesion to the steel pipe is strong.

Therefore, it is generally necessary to heat the anticorrosion layer to soften it and to reduce the adhesive strength.

Therefore, the gas conduit or the like is heated by the gas burner or the propane burner, and the anticorrosion layer is softened by the heat conduction.

At this time, when a fire such as a burner is directly applied to the anticorrosion layer coated with polyethylene, the polyethylene coating is burned, so that in a large diameter pipe, an operator enters the pipe,
The steel pipe is heated by the burner.

Then, when a certain temperature is reached, a cut is made from the outside to the polyethylene-coated anticorrosion layer with a special cutter, and the end of the anticorrosion layer is manually pulled and pulled from the steel pipe.

[0008]

Therefore, a person who heats with the burner must handle the burner in a poor environment inside the steel pipe, which causes a problem in the working environment.

Further, it is not easy to uniformly heat the entire area of the anticorrosion layer to be peeled off by heating with a burner,
Therefore, when peeling the anticorrosion layer, an extremely large amount of labor is required due to the nonuniform heating temperature.

The present invention has been made in view of the above points, and provides a method for peeling an anticorrosion layer, which enables the work of peeling an anticorrosion layer from a steel pipe coated with an anticorrosion layer to be easily performed outside regardless of the pipe diameter or the like. In addition, we provide a heating device for peeling the anticorrosion layer that can easily heat the anticorrosion layer-coated steel pipe outside the tube and heat the entire area of the anticorrosion layer to a uniform temperature, so that the anticorrosion layer can be formed without much labor. It is an object of the present invention to provide a tool for peeling an anticorrosion layer that can be easily peeled off.

[0011]

According to a first aspect of the present invention, there is provided a method of peeling an anticorrosion layer in a steel pipe covered with an anticorrosion layer capable of being peeled by heating, in which the outer peripheral surface of the anticorrosion layer is to be peeled. A step of winding a heating coil around, and a step of heating the steel pipe by induction heating using the heating coil,
A method of peeling an anticorrosion layer from a steel pipe coated with an anticorrosion layer, comprising the step of stripping the anticorrosion layer heated by heat conduction from the steel pipe.

Then, the steel pipe is heated to a predetermined appropriate temperature by induction heating by a heating coil wound around the outer peripheral surface of the anticorrosion layer to soften the heated anticorrosion layer by heat conduction from the steel pipe and to the steel pipe. The adhesive strength is reduced to make it easier to peel off than the steel pipe, and then the anticorrosion layer is peeled off with a tool or manually.

According to a second aspect of the present invention, in the method for peeling an anticorrosion layer of a steel pipe coated with an anticorrosion layer according to the first aspect, in the step of heating the steel pipe, winding of a heating coil is performed according to the diameter and the thickness of the steel pipe. It is a method of attaching and adjusting the electric output.

By this adjusting method, the heating temperature of the steel pipe by the heating coil is adjusted according to the diameter of the steel pipe,
The anticorrosion layer adhered to the steel pipe is heated by heat conduction to a temperature at which it is most likely to peel off.

According to a third aspect of the present invention, in the method for removing an anticorrosion layer of a steel pipe coated with an anticorrosion layer according to any one of the first and second aspects, an adhesive and an anticorrosion layer for adhering the anticorrosion layer and the steel pipe to each other. This is a method of moving to a step of peeling the anticorrosion layer from the steel pipe when the steel has softened.

Then, the adhesive and the anticorrosion layer are softened by the dielectric heating by the heating coil and the heating by the heat conduction, the adhesive effect of the adhesive is weakened, and the anticorrosion layer has flexibility which is convenient for peeling work. Above, the anticorrosion layer is peeled off from the steel pipe.

According to a fourth aspect of the invention, in the method for peeling an anticorrosion layer of a steel pipe coated with an anticorrosion layer according to any one of the first to third aspects, one end portion and the other end portion in the pipe axial direction in the peeling region of the anticorrosion layer. In this method, a notch in the circumferential direction is made over the entire circumference, and a notch in the tube axis direction is made at the separation start position between the notches in the circumferential direction.

Then, a cut portion in the axial direction of the anticorrosion layer is cut and raised, and the peeling work is started from this portion,
The anticorrosion layer having a constant width is peeled off along the entire circumference along the circumferential notch.

According to a fifth aspect of the present invention, in the method for peeling an anticorrosion layer of a steel pipe coated with an anticorrosion layer according to any one of the first to fourth aspects, the heating coil is wound around the outer peripheral surface outside the exfoliation region of the anticorrosion layer. This is a method in which induction heating for keeping heat is continued while peeling off the attached enemies and peeling the anticorrosion layer.

Then, induction heating for keeping heat by the heating coil wound around the outer surface of the peeling area of the anticorrosion layer prevents solidification of the adhesive due to cooling during the peeling operation of the anticorrosion layer.

The invention described in claim 6 is the method for removing the anticorrosion layer of the steel pipe covered with the anticorrosion layer according to any one of claims 1 to 5, wherein the anticorrosion layer is a polyethylene coating layer.

The invention described in claim 7 is a heating device for peeling off an anticorrosion layer in a steel pipe coated with an anticorrosion layer which can be peeled by heating, wherein the outer peripheral surface of the anticorrosion layer to be peeled is A heating device for peeling an anticorrosion layer of a steel pipe covered with an anticorrosion layer, comprising: a heating coil to be wound; and a power supply control panel for supplying an alternating current for induction heating to the heating coil.

By supplying an alternating current for induction heating from the power control board to the heating coil, the steel pipe is induction-heated when the anticorrosion layer is peeled from the steel pipe, and the anticorrosion layer is heated by heat conduction. A heating coil is evenly wound around the peeled region of the anticorrosion layer to uniformly heat the entire region.

The invention described in claim 8 is a tool for peeling an anticorrosion layer in a steel pipe covered with an anticorrosion layer, wherein a slit for inserting a peeling cut-raised portion of the anticorrosion layer is an axis. A tool for peeling an anticorrosion layer of a steel pipe covered with an anticorrosion layer, comprising: a tubular tool body provided in a direction; and an operating body for rotating the tool body.

Then, by inserting the cut-and-raised part for peeling the anticorrosion layer into the slit and rotating the tool main body by the operating body, the anticorrosion layer is wound around the outer peripheral surface of the tool main body, and the lever principle is used. Use to remove the anticorrosion layer from the steel pipe.

According to a ninth aspect of the present invention, in the tool for peeling an anticorrosion layer of an anticorrosion layer-coated steel pipe according to the eighth aspect, at least one end portion of the tool body has a fitting portion that fits with the operating body. It is a tool with a cap detachably attached.

If it is not easy to insert the cut-and-raised portion for peeling of the anticorrosion layer from the front side of the slit, the cap may be removed from the end of the tool body into the slit. Insert the cut-and-raised part for peeling of the anticorrosion layer.

The invention described in claim 10 is the invention according to claim 8.
In the tool for peeling the anticorrosion layer of the anticorrosion layer-coated steel pipe according to any one of 1 and 2, the operation body is a wrench with a ratchet.

Then, the tool body is rotated in one direction by reciprocally rotating while the ratchet wrench is attached to the fitting portion of the cap to wind the anticorrosion layer around the outer peripheral surface of the tool body.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a long steel pipe coated with an anticorrosion layer. The anticorrosion layer 12 adhered to the outer peripheral surface of the steel pipe 11 is a polyethylene coating layer.

When attempting to cut the middle portion of the steel pipe 11, a region having a total length of about 30 cm in the pipe axial direction with the cut portion as the center is defined as a peeling region 13 of the anticorrosion layer 12, and the peeling region 13 has both end positions. Two cuts 14 in the circumferential direction are previously made by a cutter or the like over the entire circumferential surface of the anticorrosion layer 12, and one cut 15 is made in the pipe axis direction between the cuts 14 at these two places.

The notch 14 in the circumferential direction and the notch 15 in the tube axis direction may be made immediately after the heating step described later. Immediately after the heating step, the anticorrosion layer 12 has softened,
There is an advantage that it is easy to make a cut.

FIG. 2 shows a high frequency induction heating device. This high-frequency induction heating device includes a work coil for heating a steel pipe (hereinafter referred to as a heating coil 21) wound around the outer peripheral surface of the anticorrosion layer 12 to be peeled, and an alternating current for induction heating to the heating coil 21. It comprises a power supply control board 22 such as a high-frequency inverter control board to be supplied, an input cable 23 connected to the power supply control board 22, and an output cable 24 connecting the power supply control board 22 and the heating coil 21. The heating coil 21 is a peeling area.
Wrap it so that it slightly protrudes from 13.

This high frequency induction heating device is equipped with a heating coil 21.
The steel pipe 11 is induction-heated by the above to soften the adhesive for adhering the steel pipe 11 and the anticorrosion layer 12 and the anticorrosion layer 12 by heating by heat conduction from the steel pipe 11 to facilitate peeling of the anticorrosion layer 12.

There is a range of suitable peeling temperature for softening the anticorrosion layer 12 and the like. In order to obtain this suitable temperature range, the heating coil 21 is adjusted according to the diameter and thickness of the steel pipe 11.
Winding method (number of turns and winding density) and power control panel 22
Since it is necessary to adjust the electrical output of the heating coil 21, the winding method and the like of the heating coil 21 are determined by preliminarily storing data on the relationship between them.

Alternatively, a thermometer sensor such as a thermocouple (not shown) is installed on the inner surface of the steel pipe 11 or the outer surface of the anticorrosion layer 12,
It is also possible to monitor the heating temperature of the steel pipe 11, and further, by interlocking such a thermometer sensor and the output of the power supply control panel 22, the heating temperature can be automatically controlled to a set value. Is also possible.

FIG. 3 shows the principle of induction heating, and an alternating magnetic flux 25 generated by an alternating current supplied from the power supply control panel 22.
Penetrates the steel pipe 11 which is a conductor, induces an extremely high density eddy current in the steel pipe 11 (this is called electromagnetic induction), and the Joule heat generated by resistance loss or hysteresis loss of the eddy current causes steel pipe 11 is heated directly. The main frequency used for this dielectric heating is 50 Hz or 60 Hz to 450 Hz of the commercial frequency,
High frequencies may also be used.

By such induction heating by the heating coil 21 wound around the outer peripheral surface of the anticorrosion layer 12, the steel pipe 11 is directly heated to a predetermined appropriate temperature, and the anticorrosion layer 12 conducts heat from the steel pipe 11. To soften the anticorrosion layer 12 and simultaneously reduce the adhesive strength of the adhesive agent that adheres the anticorrosion layer 12 to the steel pipe 11. As a result, the anticorrosion layer 12 becomes
Make it easier to peel off.

As shown in FIG. 4, when heating to a constant temperature is completed, the power is turned off, and the heating coil 21 is shifted in the left and right directions in a wound state so as to divide the heating coil 21 in two, to prevent corrosion in advance. Move to the outside of the left and right incisions 14 made in layer 12. It should be noted that the heating coil 21 is connected by a connector 26 at the central portion, and if the heating coil 21 interferes with the work during the peeling work, it is preferable to disconnect the connector 26.

Then, along the circumferential notch 14, the starting end portion of the anticorrosion layer 12 which is to be peeled from the notch 15 in the axial direction of the pipe is cut several cm by a cutting and raising tool having a flat tip.
It is cut and raised, and this is used as a peeling cut and raised portion 12a.

As shown in FIG. 5, a tool 30 for peeling the anticorrosion layer is set in the cut-and-raised portion 12a for peeling of the anticorrosion layer 12, and the polyethylene coated anticorrosion layer 12 and the adhesive are softened in a temperature range. The anticorrosion layer 12 promptly so that the work is completed in
Is peeled off from the steel pipe 11. Reference numeral 11a is a steel pipe portion from which the anticorrosion layer 12 is peeled off.

As shown in FIGS. 6 and 7, the anticorrosion layer peeling tool 30 has a slit 32 for inserting the peeling cut-and-raised portion 12a of the anticorrosion layer 12 into a cylindrical tool body 31. It is provided in the axial direction from the left end of the main body 31, and a cap 33 is integrally provided at the right end of the tool main body 31.

A male screw 34 is provided on the outer peripheral surface of the left end of the tool body 31.
A screw cap 35 is detachably attached to the male screw 34 by screwing a female screw 36 formed on the inner peripheral surface thereof.

On the outer side surfaces of these caps 33, 35, projecting fitting portions 37 having a hexagonal or quadrangular cross section are integrally projected. The tool body 31
Wrench with ratchet 41 as an operating body for rotating
Socket 42 is fitted. This wrench 41 has a handle
A check claw mechanism is built in the tip ratchet portion 44 of 43, and the rotation of the socket 42 is limited to only one direction by this check claw mechanism.

Then, the anticorrosion layer is formed on the slit 32 of the tool body 31.
When inserting the peeling cut-and-raised portion 12a of 12, the peeling cut-and-raised portion 12a may be inserted from the front into the slit 32 of the tool body 31 with the left and right caps 33 and 35 attached. With the left-hand screw cap 35 removed from the male screw 34 of the tool body 31, by inserting the peeling cut-and-raised portion 12a of the anticorrosion layer 12 into the slit 32 from the left end of the tool body 31,
Even if the peeling cut-and-raised portion 12a of the anticorrosion layer 12 is deformed, it can be easily inserted into the slit 32.

In such a case, after the cut-and-raised portion 12a for peeling of the anticorrosion layer 12 is inserted into the slit 32, the screw cap 35
By attaching the sockets 42 of the wrench 41 with ratchets on both sides to the protruding fitting portions 37 of the caps 33 and 35, and simultaneously reciprocally rotating the handles 43 of the wrench 41 on both sides in the same direction. The tool body 31 is rotated only in the anticorrosion layer winding direction by the check claw mechanism of the tip ratchet portion 44.

As a result, the anticorrosion layer peeling tool 30 peels the anticorrosion layer 12 from the steel pipe 11 using the lever principle while winding the anticorrosion layer 12 on the outer peripheral surface of the tool body 31,
The outer peripheral surface of the steel pipe 11 is rotated once to complete the peeling work.

In such peeling work, the peeling aptitude temperature suitable for softening the adhesive agent for adhering the steel pipe 11 and the anticorrosion layer 12 and the anticorrosion layer 12 itself is 100 as a result of the experiment.
~ 110 ℃, the time required for peeling is 600A pipe diameter
In this case, it is about 5 minutes, and the heating temperature of the steel pipe 11 can be kept within the proper temperature range (100 to 110 ° C.) during this working time. Needless to say, the steel pipe 11 does not melt in this temperature range.

For example, FIG. 8 shows the relationship between the heating and cooling curves of the steel pipe 11 and the working time when the pipe diameter is 600 A. The steel pipe temperature is 100 during the time of 4 minutes and 50 seconds required for the peeling work. It could be kept in the range of ~ 110 ° C.

As shown in FIG. 4, the heating coil 21 is wound from the peeling region 13 of the anticorrosion layer 12 to the outer peripheral surface outside the notches 14 on both sides, and induction heating for heat retention is continued during the peeling work. By doing so, the steel pipe 11 can be maintained at a constant appropriate temperature.

As described above, the heating according to the present invention is applied to the anticorrosion layer.
Since induction heating is performed on the outer surface of the tube 12, it is not necessary for a worker to enter the tube and heat the steel tube 11 from the inside by the flame of the gas burner as in the conventional case.

Further, the peeling work is carried out by the tool 30 for peeling the anticorrosion layer.
By using, it is possible to easily finish in a short time without requiring a great labor of a worker. Further, the relationship between working time and temperature control can be easily established by accumulating experience and data, and a series of work for heating and peeling the anticorrosion layer 12 from the anticorrosion layer-coated steel pipe can be reasonably performed.

[0054]

According to the invention described in claim 1, a heating coil is wound around the outer peripheral surface of the anticorrosion layer to be peeled off, and the steel pipe is heated by induction heating using the heating coil to conduct heat from the steel pipe. By the method of peeling the anticorrosion layer heated by, the work of peeling the anticorrosion layer from the anticorrosion layer-coated steel pipe can be easily performed outside regardless of the pipe diameter.

According to the second aspect of the invention, in the step of heating the steel pipe, the diameter of the steel pipe is adjusted by adjusting the winding method of the heating coil and the electric output according to the diameter and thickness of the steel pipe. The heating temperature by the heating coil can be adjusted to a temperature at which the anticorrosion layer is most easily peeled off according to the conditions, and the anticorrosion layer can be easily peeled off from the steel pipe.

According to the third aspect of the invention, when the adhesive for adhering the anticorrosion layer and the steel pipe and the anticorrosion layer are softened, the process proceeds to the step of peeling the anticorrosion layer from the steel pipe. Can weaken the adhesive effect of
The anticorrosion layer can be easily exfoliated from the steel pipe by providing the anticorrosion layer with a flexibility that is convenient for exfoliation work.

According to the fourth aspect of the invention, notches are formed in the peeling region of the anticorrosion layer in the pipe axial direction at one end and the other end in the pipe axial direction, and a cut is made in the pipe axial direction at the peeling start position. In addition, the peeling work can be easily started by cutting and raising the cut portion of the anticorrosion layer in the pipe axis direction, and the anticorrosion layer having a constant width can be reliably peeled over the entire circumference along the circumferential cut.

According to the fifth aspect of the invention, the heating coil is wound around the outer peripheral surface outside the peeling region of the anticorrosion layer, and induction heating for heat retention is continued during the peeling of the anticorrosion layer. It is possible to prevent the solidification of the adhesive and the like due to cooling during the layer peeling work, and to easily peel the anticorrosion layer to the end.

According to the sixth aspect of the invention, when the anticorrosion layer is a polyethylene coating layer, when the anticorrosion layer is peeled off from the steel pipe, it is particularly effective in terms of softening and easy peeling of the anticorrosion layer.

According to the seventh aspect of the invention, the heating device for peeling the anticorrosion layer supplies an alternating current for induction heating from the power supply control panel to the heating coil wound around the outer peripheral surface of the anticorrosion layer. In peeling the anticorrosion layer, the heating work of the steel pipe and the anticorrosion layer can be easily performed outside the pipe,
Workability can be improved, and by uniformly winding the heating coil around the anticorrosion layer region to be peeled, the entire region can be uniformly and efficiently heated to facilitate peeling.

According to the eighth aspect of the present invention, an anticorrosion layer is provided in which a cylindrical tool body provided with a slit for inserting the peeling cut-and-raised part of the anticorrosion layer in an axial direction is rotated by an operating body. While the anticorrosion layer is wound on the outer peripheral surface of the tool body by a simple operation of inserting the peeling cut-and-raised part of the anticorrosion layer into the slit with the peeling tool and rotating the tool body with the operating body. By using the lever principle, the anticorrosion layer can be easily peeled from the steel pipe with a small amount of labor.

According to the ninth aspect of the invention, since the cap having the fitting portion for fitting the operating body is detachably attached to at least one end of the tool body, the cut-and-raised portion for peeling the anticorrosion layer is formed. Even if it is not easy to insert it from the front of the slit because it is deformed, it is easy to make the cut-and-raised part for peeling the anticorrosion layer from the one end of the tool body in the slit with the cap removed. The operability can be improved.

According to the tenth aspect of the invention, since the operating body is a wrench with a ratchet, the tool body is unidirectionally operated by reciprocally rotating the wrench with a ratchet while it is attached to the fitting portion of the cap. The anticorrosion layer can be easily wound up by rotating it to, and the operability can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing an anticorrosion layer-coated steel pipe according to the present invention.

FIG. 2 is a schematic view showing an embodiment of a heating device for peeling an anticorrosion layer according to the present invention.

FIG. 3 is an explanatory view showing the principle of induction heating by the above heating device.

FIG. 4 is a front view showing a state in which a peeled region of an anticorrosion layer after induction heating is cut and raised.

FIG. 5 is a perspective view showing a state in which a part of the anticorrosion layer is started to be peeled by the anticorrosion layer peeling tool according to the present invention.

6A is a perspective view showing an embodiment of a tool for peeling an anticorrosion layer according to the present invention, and FIG. 6B is a perspective view showing a screw cap thereof.

FIG. 7 is a front view showing a state in which a part of the above tool is broken.

FIG. 8 is a graph showing temperature characteristics of a steel pipe heated by a heating device according to the present invention.

[Explanation of symbols]

 11 Steel pipe 12 Anticorrosion layer 12a Peeling part for peeling 13 Peeling region 14 Circumferential notch 15 Pipe axial notch 21 Heating coil 22 Power control panel 31 Tool body 32 Slits 33, 35 Cap 37 Fitting part 41 As an operating body Wrench with ratchet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Hibi 593-5, Miyamae, Fujisawa-shi, Kanagawa Prefecture (72) Inventor Mitsuo Sato 487-31 Hirose, Togane-shi, Chiba Prefecture

Claims (10)

[Claims] 1. A method of peeling a corrosion-resistant layer of a steel pipe covered with a corrosion-resistant layer capable of peeling by heating, wherein a step of winding a heating coil around the outer peripheral surface of the corrosion-resistant layer to be peeled, and a heating coil are used. A method for peeling an anticorrosion layer from a steel pipe coated with an anticorrosion layer, comprising: a step of heating the steel pipe by induction heating; and a step of stripping the anticorrosion layer heated by heat conduction from the steel pipe. 2. The anticorrosion layer of the anticorrosion layer-coated steel pipe according to claim 1, wherein, in the step of heating the steel pipe, the winding method and the electric output of the heating coil are adjusted according to the diameter and the thickness of the steel pipe. Peeling method. 3. The method according to claim 1, wherein when the adhesive for adhering the anticorrosion layer and the steel pipe and the anticorrosion layer are softened, the step of separating the anticorrosion layer from the steel pipe is performed. A method for removing an anticorrosion layer from a steel pipe coated with the anticorrosion layer as described above. 4. A notch in the circumferential direction is formed at one end and the other end in the pipe axial direction in the peeling region of the anticorrosion layer over the entire circumference, and a notch in the pipe axial direction is made at a peeling start position between the notches in the circumferential direction. Claim 1 characterized by the above.
4. The method for removing an anticorrosion layer of a steel pipe coated with an anticorrosion layer according to any one of 3 to 3. 5. A heating coil is wound around the outer peripheral surface outside the peeling region of the anticorrosion layer, and induction heating for heat retention is continued during the peeling of the anticorrosion layer. The method for peeling an anticorrosion layer of a steel pipe coated with an anticorrosion layer according to any one of claims 1. 6. The method for removing an anticorrosion layer from a steel pipe coated with an anticorrosion layer according to claim 1, wherein the anticorrosion layer is a polyethylene coating layer. 7. A heating device for peeling an anticorrosion layer of a steel pipe coated with an anticorrosion layer capable of being peeled by heating, comprising: a heating coil wound around an outer peripheral surface of the anticorrosion layer to be peeled; A heating device for peeling an anticorrosion layer of a steel pipe coated with an anticorrosion layer, comprising: a power supply control panel that supplies an alternating current for induction heating to a heating coil. 8. A tool for peeling off an anticorrosion layer in a steel pipe covered with an anticorrosion layer, which is a tubular shape in which a slit for inserting a cut-and-raised portion for peeling of the anticorrosion layer is provided in an axial direction. A tool for peeling an anticorrosion layer from an anticorrosion layer-coated steel pipe, comprising a tool body and an operating body for rotating the tool body. 9. The anticorrosion layer of the anticorrosion layer-coated steel pipe according to claim 8, wherein a cap having a fitting portion for fitting the operating body is detachably attached to at least one end of the tool body. Peeling tool. 10. The tool for peeling an anticorrosion layer from an anticorrosion layer-coated steel pipe according to claim 8, wherein the operating body is a wrench with a ratchet.