JPS6024324A - Heat treating device of metallic rod material having different wall thicknesses - Google Patents

Abstract

PURPOSE:To perform an efficient and uniform heat treatment of a steel pipe, etc. provided with thick-wall parts at both ends by moving two annular inductors for the thick-walled parts and normal part with respect to the metallic rod material having different wall thicknesses and heating and cooling the two parts. CONSTITUTION:An inductor 21 for a thick-walled part is placed on the outside circumference in the thick-walled part 1a at the end of a steel pipe 1, etc. and is heated to a prescribed temp. The inductor 21 is moved upward and cooling water is ejected from the nozzle of a jacket 31 to heat-treat uniformly the part 1a. The power supply to the inductor 21 is stopped and while an inductor 41 for a normal part is moved upward, the inductor is heated and the cooling water is ejected from the nozzle of a jacket 50 to heat-treat continuously the normal part. When the inductor 41 arrives at the prescribed position of the normal part 1c, the heat treatment by the inductor 21 standing by on the outside circumference of the upper thick-walled part 1b is started. Both ends of the steel pipe 1, etc. are kept supported by pipe end supporting members 2, 3 in this stage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for efficiently and uniformly heat treating metal strips having different wall thicknesses, particularly large ones with large thickness differences.

In recent years, metal structures used for offshore development and the like are large in size and are often destroyed by wind and waves due to the harsh natural environment in which they are installed.

Conventionally, from the viewpoint that it is necessary to increase the strength of the above structures in order to prevent such destruction, high tensile and thick steel materials have been used as structural materials. It is believed that accidents such as objects being submerged occur due to problems with the low-temperature toughness, weldability, etc. of the above-mentioned structural materials.

Therefore, in order to construct a structure with sufficient strength and excellent toughness, it is necessary to increase the toughness of the structural material by tempering the structure or shape of the structural material to some extent. It is also desirable to use threaded joints to avoid welding, which has obvious drawbacks. fi this point
i a 4') Looking at the case where a steel pipe is used for r,
Threaded silk at the end of the steel pipe; in order to form a thick wall for the hand and also to increase the toughness of the steel pipe with different wall thicknesses, the entire material must be subjected to a homogeneous heat treatment. .

However, since the above-mentioned steel pipes are used as structural materials, their overall wall thickness is large, and the pipe ends formed into threaded joints are formed to be, for example, three times as thick as other parts. The difference in thickness is large, and the overall shape ranges from about 50 cm in diameter to several meters, is at least 12 m long, and weighs at least 7 or 8 tons, so conventionally known general Depending on the heat treatment method and equipment, it is virtually impossible to efficiently and uniformly heat treat the above-mentioned steel pipes.

The inventors of the present invention have previously proposed a steel pipe that is large in size and has a large overall wall thickness, and in addition, the thick walled portion formed at the end is thickened with an even larger difference in wall thickness. As a method for efficiently and homogeneously heat-treating metal strips, metal strips having different wall thicknesses such that both ends are thicker than the steady portion are placed vertically or horizontally, and An annular inductor is placed on the starting end side of each portion of different wall thickness, and by moving the inductor in the longitudinal direction of the strip, the strip is continuously heated, and the heated portion is continuously heated. In the heat treatment, one of the thick sections of the strip is heated until it reaches a predetermined temperature while the entire thick section is surrounded by a thick inductor, and then the inductor is heated to a predetermined temperature. The inductor is supplied with electric power to compensate for the radiation convection loss of the heated part, and is moved in synchronization with this movement to the rear end side or to the boundary with the stationary part or to the vicinity thereof. Heat treatment is performed on the thick wall portion by continuously supplying cooling water to the heated portion, and following this treatment, an inductor for the steady section is placed on the starting end side of the steady section following the thick wall portion. The heating of the stationary part is started by supplying power to the inductor, and the inductor is moved toward the other end of the stationary part, and cooling water is continuously supplied to the part heated by the inductor in synchronization with the movement. ↓Thus, while continuously heat-treating the steady-state part, the time required for the inductor in the middle of the heat-treatment of the steady-state part to reach the end from there to the steady-state part and the thickness of the other thick-walled groups as a whole are reduced. Supplying power to the thick-walled inductor to start heating the thick-walled portion so that the time required to heat the thick-walled portion to a predetermined temperature by the thick-walled inductor matches the time required for heating the thick-walled portion to a predetermined temperature;
When the stationary section inductor reaches the terminal end of the stationary section or its vicinity, the power supply to the stationary section inductor is stopped and the radiation convection loss of the heated portion of the thick section inductor is reduced. The inductor is moved from the boundary side of the stationary section to the other end side while supplying enough power to compensate for the loss, and in synchronization with this movement, cooling water is continuously supplied to the part heated by the inductor. He has invented a heat treatment method.

The present invention has been made for the purpose of providing an apparatus that can effectively carry out the above heat treatment method, and is configured to support both ends of a metal strip having different wall thicknesses to be heat treated. and an annular or substantially annular inductor that substantially surrounds the thick part of the metal strip and has a notch partially or completely cut out in the thickness direction, and is movable in the longitudinal direction of the metal strip. An inductor for a thick wall portion that is integrally equipped with a cooling device that cools the heated portion immediately after heating the thick wall portion, and an inductor for the thick wall portion that surrounds a stationary portion of the metal strip and the inductor for the thick wall portion. An inductor for a stationary section, comprising an annular inductor that can be polymerized in or pass through the inductor, movable in the longitudinal direction of the metal strip, and integrally equipped with a cooling device similar to the inductor for thick internal parts. It is characterized by consisting of.

Next, embodiments of the present invention will be described with reference to the drawings.

(2) is a steel pipe to be heat treated as a structural material in which thick-walled portions 1a and 1b are formed in order to form threaded joints at both ends, and 1c is a stationary portion between the two thick-walled portions.

The steel pipe 1 has, for example, a nominal diameter of 500mm, a total length of 12m, a wall thickness of the steady portion 1c of 25 mm, and a wall thickness of the thick wall portions 1a and 1b at both ends of 75 mm. There are some steel pipes having a length of 700 mIn, but the metal strip to which the present invention can be applied is not limited to the above-mentioned steel pipes.

F is a machine frame, 2 is a tube end support member provided at the bottom of the machine frame F, 3 is a tube end support member also provided at the top, and the support member 2 supports the lower end of the tube 1; The upper ends of the tubes are centered and supported so that the tube 1 is vertical. Reference numeral 4 denotes a mounting member to which the support member 2 is rotatably mounted, and a gear 6 is fixed to the lower end of the mounting rod 5 of the support member 2. It meshes with the gear 8 provided at the tip of the shaft,
When the drive source 7 is driven, the support member 2 rotates together with the tube 1 while supporting the tube 1. 9 is a mounting rod for the support member 3; 10 is a mounting member that is attached to the upper part of the machine frame F and supports the mounting rod 9 in a rotatable and vertically movable manner; 11 is a worm disposed on the support member 10; with gears,
When this gear 11 and a worm 13 driven by a drive source 12 disposed on the upper part of the machine frame F are engaged and the drive source 12 is driven, the support member 3 moves up and down together with the mounting rod 9. It has become. Further, 14 is a spring interposed between the J member IO and the support member 3, which is used to cope with the expansion and contraction of the pipe 1 during heat treatment of the pipe 1.
1 to 14 constitute a device for supporting both ends of the tube I.

Reference numeral 21 denotes an inductor for thick-walled parts for heat-treating the thick-walled parts], a, and lb of the tube 1, and consists of inductors 21a and 21a in the shape of a semicircular enclosed inductor. Transformer 22
．． 22, and the other side is appropriately wide (separated by E, the whole has a substantially annular shape with a cutout 23, and the thick part 1a of the tube 1 or 1
This is so that b can be surrounded. 24 is the transformer 22, 2
2 is attached so that it can be moved back and forth, left and right, and the machine frame F
By fixing the tip of the wire 27 of the winch 26, which is connected to the guide rail 25 provided on one side and arranged on the upper part of the machine frame F, and driving the drive source 28, the winch is driven and the thickness is reduced. It can move up and down together with the meat part inductor 21. Also, 29, 29, 30, and 30 are the transformers 22, 22, the tube 1, and the inductor 21a.

A drive source for adjusting the clearance with 21a, 31
are cooling water jackets 1 to . that are integrally provided with the inductors 21a and 21a. Reference numeral 32 is a hose that supplies cooling water to the cooling water jacket 1 .

Reference numeral 41 denotes an annular stationary section inductor for heat-treating the normal section 1c of the pipe 1, and its lead section side is fixed to the transformer 42. Reference numeral 43 denotes a moving platform on which the transformer 42 is mounted so as to be movable back and forth, left and right, and similar to the moving platform 24, it is connected to a guide rail 44 provided on one side of the machine frame F and is arranged at the top of the machine frame F. By fixing the tip of the wire 46 of the winch 45 and driving the drive source 47, the winch 45 is driven and can move up and down together with the steady section inductor 41. Further, 48 and 49 are drive sources attached to the transformer 42 to adjust the clearance between the pipe 1 and the inductor 41;
50.51 is a cooling water jacket 1-152.53 provided integrally with the inductor 41 is a hose for supplying cooling water to the cooling water jacket 1-50, 51.

Incidentally, the relationship between the thick part inductor 21 and the steady part inductor 41 is such that the annular part of the steady part inductor 41 is similar to that of the thick part inductor 2.
1, and the lead portion side of the inductor 41 can pass through the defect 23 of the inductor 21. In other words, both inductors can move freely in opposite directions, passing each other. It looks like this.

As described above, an apparatus according to an example of the present invention is constructed, and a method for heat-treating the tube 1 using this apparatus will be described as follows.

FIG. 4 shows that the inductor 21 for thick-walled portions is positioned on the outer periphery of the thick-walled portion 1a at a portion indicated by the dotted line to complete the heat treatment of the thick-walled portion 1a, and then the inductor 21 is moved upward to remove the thick-walled portion 1a. This figure shows a state in which the stationary section 1c is heat-treated while the stationary section inductor 41 is driven while the stationary section 1b is on standby for heat treatment.The entire heat treatment is performed by the steps shown in FIGS. This is done by

First, as shown in FIG. With the child 21.41 in place, the driving source 7 is driven to rotate the tube 1, and power is supplied to the inductor 21 to start heating the thick part 1a, so that the part 1a reaches a predetermined temperature, e.g. 90
Heat in place until it reaches 0°C.

At this time, the steady-state inductor 41 is not operated.

In the figure, 11 is a heated portion.

When the thick portion 18 is heated to a predetermined temperature, the inductor 21
At the same time, the power supplied to the drive source 28 is reduced to a level that compensates for the heat radiation convection loss of the heated portion 1-1.
The inductor 21 begins to move upward by driving the inductor 21, and the cooling water C2 is spouted from the nozzle of the jacket 31 (see FIG. 6).

As a result of the above, the thick wall portion 1a is sequentially and continuously heat-treated from the bottom to the top, and the temperature of the thick wall portion 1a, which is later cooled by the heat-retaining heating action of the inductor 21, decreases in temperature. Therefore, uniform heat treatment of the thick wall part ]a can be achieved. Note that C in the figure is a portion that has been cooled after heating.

When the inductor 21 continues to move upward and the entire area of the part 1 heated by the inductor 21 is heat-treated, the inductor 21
At the same time, the inductor 41 for the stationary section set at the lower end of the stationary section 1c is stopped.
At the same time, power is supplied to the inductor 41, and the drive source 47 is driven to start moving the inductor 41 upward, and the process proceeds to heat treatment of the stationary part IC by the inductor 41 (see FIG. 7). Incidentally, the inductor 21 for the thick wall portion is further moved upward and placed in the cella 1 at the upper thick wall portion 1b.

The heat treatment of the stationary section 1c is carried out continuously by the heating movement of the inductor 41 and the jetting of the cooling water C3 from the nozzle of the cooling water jacket 50. When reaching , the thick part 1 of the second part
b The inductor 21 waiting on the outer periphery starts heating the part 1b (see FIG. 8).

That is, the predetermined position is determined by the time required for the inductor 41 for heating the stationary part 1c to reach the terminal end of the stationary part 1c from an appropriate position during movement, and the heating of the upper thick part 1b by the inductor 21 at a predetermined temperature, e.g. It is determined when the time required to heat the inductor 41 to ℃ coincides, and 5=Vl; (S: remaining moving distance of the inductor 41 for the stationary section, ■= moving speed of the inductor 41 mm/sec, t: It can be calculated from the equation: thick part lb & time required to heat to a predetermined temperature (5ee).

When the upper thick portion 1b starts to be heated by the stationary heating of the induction 7-21 and reaches a predetermined temperature, for example, 900°C, the inductor 41 for the steady portion lc is placed at the road end of the portion 1c. reach. Here, the stationary part 1c is the inductor 4
Since the inductor 41 is cooled by the cooling water c3 ejected from the nozzle of the cooling water jacket 1-50 disposed below the inductor 41, when the inductor 41 reaches a position where it cannot move any further, the area immediately below the inductor is cooled. become unable to do so. Therefore,
Water is passed through a cooling water jacket 51 provided above the inductor 41, and cooling water C3 is spouted from its nozzle to cool the upper end of the stationary portion 1c. (
(See Figure 9).

On the other hand, when the heat treatment for the entire area of the stationary part 10 is completed as described above, the inductor 21 that was heating the upper thick part 1b is driven with a heating output sufficient to compensate for the radiation convection loss of heat. At the same time as the drive source 28
starts moving the inductor 21 upward by driving the inductor 21, and
The cooling water C2 is jetted out from the nozzle of the cooling water jacket 1-31 to continuously heat-treat the thick portion 1b (see FIG. 10). The case where the upper and lower thick-walled parts 1a, ], b are the same size has been described above.
Thick wall portion 1a, 1. When the sizes of b are different, prepare J'X inductors suitable for heating the thick-walled parts 1a and Ib, and movably arrange them in the machine frame F. shall be taken as a thing.

In addition, FIG. 3 shows a thick wall inductor 21 formed into an annular shape split into two parts, and as shown in FIG. A cutout 23 is formed in the cutout 23 so that the lead portion of the stationary section inductor 41 can be loosely fitted into the cutout 23. This thick-walled inductor 21 is convenient for placing it individually in each n interior 1a, 'lb of the tube 1, and when it is placed in the thick-walled part 1b, the cutout 23 is the same as described above. On the contrary, it shall be formed on the lower side.

Further, in the above embodiments, an example was described in which the object to be heat-treated is a steel pipe, and the pipe is supported vertically while being heat-treated, but the present invention is not limited thereto.

The present invention is as described above, and includes a device that supports both ends of a metal strip having different wall thicknesses to be heat treated, and a device that substantially surrounds the thick portion of the metal strip and is uniform in the thickness direction. It is made up of an annular or substantially annular inductor having a notch in which part or all of the part is cut out, is movable in the longitudinal direction of the metal strip, and is integrated with a cooling device that cools the heated part immediately after heating the thick part. and an annular inductor that surrounds the stationary portion of the metal strip and can be polymerized into or pass through the thick wall inductor. Since the inductor for the steady section is movable in the longitudinal direction of the material and is integrally equipped with a cooling device similar to the inductor for the thick section, the method shown in FIGS. 5 to 10 can be used. It is suitable as a heat treatment apparatus for metal strips having different wall thicknesses, and is particularly suitable for large-sized devices with large overall wall thicknesses and thick sections formed at the ends with large thickness differences. It is extremely useful for efficiently and uniformly heat-treating steel pipes.

4. Additional related matters The original invention is a method for heat treatment of metal strips having different wall thicknesses, and the present invention is an apparatus for efficiently carrying out the heat treatment method.

[Brief explanation of drawings]

FIG. 1 is a partially sectional front view of an example of the device of the present invention;
FIG. 2 is a plan view of the main part, FIG. 3 is a perspective view showing the relationship between the separate inductor for the thick part and the inductor for the steady part, and FIG. Figures 5 to 10 are diagrams showing the positional relationship of the inductor during heat treatment of a steel pipe having the following characteristics. FIG. 3 is a diagram showing a heat treatment process using a brightening device. ■...Steel pipe, LA, LB...thick wall part, F...machine frame,
2, 3... Pipe end support member, 4... Mounting member, 5...
・Mounting rod, 6... Gear, 7... Drive source, 8... Gear, 9... Mounting rod, 10... Mounting member, 11... Worm gear, 12... Drive source, 13 ...warm, 1
4... Spring, 21... Inductor for thick part, 23...
Missing part, 24... Moving platform, 25... Guide rail, 26
...Winch, 27...Wire, 28,29.30.
... Drive source, 31... Cooling water jacket 1~. 4t...
Inductor for stationary section, 43. Moving platform, 71/I... Guide rail, 45 thread winch, 46... Wire, 47.48.
49... Drive source, 50. 51... Representative to cooling water jacket 1 Yoshikuni Koizumi Figure 2 30 C 21; 4th 3:S 3 Figure 90 Now Figure 10

Claims (1)

[Claims] 1. A device that supports both ends of a metal strip having different wall thicknesses to be heat treated, and an annular device that substantially surrounds the thick part of the metal strip and has a notch partially or completely cut out in the thickness direction. or an inductor for thick-walled parts, which is made of a substantially annular inductor, is movable in the longitudinal direction of the metal strip, and is integrally equipped with a cooling device that cools the heated part immediately after heating the thick-walled part; , consisting of an annular inductor that surrounds the stationary part of the metal strip and can be polymerized into or pass through the inductor for the thick part, movable in the longitudinal direction of the metal strip and having the thickness A heat treatment apparatus for metal strips having different wall thicknesses, comprising an inductor for a meat part and an inductor for a steady part integrally equipped with a similar cooling device.