JPS5954490A - Treatment by high frequency induction heating - Google Patents

Abstract

PURPOSE:To reduce considerably man-hour for operation in a treating method of the weld zone of an existing piping by high frequency induction heating by disposing a coil so as to heat the weld zone to be heated of the piping in such a way that said weld zone is covered. CONSTITUTION:A heating coil 2 is disposed to heat the longitudinal weld zone 1A to be heated of an existing piping 1 in such a way that said zone is covered in a treating method of the weld zone 1A in the longitudinal direction of the existing piping 1. The coil 2 is a non-split type coil consisting of an integral spiral shape. Then the coil shape can be reduced to about 1/7 of the size in the prior art and therefore there is no need for increasing the capacity of a power source installation with respect to the longitudinal seam of a large diameter piping. The need for the most laborious splitting of the coil is eliminated and the operation for the joining and connection of cooling pipes is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-frequency induction heating treatment method for existing plant piping, and provides a complete treatment method suitable for longitudinal welds of large-diameter piping.

Special for longitudinal seams of existing plant piping = I-No. 95
Conventionally, when carrying out a city frequency heat treatment not shown in No. 724, the method shown in FIG. 1 was used. The length of the first seam, t, is slightly wider than the length of the first seam, t. It was wrapped around.

Furthermore, in order to install the assembled coil Ia, it is divided into multiple parts and the two terminals i'' Yes (7)

1. For the circumferential joint from iIt to the longitudinal joint "f',"
, l is long, so the coil is large. p High-frequency generator equipment 1000 KV for long length
From A onwards.

2. Due to the increase in the size of the coil, if we take into account the limited space on site and the collection work at the 1'il site, the limit for confectionery making by a group of 4 people is 10 ri.
0 Ky/ II^1 It is necessary to divide the coil into multiple parts (1) Coil manufacturing will be complicated and difficult. 3. Since the coil will be divided into several rM pieces, the installation work to the target piping will be difficult due to the radioactivity level. For a high distribution 1f-t, and j2'5 touch a), the class <-1 [1 is an increase of 1. ．． ．． Several teams will be required to work on one location. Connect 4 water cooling pipe 2B to 11', 11 to terminal-2
Body, bolt tightening C", difficult work that resulted in tens of thousands of defects; q, iJ: Cooling water leakage, short circuit, which may lead to serious accidents, requiring careful work. It is.

4, -Y\times coil +i, +L is large / Kome, towing arrangement table 100 to 10, ν'' 1, Fit (1111 nozzle 4
・N-"?Su11 is becoming more and more common. Ko! L et al. if-;Q.

The purpose of the present invention is to eliminate the drawbacks of the prior art described above and to provide an optimal quotient frequency heating method for the χ part.

In the conventional round ↓(, the general method for hands, 1-tallow is the stock dividend 'f"j) +"1 as shown in Figures 1 and 2.
The method of winding the coil in the upper part is complicated due to the humanization of the coil and the increase in the number of divisions. '71♂,
Ground J (v work difficulties All 1 t: 1.
She is having sex with a lot of balls such as II balls. Due to the increase in the size of the cow T, there are 11 increases in power, 1. In the ground radioactive atmosphere ('F pear), it is a very difficult work to do Δ5.However, at present, C, it is necessary to divide the existing arrangement to understand the existing arrangement. Ta.

The present invention solves problems such as 1\],
Long sheets, Niatsumode■'), iI, Genseti +1°1
”Increase in capacity 11j〈■ Coil can also be made into a small QIJ 0) Field work! 1) Hl-The whole work is now divided (7, and 11. Ino's next trouble 4.1 [to -7=) The Kagamma Nomi☆Karihoshii 11, Suoto Mono de, 4 Riri, :JIl-Ki-Seirai no Hi 1' L Portrait ゛j1舅'' 2-roll winding type, ■, Ritoto J-
The welded part Jli) f, ;, (only is wound, Fig. 3 and :'(t41!;

51'・Delica type ((susej, I+, and C are also conventional high frequency 1□, 52.Delica type) Hold down 2, hand out C111 side, j, pass water.

: Temperature difference ΔT that causes plastic distortion noise of $1 in March
C: Boannon ratio l・], elastic modulus α for po r: thermal expansion anchoring σ A: by maintaining the entire yield point, stress corrosion cracking occurs in arrangement 1 A41
Note: It is recommended that the residual stress on the internal surface of the longitudinal welded portion of the paired pipe be less than 10 kg/w2 on the tensile side or on the compressive side, which is sufficient to prevent the stress.

Coils with the same shape as the piping are manufactured continuously using molds so as to match the longitudinal welding part of the target distribution W. In this case, the coil rlj should be 2.7 Vj ko2.

The above-mentioned non-divided flat-wound coil is installed on the target piping at the site by heat treatment, but it should be adjusted to ensure the maximum heating temperature, inward cooling water flow, and required temperature difference as described in +3i1. .

By the above method, υ, the residual stress on the inner surface of the pipe can be reduced by
Compared to the methods shown in Figures 1 and 2, it is possible to secure effects comparable to those shown in Figures 2 and 2. In addition, Figures 3 to 6 e'' are examples of application of the present invention), and Figure 5 is a reproduction of Figure 21'76.
・(Coil 'ff: taken in two parts/one section), 7th
It is also effective when applied to the plug welds shown in Figures and 8.

According to this method, the coil shape, jlL, i:+i: is 2
Taking BB piping as an example, it can be downsized to about 1/7, so it can also be used for long seams of large diameter pipes.
There is no need to increase the size of the coil, there is no need to divide the coil, which is the most troublesome part, there is no need to combine or connect the coil, and the number of tasks is reduced to one person. This has a great effect on reducing radiation exposure and improving the coil's flexibility.

[Brief explanation of drawings]

Figure 2 is a cross-sectional view showing the heat treatment method according to the conventional method; It is a cross-sectional view of the A-plane. Figure 5 shows the application of this invention. Direction 61 tangent (('- cross-sectional view when applying 7, A') X;;i
￥ 61M1lJ, its right side sectional view shows a). Figure 7 is a front view of an example in which the present invention is applied to a plug bath contact part.
j11 sectional view. . l... Heat treatment y1 ■ Target object, LA... Calculation,
b ] + IB object jib direction melting part, IB... heating tin ↓ 11) opium' snout circumferential direction lfi contact part, 2... for heating: 1 il, 2 people... heating coil 914i, 2B
...Cooling water pipe, l...Longitudinal direction welded part J, height, J7... Heating coil dimensions, 3... Plug welded part, R... Piping center radius, 1... Piping Thick. Agent Patent Attorney Akira Takahashi f7 l8,--I゛'i,□ ・Ichi no Iku I Kasumi 121 man A Klfθ'' 2A Figure 5, Figure 7, Figure 4

Claims (1)

[Claims] ■ In the high frequency U4 heat treatment force method for existing piping welds, the high frequency 11. 1;4
Conductive heat treatment force method. 2. Particularly 11'1 In the method described in claim 1, the coil 1 is formed into a non-divided coil having an integral spiral shape.
Features: High frequency induction heating treatment method.