JPH11190472A - Titanium spiral pipe titanium sheet for spiral pipe, and manufacture those - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a titanium spiral pipe formed so that a titanium sheet is molded in a spiral shape and the edges of the titanium sheet are joined together, and to provide a titanium sheet used in a spiral pipe, and manufacture those. SOLUTION: In this titanium spital pipe formed so that through spiral molding of a titanium sheet, the edges of the titanium sheet are joined together, an oxygen and/or nitrogen enriched layer is formed on at least one surface. Further, due to the above, a color or coloring is applied to manufacture a spiral pipe made of titanium. By applying high temperature heating on the titanium sheet in oxygen or/and nitrogen-contained atmosphere, the surface of a titanium sheet is brought into a colored or a coloring state due to the oxygen or/and nitrogen enriched layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a titanium spiral tube formed by spirally forming a titanium thin plate and joining edges of the titanium thin plate to each other, a titanium thin plate used for the spiral tube, and a method of manufacturing the same. It is.

[0002]

2. Description of the Related Art A method of manufacturing a metal pipe is characterized in that a metal sheet is wound around the outside or inside of a cylinder serving as a guide and spirally formed, and edges of the metal sheet are joined to each other to form a spiral tube. Are known. As a method for joining the edges of the thin metal plates, a welding method, a mechanical joining method using screws or ribs, a method using an adhesive, a goby folding fitting method, or the like can be used. When the joint is formed by goby folding fitting, the metal tube has a shape shown in FIG. As shown in FIG. 1 (b), by applying a corrugate to the surface of the thin plate,
The rigidity of the spiral tube can be increased. In the goby-fold fitting, both ends of the metal strip are processed into goby parts before spiral forming, and as shown in FIG. 1 (c), the ends of the adjacent thin plate after spiral forming are placed in a vertical relationship. Leverage and join to form a spiral tube. Typical materials for the spiral tube include copper, copper alloy, zinc-coated iron plate, stainless steel, and the like, and are used for applications such as automobile exhaust system piping, gas piping, water pipes, and exhaust gas flue.

When a spiral tube is used as a flue for exhaust gas, if a slight amount of hydrochloric acid, nitric acid, etc. contained in the exhaust gas is concentrated and condensed and accumulated inside the tube, the corrosion of the tube may occur after a long period of time. May progress. When buried in the ground, if the burial site is near the coast, it may be exposed to groundwater mixed with seawater, and high corrosion resistance is required to obtain long-term durability. However, it has not been possible to obtain sufficient corrosion resistance with conventionally used materials.

[0004]

SUMMARY OF THE INVENTION For applications requiring extremely good corrosion resistance, it has been desired to use a titanium thin plate having extremely excellent corrosion resistance as a material for a spiral tube. Conventionally, when a titanium thin plate is used as a material for a spiral tube, when the titanium thin plate is wound around the outside or inside of a cylinder serving as a guide and spirally formed, the titanium thin plate is not formed into a spiral shape well, and is adjacent after spiral forming. There is a problem that the spiral tube cannot be manufactured because the portions to be joined at the ends of the thin plate do not overlap well and cannot be joined, and a titanium spiral tube has not been put to practical use. In particular, when a corrugate was added to a titanium thin plate before spirally forming the thin plate, the degree of difficulty in spiral forming was high.

An object of the present invention is to solve the above problems and to provide a titanium spiral tube, a titanium thin plate for a spiral tube, and a method for producing the same.

[0006]

In manufacturing a spiral tube, a thin plate is formed into a spiral shape by rolling the thin plate and winding the thin plate around a cylinder serving as a guide with a predetermined angle of several degrees. A tube is formed. At that time, the spiral thin plate wound and formed around the cylinder serving as the guide is rotated around the cylinder serving as the guide, and is moved in parallel while sliding on the cylinder serving as the guide and is extruded to the end of the cylinder. . At the extruded stage, the edges of the spirally formed adjacent thin plates are in contact or overlap with each other so that the edges can be joined, so that the edges of the subsequent thin plates can be joined.

[0007] As a result of the study by the present inventors, in the production of a spiral tube using a titanium thin plate, the winding between the cylinder serving as a guide and the formed spiral titanium thin plate is caused by a large friction. It has been found that it is difficult to produce a titanium spiral tube because the thin plates cannot be moved parallel to each other, and thus cannot be accurately positioned at a position where the edges of the adjacent thin plates can be joined. In the case where a corrugated process for forming corrugated rows on a titanium thin plate is performed, the rigidity of the thin plate is increased, so that the forming becomes more difficult.

Furthermore, the present inventors have found that when an oxygen or / and nitrogen-enriched layer is formed on the surface of a titanium thin plate, the coefficient of friction on the surface of the titanium thin plate is reduced, and the spiral tube can be formed smoothly. Was found.

The present invention has been made on the basis of the above-mentioned examination results, and the gist thereof is as follows. First, in a titanium spiral tube formed by spirally forming a titanium sheet and joining edges of the titanium sheet to each other, the titanium sheet has an oxygen or / and nitrogen-enriched layer on at least one surface of the titanium sheet. And a titanium-made spiral tube characterized by being colored by the coloring. The edges of the titanium sheet can have a goby-folded fit at their joints, and it is possible to have at least one corrugate on the surface of the titanium sheet. The corrugate may be parallel to the longitudinal direction of the titanium sheet. The thickness of the oxygen- and / or nitrogen-enriched layer on the titanium surface is preferably 0.02 μm or more and 100 μm or less, more preferably 10 μm or less.
μm or less is preferred.

The second feature is that a titanium thin plate having an oxygen or / and nitrogen enriched layer on its surface is formed into a spiral, and the edges of the titanium thin plate are joined to each other to form a spiral tube. This is a method for manufacturing a tube.
In order to form an oxygen- and / or nitrogen-enriched layer on the surface of the titanium sheet, the titanium sheet can be heated at a high temperature in an atmosphere containing oxygen and / or nitrogen. The high-temperature heating is performed by rewinding the titanium sheet from a coiled state, rapidly heating the sheet in an atmosphere containing oxygen and / or nitrogen, cooling the sheet in a short time, and then winding the sheet again into a coil. Can be. After the spiral forming, the edges of the titanium thin plates can be joined together by goby folding fitting. Prior to the spiral forming, the titanium sheet may be subjected to roll forming to impart at least one corrugated shape to the surface of the titanium sheet. The corrugate may be parallel to the longitudinal direction of the titanium sheet.

A third aspect is a titanium thin plate for a spiral tube, characterized in that at least one surface is colored by coloring due to an oxygen- and / or nitrogen-enriched layer. The fourth
Is a method for producing a titanium thin plate for a spiral tube, wherein a titanium thin plate is heated at a high temperature in an oxygen or / and nitrogen-containing atmosphere to form an oxygen or / and nitrogen-enriched layer on the surface of the titanium thin plate. The high-temperature heating of the titanium sheet in the oxygen or / and nitrogen-containing atmosphere is performed by unwinding the titanium sheet from the coiled state, rapidly heating in the oxygen or / and nitrogen-containing atmosphere, and cooling in a short time. Later, it can be carried out by a method of winding again into a coil shape.

According to the present invention, an oxygen- and / or nitrogen-enriched layer is formed on the surface of a titanium thin plate, and the surface of the titanium thin plate is thereby colored by coloring, so that no oxygen- and / or nitrogen-enriched layer is formed on the surface. The coefficient of friction on the surface of the titanium thin plate decreased as compared with the case. As a result, good spiral forming becomes possible even when using a titanium thin plate,
After the spiral forming, the positioning accuracy of the adjacent thin plate ends is improved, and the joining can be performed to manufacture a spiral tube.

[0013]

DETAILED DESCRIPTION OF THE INVENTION Prior to manufacturing a spiral tube, in order to form an oxygen- and / or nitrogen-enriched layer on the surface of a titanium sheet, the titanium sheet is heated to a high temperature and placed in an atmosphere containing oxygen and / or nitrogen. Can be done by exposing.
It is most economical to use air at atmospheric pressure as the oxygen or / and nitrogen containing atmosphere. By holding the titanium thin plate at a temperature in the range of 300 ° C. to 1000 ° C. for several seconds to 15 minutes in such an oxygen or / and nitrogen-containing atmosphere, it is possible to form an oxygen or / and nitrogen rich layer on the surface of the titanium thin plate. As a result, the surface of the titanium thin plate can be colored. In order to form an oxygen- and / or nitrogen-enriched layer having the same thickness, the heat treatment time may be shorter as the heat treatment temperature is higher. As a preferable condition, the heat treatment can be performed at a temperature in a range of 600 ° C. to 800 ° C. for about 2 minutes. The color of the colored surface varies depending on the thickness of the oxygen- and / or nitrogen-enriched layer. As the thickness increases, the color and the thickness of the oxygen- and / or nitrogen-enriched layer (indicated in parentheses) are as follows. To change. That is, yellow (brownish yellow) (0.0
2 μm), purple (0.03 μm), blue (0.05 μm)
m), and thereafter, the same color is repeated as the thickness increases, and yellow (close to yellowish brown) (0.10 μm), purple (0.12 μm), green (0.15 μm), and gray (0.
20 μm or more). Any color within the above range is suitable for producing the titanium spiral tube of the present invention. It is considered that the structure of the oxygen-enriched layer is a structure centered on the titanium oxide film.

The thickness of the oxygen- and / or nitrogen-enriched layer is set to 0.0
The reason for setting the thickness between 2 μm and 100 μm is 0.02 μm or less.
If the thickness is less than μm, the effect of the present invention cannot be obtained because the coefficient of friction is large, and if it exceeds 100 μm, the oxygen- and / or nitrogen-enriched layer is easily peeled off. More preferably, the thickness of the oxygen and / or nitrogen enriched layer is no more than 10 μm. If the thickness exceeds 10 μm, the titanium thin plate itself is hardened. The thickness of the oxygen and / or nitrogen enriched layer can be determined by electron spectroscopy (Auger) or secondary ion mass spectroscopy (SIMS).
And the like.

[0015] Preferred conditions are 600 ° C to 800 ° C
When the heat treatment is performed in air at a temperature of 2 minutes, the colored coloring becomes gray, and the thickness of the oxygen- and / or nitrogen-enriched layer is 0.1 mm.
It becomes 5-2 μm.

[0016] The titanium sheet for manufacturing the spiral tube is as follows.
After the rolling is completed, it is usually wound around a coil. In order to form an oxygen- and / or nitrogen-enriched layer by heating the surface of the thin plate at a high temperature in an oxygen or / and nitrogen-containing atmosphere, equipment equivalent to a continuous annealing equipment for the thin sheet can be used. The titanium sheet is unwound from the coil, the titanium sheet is guided into a furnace for continuous annealing, heated, maintained at a temperature, and cooled, and the sheet exiting from the furnace is wound again into a coil. At this time, the atmosphere during heating and holding is an oxygen- and / or nitrogen-containing atmosphere.

When a method equivalent to the above-described continuous annealing is used as a method for forming an oxygen- and / or nitrogen-enriched layer on the surface, the titanium sheet is rapidly heated and cooled as a result. In the production of a spiral tube, the titanium sheet subjected to such rapid heating and rapid cooling can obtain the best production results. It is considered that the material of the titanium sheet obtained by rapid heating and rapid cooling has a favorable influence on the spiral formability.

As the method and apparatus for manufacturing a spiral tube used in the present invention, conventional methods and apparatuses conventionally used can be used as they are. As a cylinder serving as a guide, an iron cylinder is usually used. A titanium thin plate having a colored surface is wound around a cylinder serving as a guide and spirally formed, and the edges of the titanium thin plate are joined to form a spiral tube. When using the goby fold fitting as the joining method, goby bending portions are formed at both ends of the width of the titanium thin plate by roll forming before spiral forming, and after the spiral forming, the joined portions are bound by goby rolls to form a goby fold fit. Into a spiral tube. When a spiral tube with a corrugate is used, a thin plate is corrugated by roll forming before spiral forming, and then spiral forming is performed. Note that, for example, nitrogen may be used as an element other than oxygen that can form a stable thin film on the surface of the titanium thin plate and be colored.

[0019]

Examples: Fe: 0.038%, oxygen: 0.10%,
H: Using pure titanium of 0.001%, according to a normal manufacturing method of a titanium thin plate, a sheet thickness of 0.4 mm in a process of lumping, hot rolling, pickling, cold rolling, annealing, temper rolling, and re-annealing. Board width 145m
m of titanium sheet was manufactured. In the example of the present invention, the surface was colored in the re-annealing step.

Under the conditions of re-annealing, the example of the present invention used a continuous annealing furnace, and performed annealing in an atmosphere in the furnace using a mixed gas of Ar and the atmosphere or the atmosphere. In the comparative example, vacuum annealing and bell annealing were used. No. of the embodiment. 1 to 9 are examples of the present invention. N
o. In Nos. 1 to 5, the oxygen concentration was controlled by mixing the atmosphere with an Ar atmosphere. No. No. 1 was held at 700 ° C. for 2 minutes. 2
Is maintained at 730 ° C. for 2 minutes. No. 3 was kept at 750 ° C. for 2 minutes. No. 4 was held at 730 ° C. for 1 minute. 5 is 730
C. for 1.5 minutes. Heating rate is 1400 ° C / mi
n, and the cooling rate was 1200 ° C./min. N
o. In Nos. 6 and 7, continuous annealing was performed in an atmosphere having almost the same oxygen concentration as the atmosphere. No. The other conditions of No. 6 are No. 1 and No. 1
No. 7 is No. 7 The same conditions were used as in 2.

No. 1 of the present invention example. 7 and 8 are N
o. After performing the same continuous annealing as in Nos. 6 and 7, the following Nos. 1
The same vacuum annealing as in Example 0 was performed. As a result, the surface of the titanium thin plate crystal grains is changed to a coarse-grained structure from the annealed structure formed by continuous annealing while the surface remains colored.

In the embodiment No. 10 to 14 are comparative examples. No. 10 to 12 use vacuum annealing, and 20
After holding at 630 ° C. for 3, 5, and 7 hours at 630 ° C./hr, the furnace was cooled and the coil was taken out at room temperature. No. For Bells 13 and 14, bell atmosphere was used to replace the air atmosphere with an argon atmosphere, then kept at 650 ° C. for 3, 5 hours, cooled in a furnace, and taken out at room temperature. The thickness of each of the oxygen- and / or nitrogen-enriched layers in Comparative Examples was less than 0.02 μm.

The coefficient of friction of the annealed plate was determined by cutting a 400 mm plate having a width of 20 mm from the coil and subjecting each of the three to a friction test at an initial load of 250, 350, and 450 kg using a lubricating oil and an SKD11 tool. From the data of 445 kg, the coefficient of friction was calculated.

The spiral tube is manufactured by using a roll forming machine to make three rows of 9 mmφ semi-circular convex corrugates and 8 mm goby bends at both ends of the plate width, and wind them into a guide cylinder made of a 200 mmφ iron tube. Use a goby roll with a groove roll of 8mm width to tie the goby together and create an inner diameter of 200mmφ.
Was manufactured. The production result was defined as the pipe production yield at the time of spiral molding.

[0025]

[Table 1]

Table 1 shows the production results. In each of the examples of the present invention in which continuous annealing was performed in an atmosphere containing oxygen and nitrogen, an oxygen- and / or nitrogen-enriched layer was formed on the surface, and due to this, the layer was colored and the friction coefficient was low. The pipe production yield was the same as in the case of the continuous annealing of Example of the present invention. 1 to 7 were all 100%. Example No. 1 of the present invention in which vacuum annealing was performed after continuous annealing.
Samples 8 and 9 had slightly lower pipe production yields. On the other hand, in the comparative example, there was no colored coloring on the surface, the coefficient of friction was high, and the pipe production yield was a very low value.

[0027]

By forming an oxygen- and / or nitrogen-enriched layer on the surface of a titanium thin plate according to the present invention, it has become possible for the first time to manufacture a titanium spiral tube, which has been difficult in the past.

[Brief description of the drawings]

FIG. 1 is a plan view of a spiral tube of the present invention, wherein (a)
FIG. 3B is a detailed sectional view of the case where there is no corrugate, FIG. 3B is a case where there is a corrugate, and FIG.

[Explanation of symbols]

 1 Spiral tube (without corrugated) 2 Spiral tube (with corrugated) 3 Goby

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akihiko Kusano 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Corporation (72) Inventor Yasuo Takahashi 1-25-10, Hamamatsucho, Minato-ku, Tokyo Alloy Co., Ltd. (72) Inventor Hiroshi Hayakawa 1-6-1, Otemachi, Chiyoda-ku, Tokyo In the Research & Development Department, Taiheiyo Metal Co., Ltd. (72) Inventor Yoshihiro Takano 20-1 Shintomi, Futtsu City Nippon Steel Corporation Technology Development Division

Claims (16)

[Claims] 1. A titanium spiral tube formed by spirally forming a titanium thin plate and joining edges of the titanium thin plate to each other, wherein at least one surface of the titanium thin plate has an oxygen or / and nitrogen-enriched layer. A spiral tube made of titanium. 2. The titanium spiral tube according to claim 1, wherein the titanium thin plate is colored by coloring due to the oxygen or / and nitrogen-enriched layer on the surface. 3. The titanium spiral tube according to claim 1, wherein the edges of the titanium thin plates are formed by fitting the joints of the titanium thin plates with each other. 4. The titanium spiral tube according to claim 1, wherein at least one corrugate is provided on the surface of the titanium thin plate. 5. The titanium spiral tube according to claim 4, wherein the corrugate is parallel to the longitudinal direction of the titanium thin plate. 6. The titanium spiral tube according to claim 1, wherein the thickness of the oxygen- and / or nitrogen-enriched layer on the titanium surface is 0.02 μm or more and 100 μm or less. 7. The titanium spiral tube according to claim 1, wherein the thickness of the oxygen- and / or nitrogen-enriched layer on the surface of titanium is 0.02 μm or more and 10 μm or less. 8. A method for manufacturing a titanium spiral tube, comprising: forming a titanium thin plate having an oxygen or / and nitrogen-enriched layer on its surface by spiral forming; and joining the edges of the titanium thin plate to each other to form a spiral tube. Method. 9. A method for heating a titanium thin plate at a high temperature in an oxygen- and / or nitrogen-containing atmosphere so that oxygen or / and / or
The method for producing a titanium spiral tube according to claim 8, wherein a nitrogen-enriched layer is formed. 10. The high-temperature heating of a titanium sheet in an oxygen- and / or nitrogen-containing atmosphere is performed by unwinding the titanium sheet from a coiled state and rapidly heating the titanium sheet in an oxygen- and / or nitrogen-containing atmosphere. 10. The method according to claim 9, wherein the cooling is performed in a short time and then the coil is wound again.
3. The method for producing a titanium spiral tube according to item 1. 11. After adding roll forming to a titanium thin plate,
The method for manufacturing a titanium spiral tube according to any one of claims 8 to 10, wherein a spiral tube is formed by spirally forming the edges of the titanium thin plate so as to form a spiral tube by fitting the joints to each other. 12. The method according to claim 8, wherein prior to spirally forming the titanium sheet, roll forming is applied to the titanium sheet to give at least one corrugated shape to the surface of the titanium sheet. Of manufacturing a titanium spiral tube. 13. The method for manufacturing a titanium spiral tube according to claim 12, wherein the corrugate is parallel to a longitudinal direction of the titanium thin plate. 14. A titanium thin plate for a spiral tube, characterized in that at least one surface is colored by an oxygen- and / or nitrogen-enriched layer. 15. A method for producing a titanium sheet for a spiral tube, comprising heating a titanium sheet at a high temperature in an oxygen- and / or nitrogen-containing atmosphere to form an oxygen- and / or nitrogen-enriched layer on the surface of the titanium sheet. . 16. The high-temperature heating of a titanium thin plate in an oxygen- and / or nitrogen-containing atmosphere is performed by unwinding the titanium thin plate from a coiled state and rapidly heating the titanium thin plate in an oxygen- and / or nitrogen-containing atmosphere. 2. The method according to claim 1, wherein the cooling is performed in a short time and then the coil is wound again.
6. The method for producing a titanium thin plate for a spiral tube according to 5.