WO2014142048A1 - Copper alloy seamless tube for cold and hot water supply - Google Patents

Copper alloy seamless tube for cold and hot water supply Download PDF

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Publication number
WO2014142048A1
WO2014142048A1 PCT/JP2014/056109 JP2014056109W WO2014142048A1 WO 2014142048 A1 WO2014142048 A1 WO 2014142048A1 JP 2014056109 W JP2014056109 W JP 2014056109W WO 2014142048 A1 WO2014142048 A1 WO 2014142048A1
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WO
WIPO (PCT)
Prior art keywords
water supply
copper alloy
hot water
seamless pipe
alloy seamless
Prior art date
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PCT/JP2014/056109
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French (fr)
Japanese (ja)
Inventor
哲也 安藤
Original Assignee
株式会社Uacj
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社Uacj filed Critical 株式会社Uacj
Priority to KR1020157023349A priority Critical patent/KR20150127600A/en
Priority to CN201480013639.1A priority patent/CN105074024B/en
Publication of WO2014142048A1 publication Critical patent/WO2014142048A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/002—Extruding materials of special alloys so far as the composition of the alloy requires or permits special extruding methods of sequences
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/02—Making uncoated products
    • B21C23/04—Making uncoated products by direct extrusion
    • B21C23/08—Making wire, bars, tubes
    • B21C23/085—Making tubes
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C9/00—Alloys based on copper
    • C22C9/02—Alloys based on copper with tin as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/08—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of copper or alloys based thereon

Definitions

  • the present invention is a copper alloy seamless pipe for water supply and hot water supply that circulates water in the pipe, and for example, a water flow path of a heat exchanger for a hot water supply pipe used for a circulating hot water supply system of a hotel, hospital, apartment, etc.
  • the present invention relates to a copper alloy seamless pipe used for the pipe.
  • a seamless pipe made of a copper alloy has often been adopted as a water flow path pipe of a heat exchanger for a piping water heater used in a circulating hot water supply system of a hotel, a hospital, an apartment and the like.
  • a seamless tube made of a solid solution strengthened type copper alloy to which Sn is added as in Patent Document 1 has an intermediate temperature brittleness and easily causes thermal fatigue and creep failure in a brittle temperature range.
  • the intermediate temperature brittleness is generated and the brittle crack is easily generated.
  • S and H content of a usual level is about 0.0005-0.0008 mass% of S, H is 0.0002-0.0010 mass% It is an extent.
  • an object of the present invention is to provide a copper alloy seamless tube for a heat transfer tube, which has high strength, little reduction in strength due to brazing, high creep deformation resistance, and a high effect of suppressing intermediate temperature brittleness. It is in.
  • the present inventors make the copper alloy contain Sn and Zr at a specific content, and further, add Zr in the copper alloy in an appropriate state. It is found that the presence of the copper alloy seamless pipe for water supply and hot water supply has high strength, little strength reduction due to brazing, high creep deformation resistance, and a high effect of suppressing intermediate temperature brittleness.
  • the present invention has been completed.
  • the present invention (1) is a copper alloy seamless pipe for water supply and hot water supply obtained by processing a copper alloy,
  • the copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu.
  • the electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (1): (1) 2-2- ⁇ 1 ⁇ 0.3 (% IACS) (Wherein, 1 1 refers to the electrical conductivity after solution treatment (% IACS), and ⁇ 2 refers to the electrical conductivity after aging treatment (% IACS))
  • % IACS electrical conductivity after aging treatment
  • the present invention (2) is a copper alloy seamless pipe for water supply and hot water supply obtained by processing a copper alloy,
  • the copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
  • the electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (2): (2) 4- 4- ⁇ 3 0.3 0.3 (% IACS) (Wherein ⁇ 3 is the conductivity (% IACS) after the heating-water-cooling test at 950 ° C. for 10 minutes, and ⁇ 4 is the conductivity (% IACS) after the heating-water-cooling test at 550 ° C. for 60 minutes Point)
  • % IACS the conductivity after the heating-water-cooling test at 550 ° C. for 60 minutes Point
  • a copper alloy seamless tube for a heat transfer tube which has high strength, little reduction in strength due to brazing, high creep deformation resistance, and a high effect of suppressing intermediate temperature brittleness.
  • the copper alloy seamless pipe for water supply and hot water supply of the first embodiment of the present invention (hereinafter, also described as the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention) is a water supply and hot water supply obtained by processing a copper alloy.
  • Copper alloy seamless pipe for The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu.
  • the electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (1): (1) 2-2- ⁇ 1 ⁇ 0.3 (% IACS) (Wherein, 1 1 refers to the electrical conductivity after solution treatment (% IACS), and ⁇ 2 refers to the electrical conductivity after aging treatment (% IACS))
  • % IACS the electrical conductivity after solution treatment
  • % IACS the electrical conductivity after aging treatment
  • the copper alloy seamless pipe for water supply and hot water supply of the second embodiment of the present invention (hereinafter, also described as the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention) is a water supply and hot water supply obtained by processing a copper alloy.
  • Copper alloy seamless pipe for The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
  • the electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (2): (2) 4- 4- ⁇ 3 0.3 0.3 (% IACS) (Wherein ⁇ 3 is the conductivity (% IACS) after the heating-water-cooling test at 950 ° C. for 10 minutes, and ⁇ 4 is the conductivity (% IACS) after the heating-water-cooling test at 550 ° C. for 60 minutes Point)
  • the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention and the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention are the electrical conductivity of the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention. While the formula (1) is satisfied, the same applies except that the electrical conductivity of the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention satisfies the formula (2).
  • the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention and the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention are, for example, piping water heaters used for circulating hot water supply systems in hotels, hospitals, apartments, etc.
  • a seamless pipe used as a water flow path pipe for water supply and hot water supply for circulating water in the pipe like a water flow path pipe of a heat exchanger for heat exchange, made of a copper alloy made of copper alloy, that is, a water supply and hot water supply pipe Is a copper alloy seamless pipe for
  • the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply according to the present invention contains Sn, Zr and P as essential elements, It is a copper alloy consisting of unavoidable impurities.
  • Sn has the effect of improving the strength of the copper alloy by solid solution hardening Has an effect of improving ductility.
  • these elements can be alloyed at relatively low temperatures, which is advantageous in manufacturing.
  • Zr has an effect of improving the strength of the copper alloy by precipitation strengthening.
  • Zr does not excessively increase the brazing temperature, Zr precipitates remain, and by suppressing coarsening of crystal grains, there is an effect of reducing strength reduction.
  • the content of Sn in the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is 0.45 to 0.90 mass% It is. If the content of Sn in the copper alloy is less than 0.45% by mass, the strength of the copper alloy is insufficient even if the solid solution strengthening by Sn and the precipitation strengthening by Zr are combined, and 0.90% by mass The work hardening becomes remarkable, the processability, in particular, the cold drawing processability deteriorates, and furthermore, the intermediate temperature brittleness tends to be caused.
  • the content of Zr in the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is 0.01 to 0.08 mass% It is. If the content of Zr in the copper alloy is less than 0.01% by mass, the effect of suppressing the coarsening of crystal grains is small, the strength reduction due to brazing becomes large, and solid solution strengthening by Sn and precipitation by Zr Even if the reinforcement is combined, the reinforcement of the copper alloy is insufficient. On the other hand, when the content of Zr in the copper alloy exceeds 0.08% by mass, excessive precipitation hardening occurs to cause the workability to be reduced. In particular, the cold rolling processability deteriorates. As a result, transfer of the spiral groove shape on the inner surface of the tube becomes insufficient, and it becomes difficult to obtain the heat transfer performance as obtained in C1220.
  • the content of P in the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is 0.004 to 0.04 mass% And preferably 0.015 to 0.030% by mass.
  • the copper alloy contains 0.004 mass% or more of P element, it is shown that deoxidation in the material is sufficient.
  • the content of P in the copper alloy is too large, the thermal conductivity of the copper alloy decreases, so the content of P in the copper alloy is 0.040 mass% or less.
  • ⁇ 2- ⁇ 1 is 0.3 or more, that is, the following formula (1): (1) 2-2- ⁇ 1 ⁇ 0.3 (% IACS) (Wherein, 1 1 refers to the electrical conductivity after solution treatment (% IACS), and ⁇ 2 refers to the electrical conductivity after aging treatment (% IACS))
  • the filling Preferably, 2-2- ⁇ 1 is 0.5 or more and 20 or less, that is, the following formula (1a): (1a) 0.5 ⁇ ⁇ 2- ⁇ 1 ⁇ 20 Meet.
  • rho 4-rho 3 is 0.3 or more, ie, following formula (2): (2) 4- 4- ⁇ 3 0.3 0.3 (% IACS) (Wherein ⁇ 3 is the conductivity (% IACS) after the heating-water-cooling test at 950 ° C. for 10 minutes, and ⁇ 4 is the conductivity (% IACS) after the heating-water-cooling test at 550 ° C. for 60 minutes Point)
  • the filling Preferably, 4-4- ⁇ 3 is 0.5 or more and 20 or less, that is, the following formula (2a): (2a) 0.5 ⁇ ⁇ 4- ⁇ 3 ⁇ 20 Meet.
  • the solution treatment refers to the treatment of sufficiently dissolving the Zr-based intermetallic compound crystallized in the process of cooling the ingot in the melting and casting steps
  • the aging treatment refers to the Zr-based metal. It refers to the process of precipitating an intermediate compound.
  • the copper alloy seamless pipe for water supply and hot water supply of the present invention is manufactured in the order of "melting and casting process-> hot extrusion process-> cold working process-> intermediate annealing process and rolling process-> aging process according to need" .
  • the heating in the hot extrusion process is a solution treatment for sufficiently dissolving the Zr-based intermetallic compound crystallized in the process of melting and cooling the ingot in the casting process.
  • the Zr crystallized in the ingot cooling process in the melting and casting steps is not sufficiently solid solution in solution treatment, the strength is obtained to match the Zr content. And the amount and distribution of fine precipitates precipitated in the aging treatment are not appropriate.
  • the Zr-based crystallized product which could not be solid-solved by solution treatment not only contributes not to the improvement of strength, but also in the subsequent cold working process, rolling process, bending process at the time of heat exchanger production. It will inhibit the processability.
  • solid solution Zr traps S by forming a compound with S in the solidification process or solution treatment at the time of casting, and also by trapping H that causes intergranular void formation during hot extrusion.
  • Zr which is in solid solution after the solution treatment not only contributes to the precipitation strengthening by the aging treatment which is a post process, but also contributes to the improvement of the creep resistance and the suppression of the intermediate temperature brittleness. Further, by setting the precipitation state of Zr in the aging treatment appropriately, the effect of suppressing the intermediate temperature brittleness is enhanced.
  • the present inventors made a solid solution state of Zr in the solution treatment due to the difference (2-2- ⁇ 1) between the electrical conductivity after the solution treatment and the electrical conductivity after the aging treatment. And, it has been found that the precipitation state of Zr in the aging treatment can be grasped, and creep resistance characteristics can be improved and the intermediate temperature brittleness can be suppressed by defining 2-2- ⁇ 1 in a specific range.
  • ⁇ 2- ⁇ 1 is 0.3 or more, that is, the following formula (1): (1) 2-2- ⁇ 1 ⁇ 0.3 (% IACS)
  • the filling Preferably, ⁇ 2- ⁇ 1 is 0.5 or more and 20 or less, that is, the following formula (1a): (1a) 0.5 ⁇ ⁇ 2- ⁇ 1 ⁇ 20 Meet.
  • the present inventors made a solution by the difference ( ⁇ 4- ⁇ 3) of the electrical conductivity after heating-water-cooling test at 950 ° C. for 10 minutes and the electrical conductivity after heating-water-cooling test at 550 ° C. for 60 minutes. It is possible to understand the solid solution state of Zr in the treatment and the precipitation state of Zr in the aging treatment, and by defining 4-4- ⁇ 3 in a specific range, the creep resistance property deformation is improved and the intermediate temperature brittleness is suppressed. I found that I could do it.
  • ⁇ 4- ⁇ 3 is 0.3 or more, that is, the following formula (2): (2) 4- 4- ⁇ 3 0.3 0.3 (% IACS)
  • the filling, Preferably, 4-4- ⁇ 3 is 0.5 or more and 20 or less, that is, the following formula (2a): (2a) 0.5 ⁇ ⁇ 4- ⁇ 3 ⁇ 20 Meet.
  • the heating-water-cooling test at 950 ° C. for 10 minutes is a test in which the copper alloy seamless tube to be tested is heated at 950 ° C. ⁇ 25 ° C. for 10 minutes and then water-cooled.
  • the test object is placed in an electric furnace set at 950 ⁇ 25 ° C. in a nitrogen gas atmosphere, and after the furnace temperature returns to 950 ° C., the test object is held at 950 ° C. ⁇ 25 ° C. for 10 minutes, then 950 It is carried out by immediately water cooling from ° C. Then, the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 950 ° C. for 10 minutes is measured to determine ⁇ 3.
  • % IACS electrical conductivity
  • the heating-water-cooling test at 550 ° C. for 60 minutes is carried out after heating and water-cooling the copper alloy seamless tube to be tested for 10 minutes at 950 ° C., and then 550 ° C. ⁇ 10 C. for 60 minutes and then water cooling.
  • the test object is heated at 950.degree. C .. +-. 25.degree. C. for 10 minutes and then 950.degree.
  • the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 550 ° C. ⁇ 10 ° C. for 60 minutes is measured to determine ⁇ 4.
  • the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply according to the present invention may further contain S atoms.
  • the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention further contains S, the inclusion of S in the copper alloy The amount is 0.0005 to 0.0010% by mass.
  • the copper alloy according to the copper alloy seamless pipe for water supply and hot water supply (1) of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention may further contain H.
  • the copper alloy according to the copper alloy seamless pipe for water supply and hot water supply (1) of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply according to the present invention further contains H
  • the copper alloy contains H in the copper alloy The amount is 0.0002 to 0.0020% by mass. If the content of S or H in the copper alloy exceeds the above range, S or H can not be sufficiently captured by the solid solution Zr, and the creep deformation resistance is improved, the intermediate temperature The effect of suppressing brittleness can not be obtained. On the other hand, when the content of S or the content of H in the copper alloy is less than the above range, the effects of improving the creep deformation resistance and suppressing the intermediate temperature brittleness can be obtained, but the cost tends to be increased.
  • the copper alloy seamless pipe for water supply and hot water supply of the present invention is manufactured by melting, casting and cooling ⁇ hot extrusion and cooling ⁇ cold working ⁇ intermediate annealing and rolling ⁇ aging in this order.
  • melt, cast and cool melting and casting.
  • melting and casting melting and casting are performed according to a conventional method to obtain a billet in which a predetermined element is blended at a predetermined content.
  • the content in the copper alloy seamless pipe of the present invention of the copper alloy of the present invention or the alloy of the contained element of the copper alloy seamless pipe of the copper alloy of the present invention and the copper alloy seamless pipe of the present invention The components are mixed so as to obtain a predetermined content, component adjustment is performed, and then a billet is cast using a high frequency melting furnace or the like. Then, after casting, the billet is cooled.
  • hot extrusion and cooling are performed.
  • a billet obtained by casting is heated at a predetermined temperature to be hot extruded.
  • Hot extrusion is performed by mandrel extrusion. That is, prior to heating, hot extrusion is performed with the mandrel inserted in a cold pre-perforated billet or a hot-perforated billet prior to extrusion. And after hot extrusion is performed, it cools rapidly and obtains a hot extrusion tube.
  • cold working is performed.
  • a hot extruded tube obtained by hot extrusion is cold worked by cold rolling, cold drawing, etc. to reduce the outer diameter and thickness of the tube, and a seamless tube obtain.
  • the seamless tube obtained by cold working is heated at 400 to 600 ° C. and then cooled. Aging treatment is performed. And the copper alloy seamless pipe (1) for water supply and hot water supply of this invention or the copper alloy seamless pipe (2) for water supply and hot water supply of this invention is obtained by performing an aging treatment.
  • an intermediate annealing is performed by heating the seamless tube obtained by cold working at 400 to 600 ° C., and then rolling.
  • a spiral grooved rolled plug is placed on the outer surface of a seamless tube and pressed from the outside of the tube by a plurality of rolling balls rotating at high speed to the inner surface of the tube. This is done by transferring the groove of the rolling plug.
  • the rolled seamless pipe is then subjected to an aging treatment.
  • the aging treatment is performed by heating and cooling the rolled seamless tube at 400 to 600.degree.
  • the copper alloy seamless pipe (1) for water supply and hot water supply of this invention or the copper alloy seamless pipe (2) for water supply and hot water supply of this invention is obtained by performing an aging treatment.
  • the electric conductivity can be expressed by the formula (1): ⁇ 2- ⁇ 1 ⁇ 0.3 (% IACS), preferably the formula (1a): 0.5
  • the electric conductivity can be expressed by the equation (2): 4- 4-3 3 0.3 0.3 (% IACS)
  • a method of setting equation (2a): 0.5 ⁇ 4-4-33 ⁇ 20 for example, a method of adjusting the cooling rate of the billet in melting and cooling after casting can be mentioned.
  • the present inventors differed in the existence state of Zr in the copper alloy due to the difference in the cooling rate of the billet in cooling after melting and casting, and the difference in the existence state of Zr after melting and casting was “ ⁇ 2- ⁇ 1”. And " ⁇ 4- ⁇ 3" values were found to affect.
  • the electrical conductivity preferably the formula (1a), depending on the billet diameter, the cooling method after casting, the cooling conditions after casting, the solution treatment conditions, the aging treatment conditions, etc.
  • the cooling rate suitable for adjusting to the appropriate cooling rate or equation (2), preferably equation (2a) is different
  • the cooling rate of the billet in the cooling after melting and casting is the diameter of the billet, the cooling It is appropriately selected according to the method, the cooling condition after casting, the solution treatment condition, the aging treatment condition and the like.
  • the electric conductivity of the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention can be expressed by the formula (2) by appropriately adjusting the diameter of the billet, the cooling condition after casting, the solution treatment condition, the aging treatment condition and the like. 1), preferably adjusted to satisfy the formula (1a), and the electric conductivity of the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is determined by the formula (2), preferably the formula (2a) Adjust to fill.
  • the copper alloy seamless pipe for water supply and hot water supply of the present invention is wound up in a coil shape as a heat transfer pipe for a heat exchanger, and is used for producing a heat exchanger (cross fin tube type heat exchanger).
  • the cross fin tube type heat exchanger is configured by integrally assembling an aluminum fin on the air side and a heat transfer pipe on the refrigerant side.
  • the cross fin tube type heat exchanger first, aluminum plate fins in which a plurality of predetermined assembly holes are formed are manufactured by pressing or the like, and then the obtained aluminum plate fins are laminated, and then the assembly holes are formed.
  • the copper alloy seamless pipe (1) for water supply and hot water supply according to the present invention and the copper alloy seamless pipe (2) for water supply and hot water supply according to the invention are inserted into the inside, and then the seamless pipe is formed. It is manufactured by brazing a U-bent pipe to an end portion of a seamless pipe opposite to a side which is fixed to an aluminum plate fin and is subjected to a hairpin bending process.
  • Example and Comparative Example ⁇ Copper alloy seamless pipe for water supply and hot water supply> (Melting, casting and cooling) A semi-continuous casting was used to cast a billet having an outer diameter of 254 mm containing the chemical components shown in Table 1 and then cooled. The amount of cooling water of the billet at this time was as follows. In Table 1, the balance is Cu and unavoidable impurities. Cooling condition A: Cooling water amount 1,000 L / min Cooling condition B: Cooling water amount 600 L / min (hot extrusion and cooling) The billet obtained as described above is heated by holding it at 950 ° C.
  • Example 1 A sample for measurement of electrical conductivity (sample 1) was sampled from the head and tail of the obtained hot-extruded tube. (Cold work) The hot-extruded plain tube obtained as described above was cold-rolled and cold-drawn to obtain a seamless plain tube with an outer diameter of 9.52 mm and a wall thickness of 0.8 mm.
  • the seamless tube obtained as described above was heated at 550 ° C. for 60 minutes in a non-oxidizing atmosphere in a batch furnace to obtain a copper alloy seamless tube for water supply and hot water supply. From the obtained copper alloy seamless pipe for water supply and hot water supply, sample 2 was sampled for electrical conductivity measurement. Also, Sample 3 and Sample 4 were sampled for the heating-water cooling test.
  • the heating-water-cooling test at 950 ° C. for 10 minutes is a test in which the copper alloy seamless tube to be tested is heated at 950 ° C. ⁇ 25 ° C. for 10 minutes and then water-cooled. Place the test object in an electric furnace set at ⁇ 25 ° C, and after the furnace temperature returns to 950 ° C, hold at 950 ° C ⁇ 25 ° C for 10 minutes and then immediately water cool from 950 ° C. It is done by Then, the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 950 ° C. for 10 minutes is measured to determine ⁇ 3.
  • the copper alloy seamless tube to be tested is heated and water-cooled for 10 minutes at 950 ° C, and then for 60 minutes at 550 ° C ⁇ 10 ° C.
  • the test target is first heated at 950 ° C ⁇ 25 ° C for 10 minutes in the same manner as the heating-water-cooling test at 950 ° C for 10 minutes and then immediately water cooled from 950 ° C.
  • the test object subjected to heating and water cooling at 950 ° C. for 10 minutes is placed in a salt bath furnace, held at 550 ° C. ⁇ 10 ° C. for 60 minutes, and then immediately water cooled.
  • the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 550 ° C. ⁇ 10 ° C. for 60 minutes is measured to determine ⁇ 4.
  • Heating-water cooling test 1 950 ° C ⁇ 25 ° C ⁇ 10 minutes First, charge sample 3 into an electric furnace set at 950 ⁇ 25 ° C in a nitrogen gas atmosphere, and the temperature in the furnace returns to 950 ° C. Then, it was held at 950 ⁇ 25 ° C. for 10 minutes and then immediately water-cooled from 950 ° C. to carry out heating-water cooling test 1.
  • Heating-water-cooling test 2 550 ° C. ⁇ 10 ° C. ⁇ 60 minutes
  • the sample 4 is heated and water-cooled at 950 ⁇ 25 ° C. for 10 minutes in the same manner as the heating-water-cooling test 1, and then heating-water-cooling
  • the same heating and water cooling sample 4 as in test 1 was placed in a salt bath furnace, held at 550 ° C. ⁇ 10 ° C. for 60 minutes, then immediately water cooled, and subjected to heating-water cooling test 2 .
  • thermo alloy fatigue test In a thermostat at 100 ° C., a thermal alloy fatigue test was performed by applying a repeated internal pressure of 0 to 15 MPa to the copper alloy seamless pipe 100,000 times. Those which did not form a crack during the test were regarded as pass.

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Abstract

A copper alloy seamless tube for cold and hot water supply obtained by processing a copper alloy, characterized in that: the copper alloy contains, by mass, 0.45 to 0.90% of Sn, 0.01 to 0.08% of Zr, and 0.004 to 0.04% of P, with the remainder being made up by Cu and unavoidable impurities; and the electrical conductivity of the copper alloy seamless tube for cold and hot water supply satisfies the following relationship (1): (1) ρ2-ρ1 ≥ 0.3 (%IACS)(where ρ1 represents the electrical conductivity (%IACS) after solution treatment and ρ2 represents the electrical conductivity (%IACS) after aging treatment). According to the present invention, it is possible to provide a copper alloy seamless tube for cold and hot water supply having high strength, little decrease in strength caused by brazing, high creep deformation resistance characteristics, and a high effect of suppressing intermediate temperature brittleness.

Description

給水給湯用銅合金継目無管Copper alloy seamless pipe for water supply and hot water supply
　本発明は、管内に水を流通させる給水給湯用の銅合金製の継目無管であり、例えば、ホテル、病院、マンション等の循環給湯システムなどに用いられる配管給湯機用熱交換器の水流路管に用いられる銅合金製の継目無管に関する。 The present invention is a copper alloy seamless pipe for water supply and hot water supply that circulates water in the pipe, and for example, a water flow path of a heat exchanger for a hot water supply pipe used for a circulating hot water supply system of a hotel, hospital, apartment, etc. The present invention relates to a copper alloy seamless pipe used for the pipe.
　従来より、ホテル、病院、マンション等の循環給湯システムなどに用いられる配管給湯機用熱交換器の水流路管には、銅合金製の継目無管が多く採用されてきた。 Conventionally, a seamless pipe made of a copper alloy has often been adopted as a water flow path pipe of a heat exchanger for a piping water heater used in a circulating hot water supply system of a hotel, a hospital, an apartment and the like.
　近年、これらの熱交換器では、重量の低減又はコストダウンの要求により、継目無管の薄肉化が必要となってきており、従来のりん脱酸銅管では強度が低いため、薄肉化は難しく、これに替わる銅合金製の継目無管の開発が求められている。 In recent years, with these heat exchangers, the need to reduce the weight or cost has made it necessary to reduce the thickness of the seamless pipe, and since the conventional phosphate-deoxidized copper pipe has low strength, the thickness reduction is difficult. There is a need to develop a copper alloy seamless tube to replace this.
　そこで、固溶強化型の銅合金としては、特許文献１には、Ｓｎを添加した銅合金が提案されている。また、固溶強化及び析出強化型銅合金としては、特許文献２及び特許文献３には、Ｓｎ及びＺｒを添加した銅合金が提案されている。 Then, the copper alloy which added Sn is proposed by patent document 1 as a solid solution strengthening type copper alloy. Moreover, as a solid solution strengthening and precipitation strengthening type copper alloy, the copper alloy which added Sn and Zr is proposed by patent document 2 and patent document 3. FIG.
特開２００３－２６８４６７号公報（特許請求の範囲）Unexamined-Japanese-Patent No. 2003-268467 (Claims) ＷＯ２００８／０４１７７７号公報（特許請求の範囲）WO 2008/041777 (Claims) 特開２０１１－９４１７４号公報（特許請求の範囲）JP, 2011-94174, A (claims)
　管内に水を流通させる給水給湯用銅合金継目無管には、熱膨張及び熱収縮の繰り返しに伴う熱疲労によって、疲労亀裂が発生する危険性がある。また、熱膨張に伴い継目無管に張力が発生し、使用温度によってはクリープ変形が発生する危険性がある。 In the copper alloy seamless pipe for water supply and water supply which circulates water in the pipe, there is a risk that fatigue cracks may occur due to thermal fatigue accompanying repetition of thermal expansion and thermal contraction. In addition, as a result of thermal expansion, tension is generated in the seamless pipe, and there is a risk that creep deformation may occur depending on the operating temperature.
　そのため、管内に水を流通させる給水給湯用銅合金継目無管には、「強度が高い」及び「ろう付けによる強度低下が少ない」に加え、耐熱疲労亀裂発生特性及び耐クリープ変形特性が備わっていることが求められる。 Therefore, in addition to "high strength" and "less reduction in strength due to brazing", copper alloy seamless pipes for water supply and hot water supply that distribute water in the pipe have heat fatigue crack initiation characteristics and creep deformation resistance characteristics. Need to be
　ところが、引用文献１のような、Ｓｎを添加した固溶強化型の銅合金製の継目無管には、中間温度脆性があり、脆性温度域において熱疲労、クリープ破壊を生じさせ易い。熱交換器の製造時、継目無管に張力がはたらいた状態でろう付け等の加熱をすることにより、中間温度脆性が発生し、脆化割れを生じ易い。 However, a seamless tube made of a solid solution strengthened type copper alloy to which Sn is added as in Patent Document 1 has an intermediate temperature brittleness and easily causes thermal fatigue and creep failure in a brittle temperature range. At the time of manufacturing the heat exchanger, by heating such as brazing while tension is applied to the seamless pipe, the intermediate temperature brittleness is generated and the brittle crack is easily generated.
　中間温度脆性を増進させる因子として、Ｓ及びＨがあり、Ｓ及びＨの含有量を極限まで下げることで、ある程度の中間温度脆性は抑制できるが、十分ではない。また、Ｓの含有量を極限まで下げるためには高純度の地金を使用する必要があり、コスト面で好ましくない。また、Ｈの含有量を極限まで下げるためには長時間の溶湯処理が必要、雰囲気コントロールを行った溶解鋳造が必要等、コスト面で好ましくない。 There are S and H as factors promoting intermediate temperature brittleness, and by lowering the S and H contents to the limit, some intermediate temperature brittleness can be suppressed but it is not sufficient. Moreover, in order to reduce the content of S to the limit, it is necessary to use a high purity metal, which is not preferable in terms of cost. Moreover, in order to reduce the content of H to the limit, it is necessary for the molten metal treatment for a long time, the melt casting with the atmosphere control is required, and the cost is not preferable.
　そのため、通常のレベル（極限まで下げることのないレベル）のＳ及びＨの含有量であっても、中間温度脆性を効果的に抑制させることが望ましい。なお、通常のレベル（極限まで下げることのないレベル）のＳ及びＨの含有量とは、Ｓが０．０００５～０．０００８質量％程度であり、Ｈが０．０００２～０．００１０質量％程度である。 Therefore, it is desirable to effectively suppress the intermediate temperature brittleness even if the content of S and H is a normal level (a level that does not decrease to the extreme). In addition, S and H content of a usual level (level which does not lower to the limit) is about 0.0005-0.0008 mass% of S, H is 0.0002-0.0010 mass% It is an extent.
　一方、特許文献２及び特許文献３のような、Ｓｎ及びＺｒを添加した固溶強化及び析出強化型の銅合金製の継目無管では、Ｚｒの添加により、強度が高いこと及びろう付けによる強度低下が少ないことに加え、中間温度脆性の発現をある程度抑制することができる。 On the other hand, in a solid tube made of solid solution strengthened and precipitation strengthened copper alloy with addition of Sn and Zr as in Patent Document 2 and Patent Document 3, the strength is high due to the addition of Zr and the strength by brazing. In addition to the decrease being small, the onset of intermediate temperature brittleness can be suppressed to some extent.
　しかしながら、更なる耐熱疲労亀裂発生特性の向上及び耐クリープ変形特性の向上が求められている。 However, there is a demand for further improvement in heat fatigue crack initiation characteristics and creep resistance characteristics.
　従って、本発明の目的は、強度が高く、ろう付けによる強度低下が少なく、耐クリープ変形特性が高く、且つ、中間温度脆性の抑制効果が高い伝熱管用の銅合金継目無管を提供することにある。 Therefore, an object of the present invention is to provide a copper alloy seamless tube for a heat transfer tube, which has high strength, little reduction in strength due to brazing, high creep deformation resistance, and a high effect of suppressing intermediate temperature brittleness. It is in.
　本発明者らは、上記従来技術における課題を解決すべく、鋭意研究を重ねた結果、銅合金にＳｎ及びＺｒを特定の含有量で含有させ、更に、Ｚｒを銅合金中に適切な状態で存在させることにより、強度が高く、ろう付けによる強度低下が少なく、耐クリープ変形特性が高く、且つ、中間温度脆性の抑制効果が高い給水給湯用の銅合金継目無管が得られることを見出し、本発明を完成させるに至った。 As a result of intensive studies to solve the problems in the above-mentioned prior art, the present inventors make the copper alloy contain Sn and Zr at a specific content, and further, add Zr in the copper alloy in an appropriate state. It is found that the presence of the copper alloy seamless pipe for water supply and hot water supply has high strength, little strength reduction due to brazing, high creep deformation resistance, and a high effect of suppressing intermediate temperature brittleness. The present invention has been completed.
　すなわち、本発明（１）は、銅合金を加工して得られる給水給湯用銅合金継目無管であり、
　該銅合金は、０．４５～０．９０質量％のＳｎと、０．０１～０．０８質量％のＺｒと、０．００４～０．０４質量％のＰと、を含有し、残部Ｃｕ及び不可避不純物からなり、
　該給水給湯用銅合金継目無管の電気伝導度が、下記式（１）：
　　　（１）ρ２－ρ１≧０．３（％ＩＡＣＳ）
（式中、ρ１は溶体化処理後の電気伝導度（％ＩＡＣＳ）を指し、ρ２は時効処理後の電気伝導度（％ＩＡＣＳ）を指す。）
を満たすこと、
を特徴とする給水給湯用銅合金継目無管を提供するものである。 That is, the present invention (1) is a copper alloy seamless pipe for water supply and hot water supply obtained by processing a copper alloy,
The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
The electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (1):
(1) 2-2-ρ1 ≧ 0.3 (% IACS)
(Wherein, 1 1 refers to the electrical conductivity after solution treatment (% IACS), and ρ 2 refers to the electrical conductivity after aging treatment (% IACS))
To meet
The copper alloy seamless pipe for water supply and hot water supply characterized by the above.
　また、本発明（２）は、銅合金を加工して得られる給水給湯用銅合金継目無管であり、
　該銅合金は、０．４５～０．９０質量％のＳｎと、０．０１～０．０８質量％のＺｒと、０．００４～０．０４質量％のＰと、を含有し、残部Ｃｕ及び不可避不純物からなり、
　該給水給湯用銅合金継目無管の電気伝導度が、下記式（２）：
　　　（２）ρ４－ρ３≧０．３（％ＩＡＣＳ）
（式中、ρ３は９５０℃で１０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指し、ρ４は５５０℃で６０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指す。）
を満たすこと、
を特徴とする給水給湯用銅合金継目無管を提供するものである。 The present invention (2) is a copper alloy seamless pipe for water supply and hot water supply obtained by processing a copper alloy,
The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
The electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (2):
(2) 4- 4-ρ 3 0.3 0.3 (% IACS)
(Wherein ρ3 is the conductivity (% IACS) after the heating-water-cooling test at 950 ° C. for 10 minutes, and ρ4 is the conductivity (% IACS) after the heating-water-cooling test at 550 ° C. for 60 minutes Point)
To meet
The copper alloy seamless pipe for water supply and hot water supply characterized by the above.
　本発明によれば、強度が高く、ろう付けによる強度低下が少なく、耐クリープ変形特性が高く、且つ、中間温度脆性の抑制効果が高い伝熱管用の銅合金継目無管を提供することができる。 According to the present invention, it is possible to provide a copper alloy seamless tube for a heat transfer tube, which has high strength, little reduction in strength due to brazing, high creep deformation resistance, and a high effect of suppressing intermediate temperature brittleness. .
　本発明の第一の形態の給水給湯用銅合金継目無管（以下、本発明の給水給湯用銅合金継目無管（１）とも記載する。）は、銅合金を加工して得られる給水給湯用銅合金継目無管であり、
　該銅合金は、０．４５～０．９０質量％のＳｎと、０．０１～０．０８質量％のＺｒと、０．００４～０．０４質量％のＰと、を含有し、残部Ｃｕ及び不可避不純物からなり、
　該給水給湯用銅合金継目無管の電気伝導度が、下記式（１）：
　　　（１）ρ２－ρ１≧０．３（％ＩＡＣＳ）
（式中、ρ１は溶体化処理後の電気伝導度（％ＩＡＣＳ）を指し、ρ２は時効処理後の電気伝導度（％ＩＡＣＳ）を指す。）
を満たすこと、
を特徴とする給水給湯用銅合金継目無管である。 The copper alloy seamless pipe for water supply and hot water supply of the first embodiment of the present invention (hereinafter, also described as the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention) is a water supply and hot water supply obtained by processing a copper alloy. Copper alloy seamless pipe for
The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
The electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (1):
(1) 2-2-ρ1 ≧ 0.3 (% IACS)
(Wherein, 1 1 refers to the electrical conductivity after solution treatment (% IACS), and ρ 2 refers to the electrical conductivity after aging treatment (% IACS))
To meet
A copper alloy seamless pipe for water supply and hot water supply characterized by
　本発明の第二の形態の給水給湯用銅合金継目無管（以下、本発明の給水給湯用銅合金継目無管（２）とも記載する。）は、銅合金を加工して得られる給水給湯用銅合金継目無管であり、
　該銅合金は、０．４５～０．９０質量％のＳｎと、０．０１～０．０８質量％のＺｒと、０．００４～０．０４質量％のＰと、を含有し、残部Ｃｕ及び不可避不純物からなり、
　該給水給湯用銅合金継目無管の電気伝導度が、下記式（２）：
　　　（２）ρ４－ρ３≧０．３（％ＩＡＣＳ）
（式中、ρ３は９５０℃で１０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指し、ρ４は５５０℃で６０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指す。）
を満たすこと、
を特徴とする給水給湯用銅合金継目無管である。 The copper alloy seamless pipe for water supply and hot water supply of the second embodiment of the present invention (hereinafter, also described as the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention) is a water supply and hot water supply obtained by processing a copper alloy. Copper alloy seamless pipe for
The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
The electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (2):
(2) 4- 4-ρ 3 0.3 0.3 (% IACS)
(Wherein ρ3 is the conductivity (% IACS) after the heating-water-cooling test at 950 ° C. for 10 minutes, and ρ4 is the conductivity (% IACS) after the heating-water-cooling test at 550 ° C. for 60 minutes Point)
To meet
A copper alloy seamless pipe for water supply and hot water supply characterized by
　本発明の給水給湯用銅合金継目無管（１）と本発明の給水給湯用銅合金継目無管（２）とは、本発明の給水給湯用銅合金継目無管（１）の電気伝導度が、式（１）を満たすのに対し、本発明の給水給湯用銅合金継目無管（２）の電気伝導度が、式（２）を満たす点が異なること以外は、同様である。 The copper alloy seamless pipe (1) for water supply and hot water supply of the present invention and the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention are the electrical conductivity of the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention. While the formula (1) is satisfied, the same applies except that the electrical conductivity of the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention satisfies the formula (2).
　本発明の給水給湯用銅合金継目無管（１）及び本発明の給水給湯用銅合金継目無管（２）は、例えば、ホテル、病院、マンション等の循環給湯システムなどに用いられる配管給湯機用熱交換器の水流路管のように、管内に水を流通させる給水給湯用の水流路管として用いられる継目無管であり、銅合金からなる銅合金製の継目無管、つまり、給水給湯用の銅合金製の継目無管である。 The copper alloy seamless pipe (1) for water supply and hot water supply of the present invention and the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention are, for example, piping water heaters used for circulating hot water supply systems in hotels, hospitals, apartments, etc. A seamless pipe used as a water flow path pipe for water supply and hot water supply for circulating water in the pipe like a water flow path pipe of a heat exchanger for heat exchange, made of a copper alloy made of copper alloy, that is, a water supply and hot water supply pipe Is a copper alloy seamless pipe for
　本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金は、Ｓｎ、Ｚｒ及びＰを必須元素として含有し、残部Ｃｕ及び不可避不純物からなる銅合金である。 The copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply according to the present invention contains Sn, Zr and P as essential elements, It is a copper alloy consisting of unavoidable impurities.
　本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）において、Ｓｎには、固溶強化により銅合金の強度を向上させる効果及び常温での延性を向上させる効果がある。また、これらの元素の場合、比較的低温で合金化できるので、製造上有利である。 In the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention, Sn has the effect of improving the strength of the copper alloy by solid solution hardening Has an effect of improving ductility. In addition, these elements can be alloyed at relatively low temperatures, which is advantageous in manufacturing.
　本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）において、Ｚｒには、析出強化により銅合金の強度を向上させる効果がある。また、Ｚｒには、ろう付け温度が過剰に高くならない前提では、Ｚｒ析出物が残存し、結晶粒の粗大化を抑制することにより、強度低下を小さくする効果がある。 In the copper alloy seamless pipe for water supply and hot water supply (1) of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention, Zr has an effect of improving the strength of the copper alloy by precipitation strengthening. In addition, on the premise that Zr does not excessively increase the brazing temperature, Zr precipitates remain, and by suppressing coarsening of crystal grains, there is an effect of reducing strength reduction.
　本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金中、Ｓｎの含有量は、０．４５～０．９０質量％である。銅合金中のＳｎの含有量が、０．４５質量％未満だと、Ｓｎによる固溶強化とＺｒによる析出強化を合わせても、銅合金の強化が不十分となり、また、０．９０質量％を超えると、加工硬化が著しくなり、加工性、特に、冷間での引き抜き加工性が悪くなり、更には、中間温度脆性を引き起こし易くなる。 The content of Sn in the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is 0.45 to 0.90 mass% It is. If the content of Sn in the copper alloy is less than 0.45% by mass, the strength of the copper alloy is insufficient even if the solid solution strengthening by Sn and the precipitation strengthening by Zr are combined, and 0.90% by mass The work hardening becomes remarkable, the processability, in particular, the cold drawing processability deteriorates, and furthermore, the intermediate temperature brittleness tends to be caused.
　本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金中、Ｚｒの含有量は、０．０１～０．０８質量％である。銅合金中のＺｒの含有量が、０．０１質量％未満だと、結晶粒粗大化を抑制する効果が小さく、ろう付けによる強度低下が大きくなり、また、Ｓｎによる固溶強化とＺｒによる析出強化を合わせても銅合金の強化が不十分となる。一方、銅合金中のＺｒの含有量が、０．０８質量％を超えると、過剰な析出硬化が起こり、加工性を低下させる原因となる。特に、冷間での転造加工性が悪くなる。その結果、管内面のらせん溝形状の転写が不十分となり、Ｃ１２２０で得られたような伝熱性能が得られ難くなる。 The content of Zr in the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is 0.01 to 0.08 mass% It is. If the content of Zr in the copper alloy is less than 0.01% by mass, the effect of suppressing the coarsening of crystal grains is small, the strength reduction due to brazing becomes large, and solid solution strengthening by Sn and precipitation by Zr Even if the reinforcement is combined, the reinforcement of the copper alloy is insufficient. On the other hand, when the content of Zr in the copper alloy exceeds 0.08% by mass, excessive precipitation hardening occurs to cause the workability to be reduced. In particular, the cold rolling processability deteriorates. As a result, transfer of the spiral groove shape on the inner surface of the tube becomes insufficient, and it becomes difficult to obtain the heat transfer performance as obtained in C1220.
　本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金中のＰの含有量は、０．００４～０．０４質量％であり、好ましくは０．０１５～０．０３０質量％である。銅合金が、Ｐ元素を０．００４質量％以上含有することにより、材料中の脱酸が十分であることが示される。そして、銅合金中のＰの含有量が、多すぎると、銅合金の熱伝導性が低くなるので、銅合金中のＰの含有量は、０．０４０質量％以下である。 The content of P in the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is 0.004 to 0.04 mass% And preferably 0.015 to 0.030% by mass. When the copper alloy contains 0.004 mass% or more of P element, it is shown that deoxidation in the material is sufficient. When the content of P in the copper alloy is too large, the thermal conductivity of the copper alloy decreases, so the content of P in the copper alloy is 0.040 mass% or less.
　本発明の給水給湯用銅合金継目無管（１）の電気伝導度については、ρ２－ρ１が０．３以上であること、すなわち、下記式（１）：
　　　（１）ρ２－ρ１≧０．３（％ＩＡＣＳ）
（式中、ρ１は溶体化処理後の電気伝導度（％ＩＡＣＳ）を指し、ρ２は時効処理後の電気伝導度（％ＩＡＣＳ）を指す。）
を満たし、
好ましくはρ２－ρ１は０．５以上２０以下であること、すなわち、下記式（１ａ）：
　　　（１ａ）０．５≦ρ２－ρ１≦２０
を満たす。また、本発明の給水給湯用銅合金継目無管（２）の電気伝導度については、ρ４－ρ３が０．３以上であること、すなわち、下記式（２）：
　　　（２）ρ４－ρ３≧０．３（％ＩＡＣＳ）
（式中、ρ３は９５０℃で１０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指し、ρ４は５５０℃で６０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指す。）
を満たし、
好ましくはρ４－ρ３は０．５以上２０以下であること、すなわち、下記式（２ａ）：
　　　（２ａ）０．５≦ρ４－ρ３≦２０
を満たす。 Regarding the electrical conductivity of the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention, ρ2-ρ1 is 0.3 or more, that is, the following formula (1):
(1) 2-2-ρ1 ≧ 0.3 (% IACS)
(Wherein, 1 1 refers to the electrical conductivity after solution treatment (% IACS), and ρ 2 refers to the electrical conductivity after aging treatment (% IACS))
The filling,
Preferably, 2-2-ρ1 is 0.5 or more and 20 or less, that is, the following formula (1a):
(1a) 0.5 ≦ ρ2-ρ1 ≦ 20
Meet. Moreover, about the electrical conductivity of the copper alloy seamless pipe (2) for water supply and hot water supply of this invention, rho 4-rho 3 is 0.3 or more, ie, following formula (2):
(2) 4- 4-ρ 3 0.3 0.3 (% IACS)
(Wherein ρ3 is the conductivity (% IACS) after the heating-water-cooling test at 950 ° C. for 10 minutes, and ρ4 is the conductivity (% IACS) after the heating-water-cooling test at 550 ° C. for 60 minutes Point)
The filling,
Preferably, 4-4-ρ3 is 0.5 or more and 20 or less, that is, the following formula (2a):
(2a) 0.5 ≦ ρ4-ρ3 ≦ 20
Meet.
　本発明において、溶体化処理とは、溶解及び鋳造工程での鋳塊の冷却過程で晶出したＺｒ系金属間化合物を十分に固溶させる処理を指し、また、時効処理とは、Ｚｒ系金属間化合物を析出させる処理を指す。本発明の給水給湯用銅合金継目無管は、「溶解及び鋳造工程→熱間押出工程→冷間加工工程→必要に応じて中間焼鈍処理及び転造工程→時効処理」の順に行い製造される。そして、このような製造工程では、熱間押出工程における加熱が、溶解及び鋳造工程での鋳塊の冷却過程で晶出したＺｒ系金属間化合物を十分に固溶させる溶体化処理となる。 In the present invention, the solution treatment refers to the treatment of sufficiently dissolving the Zr-based intermetallic compound crystallized in the process of cooling the ingot in the melting and casting steps, and the aging treatment refers to the Zr-based metal. It refers to the process of precipitating an intermediate compound. The copper alloy seamless pipe for water supply and hot water supply of the present invention is manufactured in the order of "melting and casting process-> hot extrusion process-> cold working process-> intermediate annealing process and rolling process-> aging process according to need" . And, in such a manufacturing process, the heating in the hot extrusion process is a solution treatment for sufficiently dissolving the Zr-based intermetallic compound crystallized in the process of melting and cooling the ingot in the casting process.
　銅合金製継目無管においては、溶解及び鋳造工程での鋳塊の冷却過程で晶出したＺｒが、溶体化処理で十分に固溶しないと、Ｚｒの含有量に見合った強度を得るための、時効処理で析出する微細な析出物の量及び分布が適正とはならない。また、溶体化処理で固溶しきれなかったＺｒ系晶出物は、強度向上に寄与しないばかりでなく、後の冷間加工工程、転造工程、熱交換器製作時の曲げ加工工程での加工性を阻害することになる。更に、固溶したＺｒは、鋳造時の凝固過程又は溶体化処理において、Ｓと化合物を生成することによってＳをトラップし、また、熱間押出時に粒界ボイドを形成させるＨをトラップすることにより、耐クリープ変形特性を向上させ、中間温度脆性を抑制する。このように、溶体化処理後に固溶しているＺｒは、後工程である時効処理による析出強化に寄与するばかりでなく、耐クリープ変形特性の向上、中間温度脆性の抑制に寄与する。また、時効処理でのＺｒの析出状態を適切なものとすることによって、中間温度脆性の抑制効果が高くなる。 In a copper alloy seamless tube, if the Zr crystallized in the ingot cooling process in the melting and casting steps is not sufficiently solid solution in solution treatment, the strength is obtained to match the Zr content. And the amount and distribution of fine precipitates precipitated in the aging treatment are not appropriate. In addition, the Zr-based crystallized product which could not be solid-solved by solution treatment not only contributes not to the improvement of strength, but also in the subsequent cold working process, rolling process, bending process at the time of heat exchanger production. It will inhibit the processability. Furthermore, solid solution Zr traps S by forming a compound with S in the solidification process or solution treatment at the time of casting, and also by trapping H that causes intergranular void formation during hot extrusion. Improves creep resistance and suppresses intermediate temperature brittleness. As described above, Zr which is in solid solution after the solution treatment not only contributes to the precipitation strengthening by the aging treatment which is a post process, but also contributes to the improvement of the creep resistance and the suppression of the intermediate temperature brittleness. Further, by setting the precipitation state of Zr in the aging treatment appropriately, the effect of suppressing the intermediate temperature brittleness is enhanced.
　ところが、溶体化処理でのＺｒの固溶状態及び時効処理でのＺｒの析出状態を、定量的にすることは難しい。そこで、本発明者らは、鋭意検討を重ねた結果、溶体化処理後の電気伝導度と時効処理後の電気伝導度の差（ρ２－ρ１）により、溶体化処理でのＺｒの固溶状態及び時効処理でのＺｒの析出状態の把握ができ、ρ２－ρ１を特定の範囲に規定することにより、耐クリープ変形特性を向上させ、中間温度脆性を抑制することができることを見出した。つまり、本発明の給水給湯用銅合金継目無管（１）の電気伝導度については、ρ２－ρ１が０．３以上であること、すなわち、下記式（１）：
　　　（１）ρ２－ρ１≧０．３（％ＩＡＣＳ）
を満たし、
好ましくはρ２－ρ１が０．５以上２０以下であること、すなわち、下記式（１ａ）：
　　　（１ａ）０．５≦ρ２－ρ１≦２０
を満たす。ρ２－ρ１が上記範囲内であることにより、耐クリープ変形特性を向上させ、中間温度脆性を抑制することができる。 However, it is difficult to quantitatively determine the solid solution state of Zr in solution treatment and the precipitation state of Zr in aging treatment. Therefore, as a result of intensive investigations, the present inventors made a solid solution state of Zr in the solution treatment due to the difference (2-2-ρ1) between the electrical conductivity after the solution treatment and the electrical conductivity after the aging treatment. And, it has been found that the precipitation state of Zr in the aging treatment can be grasped, and creep resistance characteristics can be improved and the intermediate temperature brittleness can be suppressed by defining 2-2- 耐 1 in a specific range. That is, with regard to the electrical conductivity of the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention, ρ2-ρ1 is 0.3 or more, that is, the following formula (1):
(1) 2-2-ρ1 ≧ 0.3 (% IACS)
The filling,
Preferably, ρ2-ρ1 is 0.5 or more and 20 or less, that is, the following formula (1a):
(1a) 0.5 ≦ ρ2-ρ1 ≦ 20
Meet. When ρ2-ρ1 is in the above range, the creep deformation resistance can be improved, and the intermediate temperature brittleness can be suppressed.
　また、本発明者らは、９５０℃で１０分間の加熱－水冷試験後の電気伝導度と５５０℃で６０分間の加熱－水冷試験後の電気伝導度の差（ρ４－ρ３）により、溶体化処理でのＺｒの固溶状態及び時効処理でのＺｒの析出状態の把握ができ、ρ４－ρ３を、特定の範囲に規定することにより、耐クリープ特性変形を向上させ、中間温度脆性を抑制することができることを見出した。つまり、本発明の給水給湯用銅合金継目無管（２）の電気伝導度については、ρ４－ρ３が０．３以上であること、すなわち、下記式（２）：
　　　（２）ρ４－ρ３≧０．３（％ＩＡＣＳ）
を満たし、
好ましくはρ４－ρ３は０．５以上２０以下であること、すなわち、下記式（２ａ）：
　　　（２ａ）０．５≦ρ４－ρ３≦２０
を満たす。ρ４－ρ３が上記範囲内であることにより、耐クリープ変形特性を向上させ、中間温度脆性を抑制することができる。 Furthermore, the present inventors made a solution by the difference (ρ4-ρ3) of the electrical conductivity after heating-water-cooling test at 950 ° C. for 10 minutes and the electrical conductivity after heating-water-cooling test at 550 ° C. for 60 minutes. It is possible to understand the solid solution state of Zr in the treatment and the precipitation state of Zr in the aging treatment, and by defining 4-4- を 3 in a specific range, the creep resistance property deformation is improved and the intermediate temperature brittleness is suppressed. I found that I could do it. That is, regarding the electrical conductivity of the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention, 、 4-が 3 is 0.3 or more, that is, the following formula (2):
(2) 4- 4-ρ 3 0.3 0.3 (% IACS)
The filling,
Preferably, 4-4-ρ3 is 0.5 or more and 20 or less, that is, the following formula (2a):
(2a) 0.5 ≦ ρ4-ρ3 ≦ 20
Meet. By setting 4- 4 to 3 3 within the above range, the creep deformation resistance can be improved, and the intermediate temperature brittleness can be suppressed.
　なお、本発明において、９５０℃で１０分間の加熱－水冷試験とは、試験対象となる銅合金継目無管を９５０℃±２５℃で１０分間の加熱をした後水冷するという試験であり、先ず、窒素ガス雰囲気、９５０±２５℃に設定された電気炉内に、試験対象を装入し、炉内温度が９５０℃に復帰した後、９５０℃±２５℃で１０分間保持し、次いで、９５０℃から直ちに水冷することにより行われる。そして、９５０℃で１０分間加熱－水冷試験後の試験対象の電気伝導度（％ＩＡＣＳ）を測定して、ρ３を求める。 In the present invention, the heating-water-cooling test at 950 ° C. for 10 minutes is a test in which the copper alloy seamless tube to be tested is heated at 950 ° C. ± 25 ° C. for 10 minutes and then water-cooled. The test object is placed in an electric furnace set at 950 ± 25 ° C. in a nitrogen gas atmosphere, and after the furnace temperature returns to 950 ° C., the test object is held at 950 ° C. ± 25 ° C. for 10 minutes, then 950 It is carried out by immediately water cooling from ° C. Then, the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 950 ° C. for 10 minutes is measured to determine ρ3.
　また、本発明において、５５０℃で６０分間の加熱－水冷試験とは、試験対象となる銅合金継目無管を、９５０℃で１０分間の加熱と水冷を行った後、次いで、５５０℃±１０℃で６０分間の加熱をした後水冷するという試験であり、先ず、試験対象を、９５０℃で１０分間の加熱－水冷試験と同様にして、９５０℃±２５℃で１０分間加熱した後９５０℃から直ちに水冷し、次いで、９５０℃で１０分間の加熱と水冷を行った試験対象を、塩浴炉内に装入し、５５０℃±１０℃で６０分間保持し、次いで、直ちに水冷することにより行われる。そして、５５０℃±１０℃で６０分間加熱－水冷試験後の試験対象の電気伝導度（％ＩＡＣＳ）を測定して、ρ４を求める。 In the present invention, the heating-water-cooling test at 550 ° C. for 60 minutes is carried out after heating and water-cooling the copper alloy seamless tube to be tested for 10 minutes at 950 ° C., and then 550 ° C. ± 10 C. for 60 minutes and then water cooling. First, the test object is heated at 950.degree. C .. +-. 25.degree. C. for 10 minutes and then 950.degree. Water-cooled immediately, then heated and water-cooled at 950 ° C for 10 minutes and loaded in a salt bath furnace, held at 550 ° C ± 10 ° C for 60 minutes, and then immediately water-cooled To be done. Then, the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 550 ° C. ± 10 ° C. for 60 minutes is measured to determine ρ4.
　本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金は、更に、Ｓ原子を含有してもよい。本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金が、更に、Ｓを含有する場合、銅合金中のＳの含有量は、０．０００５～０．００１０質量％である。また、本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金は、更に、Ｈを含有してもよい。本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）に係る銅合金が、更に、Ｈを含有する場合、銅合金中のＨの含有量は、０．０００２～０．００２０質量％である。銅合金中のＳの含有量又はＨの含有量が、上記範囲を超えると、固溶しているＺｒによりＳ又はＨを十分に補足することができず、耐クリープ変形特性の向上、中間温度脆性の抑制の効果が得られない。一方、銅合金中のＳの含有量又はＨの含有量が、上記範囲未満の場合、耐クリープ変形特性の向上、中間温度脆性の抑制の効果は得られるが、コストアップになり易い。 The copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply according to the present invention may further contain S atoms. When the copper alloy according to the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention further contains S, the inclusion of S in the copper alloy The amount is 0.0005 to 0.0010% by mass. Further, the copper alloy according to the copper alloy seamless pipe for water supply and hot water supply (1) of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention may further contain H. When the copper alloy according to the copper alloy seamless pipe for water supply and hot water supply (1) of the present invention or the copper alloy seamless pipe (2) for water supply and hot water supply according to the present invention further contains H, the copper alloy contains H in the copper alloy The amount is 0.0002 to 0.0020% by mass. If the content of S or H in the copper alloy exceeds the above range, S or H can not be sufficiently captured by the solid solution Zr, and the creep deformation resistance is improved, the intermediate temperature The effect of suppressing brittleness can not be obtained. On the other hand, when the content of S or the content of H in the copper alloy is less than the above range, the effects of improving the creep deformation resistance and suppressing the intermediate temperature brittleness can be obtained, but the cost tends to be increased.
　本発明の給水給湯用銅合金継目無管は、溶解、鋳造及び冷却→熱間押出及び冷却→冷間加工→必要に応じて中間焼鈍処理及び転造→時効処理の順に行い製造される。 The copper alloy seamless pipe for water supply and hot water supply of the present invention is manufactured by melting, casting and cooling → hot extrusion and cooling → cold working → intermediate annealing and rolling → aging in this order.
　先ず、溶解、鋳造及び冷却を行う。溶解及び鋳造では、常法に従って、溶解及び鋳造して、所定の元素が所定の含有量で配合されているビレットを得る。例えば、銅の地金及び本発明の給水給湯用銅合金継目無管の含有元素の地金又は該含有元素と銅の合金を、本発明の給水給湯用銅合金継目無管中の含有量が、所定の含有量となるように配合して、成分調整を行い、次いで、高周波溶解炉等を用いて、ビレットを鋳造する。次いで、鋳造後、ビレットを冷却する。 First, melt, cast and cool. In melting and casting, melting and casting are performed according to a conventional method to obtain a billet in which a predetermined element is blended at a predetermined content. For example, the content in the copper alloy seamless pipe of the present invention of the copper alloy of the present invention or the alloy of the contained element of the copper alloy seamless pipe of the copper alloy of the present invention and the copper alloy seamless pipe of the present invention The components are mixed so as to obtain a predetermined content, component adjustment is performed, and then a billet is cast using a high frequency melting furnace or the like. Then, after casting, the billet is cooled.
　次いで、熱間押出及び冷却を行う。熱間押出では、鋳造により得られたビレットを、所定の温度で加熱して、熱間押出する。熱間押出は、マンドレル押出によって行われる。すなわち、加熱前に、冷間で予め穿孔したビレット、あるいは、押出前に熱間で穿孔したビレットに、マンドレルを挿入した状態で、熱間押出を行う。そして、熱間押出を行った後、速やかに冷却して、熱間押出素管を得る。 Then, hot extrusion and cooling are performed. In hot extrusion, a billet obtained by casting is heated at a predetermined temperature to be hot extruded. Hot extrusion is performed by mandrel extrusion. That is, prior to heating, hot extrusion is performed with the mandrel inserted in a cold pre-perforated billet or a hot-perforated billet prior to extrusion. And after hot extrusion is performed, it cools rapidly and obtains a hot extrusion tube.
　次いで、冷間加工を行う。冷間加工では、熱間押出により得られた熱間押出素管を、冷間圧延や冷間引き抜き等の冷間加工し、管の外径及び肉厚を減じていき、継目無素管を得る。 Next, cold working is performed. In cold working, a hot extruded tube obtained by hot extrusion is cold worked by cold rolling, cold drawing, etc. to reduce the outer diameter and thickness of the tube, and a seamless tube obtain.
　内面溝が形成されていない内面平滑管（ベアー管）を得る場合は、冷間加工に次いで、冷間加工により得られた継目無素管を、４００～６００℃で加熱し、次いで、冷却する時効処理を行う。そして、時効処理を行うことにより、本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）を得る。 In the case of obtaining an inner smooth tube (bear tube) in which the inner groove is not formed, next to cold working, the seamless tube obtained by cold working is heated at 400 to 600 ° C. and then cooled. Aging treatment is performed. And the copper alloy seamless pipe (1) for water supply and hot water supply of this invention or the copper alloy seamless pipe (2) for water supply and hot water supply of this invention is obtained by performing an aging treatment.
　内面溝が形成されている内面溝付管を得る場合、冷間加工に次いで、冷間加工により得られた継目無素管を、４００～６００℃で加熱する中間焼鈍を行い、次いで、転造を行う。転造は、継目無素管内に、外面にらせん状の溝加工を施した転造プラグを配置して、高速回転する複数の転造ボールによって、管の外側から押圧して、管の内面に転造プラグの溝を転写することにより行われる。次いで、転造を施した継目無管を時効処理する。時効処理は、転造を施した継目無管を、４００～６００℃で加熱し、冷却することにより行なわれる。そして、時効処理を行うことにより、本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）を得る。 In the case of obtaining an internally grooved tube having an inner groove formed, following cold working, an intermediate annealing is performed by heating the seamless tube obtained by cold working at 400 to 600 ° C., and then rolling. I do. In rolling, a spiral grooved rolled plug is placed on the outer surface of a seamless tube and pressed from the outside of the tube by a plurality of rolling balls rotating at high speed to the inner surface of the tube. This is done by transferring the groove of the rolling plug. The rolled seamless pipe is then subjected to an aging treatment. The aging treatment is performed by heating and cooling the rolled seamless tube at 400 to 600.degree. And the copper alloy seamless pipe (1) for water supply and hot water supply of this invention or the copper alloy seamless pipe (2) for water supply and hot water supply of this invention is obtained by performing an aging treatment.
　そして、本発明の給水給湯用銅合金継目無管（１）において、電気伝導度を、式（１）：ρ２－ρ１≧０．３（％ＩＡＣＳ）、好ましくは式（１ａ）：０．５≦ρ２－ρ１≦２０とする方法、また、本発明の給水給湯用銅合金継目無管（２）において、電気伝導度を、式（２）：ρ４－ρ３≧０．３（％ＩＡＣＳ）、好ましくは式（２ａ）：０．５≦ρ４－ρ３≦２０とする方法としては、例えば、溶解及び鋳造後の冷却において、ビレットの冷却速度を調節する方法が挙げられる。本発明者らは、溶解及び鋳造後の冷却におけるビレットの冷却速度の違いにより、銅合金中のＺｒの存在状態が異なり、溶解及び鋳造後のＺｒの存在状態の違いが、「ρ２－ρ１」及び「ρ４－ρ３」の値に影響を与えることを見出した。なお、ビレットの径、鋳造後の冷却方式、鋳造後の冷却条件、溶体化処理条件、時効処理条件等により、電気伝導度を、式（１）、好ましくは式（１ａ）に調節するために適切な冷却速度、あるいは、式（２）、好ましくは式（２ａ）に調節するために適切な冷却速度は、異なるため、溶解及び鋳造後の冷却におけるビレットの冷却速度は、ビレットの径、冷却方式、鋳造後の冷却条件、溶体化処理条件、時効処理条件等により、適宜選択される。また、ビレットの径、鋳造後の冷却条件、溶体化処理条件、時効処理条件等を適宜調節することにより、本発明の給水給湯用銅合金継目無管（１）の電気伝導度が、式（１）、好ましくは式（１ａ）を満たすように調節し、また、本発明の給水給湯用銅合金継目無管（２）の電気伝導度が、式（２）、好ましくは式（２ａ）を満たすように調節する。 And, in the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention, the electric conductivity can be expressed by the formula (1): ρ2-ρ1 ≧ 0.3 (% IACS), preferably the formula (1a): 0.5 In the method for setting ≦ 2-1 1 ま た 20, and in the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention, the electric conductivity can be expressed by the equation (2): 4- 4-3 3 0.3 0.3 (% IACS) Preferably, as a method of setting equation (2a): 0.5 ≦ 4-4-33 ≦ 20, for example, a method of adjusting the cooling rate of the billet in melting and cooling after casting can be mentioned. The present inventors differed in the existence state of Zr in the copper alloy due to the difference in the cooling rate of the billet in cooling after melting and casting, and the difference in the existence state of Zr after melting and casting was “、 2-ρ1”. And "ρ4-ρ3" values were found to affect. In order to adjust the electrical conductivity to the formula (1), preferably the formula (1a), depending on the billet diameter, the cooling method after casting, the cooling conditions after casting, the solution treatment conditions, the aging treatment conditions, etc. Since the cooling rate suitable for adjusting to the appropriate cooling rate or equation (2), preferably equation (2a) is different, the cooling rate of the billet in the cooling after melting and casting is the diameter of the billet, the cooling It is appropriately selected according to the method, the cooling condition after casting, the solution treatment condition, the aging treatment condition and the like. In addition, the electric conductivity of the copper alloy seamless pipe (1) for water supply and hot water supply of the present invention can be expressed by the formula (2) by appropriately adjusting the diameter of the billet, the cooling condition after casting, the solution treatment condition, the aging treatment condition and the like. 1), preferably adjusted to satisfy the formula (1a), and the electric conductivity of the copper alloy seamless pipe (2) for water supply and hot water supply of the present invention is determined by the formula (2), preferably the formula (2a) Adjust to fill.
　本発明の給水給湯用銅合金継目無管は、熱交換器用の伝熱管としてコイル形状に巻き取られ、熱交換器（クロスフィンチューブ型熱交換器）の作製に供される。クロスフィンチューブ型熱交換器は、空気側のアルミニウムフィンと冷媒側の伝熱管が一体に組付けられて構成されているものである。 The copper alloy seamless pipe for water supply and hot water supply of the present invention is wound up in a coil shape as a heat transfer pipe for a heat exchanger, and is used for producing a heat exchanger (cross fin tube type heat exchanger). The cross fin tube type heat exchanger is configured by integrally assembling an aluminum fin on the air side and a heat transfer pipe on the refrigerant side.
　クロスフィンチューブ型熱交換器は、先ず、プレス加工等により、所定の組付け孔が複数形成されたアルミニウムプレートフィンを作製し、次いで、得られたアルミニウムプレートフィンを積層した後、組付け孔の内部に、定尺切断及びヘアピン曲げ加工した本発明の給水給湯用銅合金継目無管（１）又は本発明の給水給湯用銅合金継目無管（２）を挿通し、次いで、継目無管を、アルミニウムプレートフィンに拡管固着し、ヘアピン曲げ加工を施した側とは反対側の継目無管端部に、Ｕベンド管をロウ付けすることにより、作製される。 In the cross fin tube type heat exchanger, first, aluminum plate fins in which a plurality of predetermined assembly holes are formed are manufactured by pressing or the like, and then the obtained aluminum plate fins are laminated, and then the assembly holes are formed. Inside, the copper alloy seamless pipe (1) for water supply and hot water supply according to the present invention and the copper alloy seamless pipe (2) for water supply and hot water supply according to the invention are inserted into the inside, and then the seamless pipe is formed. It is manufactured by brazing a U-bent pipe to an end portion of a seamless pipe opposite to a side which is fixed to an aluminum plate fin and is subjected to a hairpin bending process.
　次に、実施例を挙げて本発明を更に具体的に説明するが、これは単に例示であって、本発明を制限するものではない。 EXAMPLES The present invention will next be described in more detail by way of examples, which are merely illustrative and do not limit the present invention.
（実施例及び比較例）
＜給水給湯用銅合金継目無管＞
（溶解、鋳造及び冷却）
　半連続鋳造により、表１に示す化学成分を含有する外径２５４ｍｍのビレットを鋳造し、次いで、冷却した。このときのビレットの冷却水の水量を、以下の通りとした。なお、表１中、残部はＣｕ及び不可避不純物である。
　冷却条件Ａ：冷却水量１，０００Ｌ／分
　冷却条件Ｂ：冷却水量６００Ｌ／分
（熱間押出及び冷却）
　上記のようにして得たビレットを、連続加熱炉内で、９５０℃（±２５℃）で１０分間以上保持することにより加熱し、次いで、押出温度９５０℃で、外径８１ｍｍ×肉厚８ｍｍの管を押出し、押出後ただちに水中へ投入して冷却して、熱間押出素管を得た。このとき、溶体化処理を兼ねて行った。
　得られた熱間押出素管の頭部及び尾部から、電気伝導度の測定用サンプル（サンプル１）をサンプリングした。
（冷間加工）
　上記のようにして得た熱間押出無素管を、冷間圧延及び冷間抽伸し、外径９．５２ｍｍ×肉厚０．８ｍｍの継目無素管を得た。
（時効処理）
　上記のようにして得た継目無素管を、バッチ炉内で、非酸化性雰囲気中、５５０℃で６０分間加熱し、給水給湯用銅合金継目無管を得た。
　得られた給水給湯用銅合金継目無管から、電気伝導度測定用に、サンプル２をサンプリングした。また、加熱－水冷試験用に、サンプル３及びサンプル４をサンプリングした。 (Example and Comparative Example)
<Copper alloy seamless pipe for water supply and hot water supply>
(Melting, casting and cooling)
A semi-continuous casting was used to cast a billet having an outer diameter of 254 mm containing the chemical components shown in Table 1 and then cooled. The amount of cooling water of the billet at this time was as follows. In Table 1, the balance is Cu and unavoidable impurities.
Cooling condition A: Cooling water amount 1,000 L / min Cooling condition B: Cooling water amount 600 L / min (hot extrusion and cooling)
The billet obtained as described above is heated by holding it at 950 ° C. (± 25 ° C.) for 10 minutes or more in a continuous heating furnace, and then an extrusion temperature of 950 ° C., outer diameter 81 mm × thickness 8 mm The tube was extruded, and immediately after the extrusion, it was poured into water and cooled to obtain a hot extruded tube. At this time, the solution treatment was also performed.
A sample for measurement of electrical conductivity (sample 1) was sampled from the head and tail of the obtained hot-extruded tube.
(Cold work)
The hot-extruded plain tube obtained as described above was cold-rolled and cold-drawn to obtain a seamless plain tube with an outer diameter of 9.52 mm and a wall thickness of 0.8 mm.
(Aging treatment)
The seamless tube obtained as described above was heated at 550 ° C. for 60 minutes in a non-oxidizing atmosphere in a batch furnace to obtain a copper alloy seamless tube for water supply and hot water supply.
From the obtained copper alloy seamless pipe for water supply and hot water supply, sample 2 was sampled for electrical conductivity measurement. Also, Sample 3 and Sample 4 were sampled for the heating-water cooling test.
＜加熱－水冷試験＞
　９５０℃で１０分間の加熱－水冷試験とは、試験対象となる銅合金継目無管を９５０℃±２５℃で１０分間の加熱をした後水冷するという試験であり、先ず、窒素ガス雰囲気、９５０±２５℃に設定された電気炉内に、試験対象を装入し、炉内温度が９５０℃に復帰した後、９５０℃±２５℃で１０分間保持し、次いで、９５０℃から直ちに水冷することにより行われる。そして、９５０℃で１０分間加熱－水冷試験後の試験対象の電気伝導度（％ＩＡＣＳ）を測定して、ρ３を求める。
　また、５５０℃で６０分間の加熱－水冷試験とは、試験対象となる銅合金継目無管を、９５０℃で１０分間の加熱と水冷を行った後、次いで、５５０℃±１０℃で６０分間の加熱をした後水冷するという試験であり、先ず、試験対象を、９５０℃で１０分間の加熱－水冷試験と同様にして、９５０℃±２５℃で１０分間加熱した後９５０℃から直ちに水冷し、次いで、９５０℃で１０分間の加熱と水冷を行った試験対象を、塩浴炉内に装入し、５５０℃±１０℃で６０分間保持し、次いで、直ちに水冷することにより行われる。そして、５５０℃±１０℃で６０分間加熱－水冷試験後の試験対象の電気伝導度（％ＩＡＣＳ）を測定して、ρ４を求める。 <Heating-water cooling test>
The heating-water-cooling test at 950 ° C. for 10 minutes is a test in which the copper alloy seamless tube to be tested is heated at 950 ° C. ± 25 ° C. for 10 minutes and then water-cooled. Place the test object in an electric furnace set at ± 25 ° C, and after the furnace temperature returns to 950 ° C, hold at 950 ° C ± 25 ° C for 10 minutes and then immediately water cool from 950 ° C. It is done by Then, the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 950 ° C. for 10 minutes is measured to determine ρ3.
In addition, with the heating-water-cooling test at 550 ° C for 60 minutes, the copper alloy seamless tube to be tested is heated and water-cooled for 10 minutes at 950 ° C, and then for 60 minutes at 550 ° C ± 10 ° C. The test target is first heated at 950 ° C ± 25 ° C for 10 minutes in the same manner as the heating-water-cooling test at 950 ° C for 10 minutes and then immediately water cooled from 950 ° C. Then, the test object subjected to heating and water cooling at 950 ° C. for 10 minutes is placed in a salt bath furnace, held at 550 ° C. ± 10 ° C. for 60 minutes, and then immediately water cooled. Then, the electrical conductivity (% IACS) of the test object after the heating-water-cooling test at 550 ° C. ± 10 ° C. for 60 minutes is measured to determine ρ4.
（加熱－水冷試験１）９５０℃±２５℃×１０分
　先ず、サンプル３を、窒素ガス雰囲気、９５０±２５℃に設定された電気炉内に装入し、炉内の温度が９５０℃に復帰した後、９５０±２５℃で１０分間保持し、次いで、９５０℃から直ちに水冷して、加熱－水冷試験１を行った。 (Heating-water cooling test 1) 950 ° C ± 25 ° C × 10 minutes First, charge sample 3 into an electric furnace set at 950 ± 25 ° C in a nitrogen gas atmosphere, and the temperature in the furnace returns to 950 ° C. Then, it was held at 950 ± 25 ° C. for 10 minutes and then immediately water-cooled from 950 ° C. to carry out heating-water cooling test 1.
（加熱－水冷試験２）５５０℃±１０℃×６０分
　先ず、サンプル４を、加熱－水冷試験１と同様にして、９５０±２５℃で１０分間の加熱と水冷を行い、次いで、加熱－水冷試験１と同様の加熱と水冷を行ったサンプル４を、塩浴炉内に装入し、５５０℃±１０℃で６０分間保持し、次いで、直ちに水冷して、加熱－水冷試験２を行った。 (Heating-water-cooling test 2) 550 ° C. ± 10 ° C. × 60 minutes First, the sample 4 is heated and water-cooled at 950 ± 25 ° C. for 10 minutes in the same manner as the heating-water-cooling test 1, and then heating-water-cooling The same heating and water cooling sample 4 as in test 1 was placed in a salt bath furnace, held at 550 ° C. ± 10 ° C. for 60 minutes, then immediately water cooled, and subjected to heating-water cooling test 2 .
＜評価＞
（機械的性質）
　トーチろう付けを、ろう材（ＪＩＳ　Ｚ３２６４　ＢＣｕＰ－２）及び酸素－プロパン混合ガスを用いて実施して、ろう付け後の耐圧強度測定用試料を作製した。このとき、ろう材が継ぎ手部に流れ込むまでろう付けを実施した。冷却は空冷とし、冷却後、水圧による破裂試験を行い、破壊強度から次式＊１を用い、引張り強さを推定し、ろう付け前後の機械的性質（引張強さと伸び）を評価した。
　ろう付け前の機械的性質を、引張試験により評価し、ＪＩＳ　Ｚ２２４１に準じ、引張強さと伸びを測定した。その結果を、表３に示す。
　　　＜式＊１＞ＫＨＫ式：破裂圧力＝２×引張強さ×肉厚／（外径－０．８×肉厚）
（電気伝導度）
　電気伝導度測定を、ＪＩＳ　Ｈ０５０５に準拠した方法、すなわち四端子法により電気抵抗を測定し、０．１５３２８で除した値を百分率で表した。
（中間温度脆性試験）
　銅合金継目無管を、３５０℃で、ひずみ速度１０－４の引張速度で引張試験した。伸び（δ）が３０％以上であったものを合格とした。
（熱疲労試験）
　１００℃の恒温槽内で、銅合金継目無管に、０から１５ＭＰａの繰り返し内圧を１０万回負荷し、熱疲労試験を行った。試験中に亀裂が生じなかったものを合格とした。 <Evaluation>
(mechanical nature)
The torch brazing was carried out using a brazing material (JIS Z3264 BCuP-2) and an oxygen-propane mixed gas to prepare a sample for measurement of compressive strength after brazing. At this time, brazing was performed until the brazing material flowed into the joint portion. Cooling was air cooling, and after cooling, a burst test was conducted by water pressure, and tensile strength was estimated from the breaking strength using the following equation * 1, and mechanical properties (tensile strength and elongation) before and after brazing were evaluated.
The mechanical properties before brazing were evaluated by a tensile test, and tensile strength and elongation were measured according to JIS Z2241. The results are shown in Table 3.
<Formula * 1> KHK type: Bursting pressure = 2 × tensile strength × thickness / (outside diameter-0.8 × thickness)
(Electrical conductivity)
The electrical resistance was measured by the method according to JIS H 0505, ie, the four-terminal method, and the value obtained by dividing by 0.15328 was expressed as a percentage.
(Intermediate temperature brittleness test)
The copper alloy seamless tube was tensile tested at 350 ° C. and at a strain rate of 10 −4 . A product whose elongation (δ) was 30% or more was regarded as a pass.
(Thermal fatigue test)
In a thermostat at 100 ° C., a thermal alloy fatigue test was performed by applying a repeated internal pressure of 0 to 15 MPa to the copper alloy seamless pipe 100,000 times. Those which did not form a crack during the test were regarded as pass.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003

Claims (3)

  1. 　銅合金を加工して得られる給水給湯用銅合金継目無管であり、
    該銅合金は、０．４５～０．９０質量％のＳｎと、０．０１～０．０８質量％のＺｒと、０．００４～０．０４質量％のＰと、を含有し、残部Ｃｕ及び不可避不純物からなり、
    　該給水給湯用銅合金継目無管の電気伝導度が、下記式（１）：
    　　　（１）ρ２－ρ１≧０．３（％ＩＡＣＳ）
    （式中、ρ１は溶体化処理後の電気伝導度（％ＩＡＣＳ）を指し、ρ２は時効処理後の電気伝導度（％ＩＡＣＳ）を指す。）
    を満たすこと、
    を特徴とする給水給湯用銅合金継目無管。     Copper alloy seamless pipe for water supply and hot water supply obtained by processing copper alloy
    The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
    The electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (1):
    (1) 2-2-ρ1 ≧ 0.3 (% IACS)
    (Wherein, 1 1 refers to the electrical conductivity after solution treatment (% IACS), and ρ 2 refers to the electrical conductivity after aging treatment (% IACS))
    To meet
    Copper alloy seamless pipe for water supply and hot water supply.
  2. 　銅合金を加工して得られる給水給湯用銅合金継目無管であり、
    　該銅合金は、０．４５～０．９０質量％のＳｎと、０．０１～０．０８質量％のＺｒと、０．００４～０．０４質量％のＰと、を含有し、残部Ｃｕ及び不可避不純物からなり、
    　該給水給湯用銅合金継目無管の電気伝導度が、下記式（２）：
    　　　（２）ρ４－ρ３≧０．３（％ＩＡＣＳ）
    （式中、ρ３は９５０℃で１０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指し、ρ４は５５０℃で６０分間の加熱－水冷試験後の電気伝導度（％ＩＡＣＳ）を指す。）
    を満たすこと、
    を特徴とする給水給湯用銅合金継目無管。     Copper alloy seamless pipe for water supply and hot water supply obtained by processing copper alloy
    The copper alloy contains 0.45 to 0.90% by mass of Sn, 0.01 to 0.08% by mass of Zr, and 0.004 to 0.04% by mass of P, with the balance being Cu. And inevitable impurities,
    The electrical conductivity of the copper alloy seamless pipe for water supply and hot water supply is represented by the following formula (2):
    (2) 4- 4-ρ 3 0.3 0.3 (% IACS)
    (Wherein ρ3 is the conductivity (% IACS) after the heating-water-cooling test at 950 ° C. for 10 minutes, and ρ4 is the conductivity (% IACS) after the heating-water-cooling test at 550 ° C. for 60 minutes Point)
    To meet
    Copper alloy seamless pipe for water supply and hot water supply.
  3. 　前記銅合金が、更に、０．０００５～０．００１０質量％のＳと、０．０００２～０．００２０質量％のＨと、を含有することを特徴とする請求項１又は２いずれか１項記載の給水給湯用銅合金継目無管。 The copper alloy further contains 0.0005 to 0.0010% by mass of S and 0.0002 to 0.0020% by mass of H. Copper alloy seamless pipe for water supply and hot water supply as described.
PCT/JP2014/056109 2013-03-11 2014-03-10 Copper alloy seamless tube for cold and hot water supply WO2014142048A1 (en)

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CN106017614A (en) * 2016-05-20 2016-10-12 河间市亚威电器制造有限公司 Oil level gauge and manufacturing method thereof
CN113488286A (en) * 2021-06-17 2021-10-08 重庆市南方阻燃电线电缆有限公司 Wire repairing method and wire repairing structure of mineral magnesium oxide insulated copper sheathed cable

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JP2008255381A (en) * 2007-03-30 2008-10-23 Kobelco & Materials Copper Tube Inc Heat resistant and high strength copper alloy tube for heat exchanger
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JP2011184775A (en) * 2010-03-10 2011-09-22 Kobe Steel Ltd High strength and high heat resistant copper alloy material
JP2011246802A (en) * 2010-04-28 2011-12-08 Sumitomo Electric Ind Ltd Cu-Ag ALLOY WIRE AND METHOD FOR PRODUCING Cu-Ag ALLOY WIRE

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JP2008255381A (en) * 2007-03-30 2008-10-23 Kobelco & Materials Copper Tube Inc Heat resistant and high strength copper alloy tube for heat exchanger
JP2010222692A (en) * 2009-03-25 2010-10-07 Sumitomo Light Metal Ind Ltd Copper alloy seamless pipe for supplying water and hot water
JP2011184775A (en) * 2010-03-10 2011-09-22 Kobe Steel Ltd High strength and high heat resistant copper alloy material
JP2011246802A (en) * 2010-04-28 2011-12-08 Sumitomo Electric Ind Ltd Cu-Ag ALLOY WIRE AND METHOD FOR PRODUCING Cu-Ag ALLOY WIRE

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106017614A (en) * 2016-05-20 2016-10-12 河间市亚威电器制造有限公司 Oil level gauge and manufacturing method thereof
CN106017614B (en) * 2016-05-20 2019-02-15 河间市亚威电器制造有限公司 A kind of oil level indicator and preparation method thereof
CN113488286A (en) * 2021-06-17 2021-10-08 重庆市南方阻燃电线电缆有限公司 Wire repairing method and wire repairing structure of mineral magnesium oxide insulated copper sheathed cable
CN113488286B (en) * 2021-06-17 2022-09-30 重庆市南方阻燃电线电缆有限公司 Wire repairing method and wire repairing structure of mineral magnesium oxide insulated copper sheathed cable

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MY173262A (en) 2020-01-09

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