AN ULTRA-THIN FLEXIBLE TUBE MADE OF AN ALLOY AND THE MANUFACTURE PROCESS THEREOF

Description

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a flexible tube made of alloy material, in particular, an ultra-thin flexible tube made of an alloy which can substitute common copper tube and is applicable for heat emission in air-conditioning and refrigeration. The present invention also relates to the manufacture process of said ultra-thin flexible tube.

Background

[0002] Generally, evaporators or radiators for current air-conditioning, refrigeration, fridge and heat emission are produced by copper tubes. Copper tubes have fine processability, high capability of heat dissipation and corrosion resistance. It is common knowledge that copper resource is gradually decreasing and its price is higher. The scarcity and high expense of copper resource becomes a bottle neck of material supply in the whole industry.

SUMMARY OF THE INVENTION

[0003] It is an objective of the present invention to provide an ultra-thin flexible tube made of an alloy, which can substitute copper tube and has high-efficient heat emission performance, high corrosion resistance and enough strength.

[0004] In one embodiment of the present invention, the present invention provides an ultra-thin flexible tube made of an alloy consisting of, in % by weight, Cr: 17 to 23, Ti: 0.1 to 0.35, Cu: 0.4 to 8.5, Mo: 0.2 to 2.4, Co: 0.01 to 0.06, Ni: 0.3 to 2.0, Nb: 0.2 to 1.0, V: 0.05 to 0.4, B: 0.001 to 0.020, Si: <1.0, Mn: <1.0, C: <0.020, N: <0.020, P: <0.035, S: <0.025, Mg: <0.005, O: <0.006, Al: <0.08, and the balance of Fe and inevitable impurities, with hardness HV 90 to 150, elongation rate 25% to 40% and chlorine ion resistance exceeding 100ppm under normal temperature.

[0005] The tube has a thickness of 0.04 mm to 0.2 mm, a strength about 1 time higher than that of copper material, a ductility similar to that of copper alloy material, and a thermal power higher than that of conventional copper alloy tubes. The tube could be used as a high-efficiency radiating tube in various air conditioners or refrigerating apparatus.

[0006] Another objective of the present invention is to provide a method of manufacturing said ultra-thin alloy flexible tube comprising steps of:

cold-rolling said alloy material into an alloy sheet with thickness from 0.04 mm to 0.20mm;

adjusting quality of said alloy sheet: quenching and tempering said alloy sheet in a bright furnace with temperature of 600°C to 780°C for 5 min to 20 min, to meet the toughness requirement in tubing process;

flattening said quenched alloy sheet in a flattening device until the flatness of said alloy sheet meet technical requirements of slivering and tubing processes;

slivering said alloy sheet into alloy strip coils with width corresponding to the outside diameter of said alloy flexible tube, and runout deviation of the width does not exceed 0.01 mm and the slivering depth does not exceed 0.002mm;

rolling preparation: loading the slivered alloy strip coil onto a coil cradle,

opening said alloy strip coil and shaping heads thereof for getting ready for starting rolling;

cleaning: put said heads into a cleaning device for thorough cleaning;

positioning: positioning the alloy strip into a predetermined operation rail;

rolling: putting the alloy strip into preformed molds, stepwise rolling the alloy strip into a tube blank with an outside diameter from 3.10 mm to 15.88 mm, wherein the diameter deviation of the tube blank does not exceed ±0.01 mm while its wall thickness exceeds 0.1 mm, and the diameter deviation of the tube blank does not exceed 0.003 mm while its wall thickness is smaller than 0.1 mm;

welding: continuously welding two longer edges of the tube blank along the length of the tube blank to form a tube, wherein the minimum thickness of its weld seam is not smaller than the wall thickness, the maximum thickness of its weld seam does not exceed 0.02 mm extending inward from the internal surface and 0.03 mm higher than the external surface of the tube blank, and the breadth of the weld seam is 4 to 8 times of the wall thickness;

thermal retardation: locating the welded tube in an environment with 1200°C to 180°C for thermal holding and cooling for 0.3 min to 1min to eliminate the influence of the welding;

defect detection and marking: detecting and marking defects in weld seams and the tube;

circularity rectifying and sizing: correcting the circularity of the tube and measuring its diameter and dimension to ensure the circularity and tolerance of diameter and dimension of the tube; and

coiling: loading the qualified tubes onto a coiling frame and winding them to form tube coils for future uncoiling, detection and/or usage.

[0007] As described, the composition of the alloy in above embodiments of the invention contains large dose of individual master element and small dose of various beneficial master elements meets welding performance requirement for making ultra-thin tubes. This one-piece configured ultra-thin alloy tube in accordance with the present invention possess industrial practical applicability with wall thickness of 0.04 mm to 0.2 mm, and its performance solves problems due to deficient performance of the copper tubes. Its chloride ion resistance is greater than 100ppm, which is about 50% higher than that of copper material. Therefore, the corrosion resistance is improved by 2 to 5 times and the strength is improved by about one time. Furthermore, its ductility is nearly similar to copper alloy material and its heat dissipation performance is high than that of existing tube made of copper alloy. It is a high-efficient tube, which can substitute current copper tube, has performance superior to current copper tube and can meet heat emission requirement of various air-conditioning and refrigerating devices.

DETAILED DESCRIPTION OF THE INVENTION

[0008] One or more specific embodiments of the present invention will be described below.

[0009] One preferred embodiment in accordance with the present invention is an ultra-thin flexible tube made of an alloy having an outside diameter of 5.3 mm and a wall thickness of 0.12 mm.

[0010] Said alloy consists of, in % by weight, Cr: 18, Ti: 0.15, Cu: 0.6, Mo: 1.0, Co: 0.02, Ni: 0.6, Nb: 0.5, V: 0.1, B: 0.005, Si: <0.10, Mn: <0.24, C: <0.004, N: <0.005, P: <0.006, S: <0.002, Mg: <0.001, O: <0.003, Al: <0.05, and the balance of Fe and inevitable impurities, with hardness HV 120, elongation 35% and chlorine ion resistance 200ppm under normal temperature.

[0011] Said preferred embodiment in accordance with the present invention also provides a manufacturing method of said alloy flexible tube. The method comprises steps of:

1. precisely cold-rolling said alloy material into an alloy sheet with thickness of 0.12 mm;

2. adjusting quality of said alloy sheet: quenching and tempering said alloy sheet in a bright furnace with temperature of 600°C to 780°C for 5 to 10min, to meet the toughness requirement in tubing process;

3. flattening said quenched alloy sheet in a flattening device until the flatness of said alloy sheet meet technical requirements of slivering and tubing processes;

4. precisely slivering said alloy sheet into alloy strip coils with width corresponding to the outside diameter of said alloy flexible tube, and runout deviation of the width does not exceed 0.01 mm and the slivering depth does not exceed 0.002mm, wherein the width is in accordance with the width required for rolling up said alloy strip to said alloy flexible tube with said diameter;

5. rolling preparation: loading the slivered alloy strip coil onto a coil cradle, opening said alloy strip coil and shaping heads thereof for getting ready for starting rolling;

6. cleaning: put said heads into a cleaning device for thorough cleaning;

7. positioning: positioning the alloy strip into a predetermined operation rail;

8. rolling: putting the alloy strip into preformed molds, stepwise rolling the alloy strip into a tube blank with an outside diameter of 5.3 mm, wherein the diameter deviation of the tube blank does not exceed 0.003 mm;

9. welding: continuously welding two longer edges of the tube blank along the length of the tube blank to form a tube, wherein the minimum thickness of its weld seam is not smaller than the wall thickness, the maximum thickness of its weld seam does not exceed 0.02 mm extending inward from the internal surface and 0.03 mm higher than the external surface of the tube blank, and the breadth of the weld seam is 4 to 8 times of the wall thickness;

10. thermal retardation: locating the welded tube in an environment with 1200°C to 180°C for thermal holding and cooling for 0.3 min to 1min to eliminate the influence of the welding;

11. defect detection and marking: detecting and marking defects by an automatic detecting device in weld seams and the main body of the tube;

12. circularity rectifying and sizing: correcting the circularity of the tube and measuring its diameter and dimension to ensure the circularity and tolerance of diameter and dimension of the tube; and

13. coiling: loading the qualified tubes onto a coiling frame and winding them to form tube coils for future uncoiling, detection and/or usage.

[0012] Another embodiment in accordance with the present invention provides an alloy flexible tube having an outside diameter of 9.52 mm and a wall thickness of 0.15 mm or 0.18mm.

[0013] Said alloy made into said flexible tube consists of, in % by weight, Cr: 19, Ti: 0.3, Cu: 8.0, Mo: 0.5, Co: 0.1, Ni: 1.0, Nb: 0.5, V: 0.1, B: 0.003, Si: <0.10, Mn: <0.2, C: <0.003, N: <0.003, P: <0.006, S: <0.002, Mg: <0.001, O: <0.003, Al: <0.05, and the balance of Fe and inevitable impurities, with hardness HV 110, elongation 40% and chlorine ion resistance 100ppm under normal temperature.

[0014] The manufacturing method and procedure of said alloy flexible tube are basically the same as described in the first preferred embodiment. Only the following steps are different:

1. precisely cold-rolling said alloy material into an alloy sheet with thickness of 0.15 mm or 0.18mm;

8. rolling: putting the alloy strip into preformed molds, stepwise rolling the alloy strip into a tube blank with an outside diameter of 9.52 mm, wherein the diameter deviation of the tube blank does not exceed ±0.01 mm.

[0015] The above is the detailed description of some preferred embodiments of the present invention, which can not be considered to restrict other embodiments in accordance with the present invention. The person having ordinary skill in the art may implement the invention in other forms without departing from the spirit thereof. Apparent changes and simple substitution of the invention will be deemed to be covered by the claims of the invention.

Claims

1. An ultra-thin flexible tube made of an alloy, which is characterized in that said alloy consists of, in % by weight, Cr: 17 to 23, Ti: 0.1 to 0.35, Cu: 0.4 to 8.5, Mo: 0.2 to 2.4, Co: 0.01 to 0.06, Ni: 0.3 to 2.0, Nb: 0.2 to 1.0, V: 0.05 to 0.4, B: 0.001 to 0.020, Si: <1.0, Mn: <1.0, C: <0.020, N: <0.020, P: <0.035, S: <0.025, Mg: <0.005, O: <0.006, Al: <0.08, and the balance of Fe and inevitable impurities, with hardness HV 90 to 150, elongation rate 25% to 40% and chlorine ion resistance exceeding 100ppm under normal temperature.

2. The ultra-thin flexible tube as claimed in claim 1, wherein said alloy consists of, in % by weight, Cr: 18, Ti: 0.15, Cu: 0.6, Mo: 1.0, Co: 0.02, Ni: 0.6, Nb: 0.5, V: 0.1, B: 0.005, Si: <0.10, Mn: <0.24, C: <0.004, N: <0.005, P: <0.006, S: <0.002, Mg: <0.001, O: <0.003, Al: <0.05, and the balance of Fe and inevitable impurities, with hardness HV 120, elongation 35% and chlorine ion resistance 200ppm under normal temperature.

3. The ultra-thin flexible tube as claimed in claim 1, wherein said alloy consists of, in % by weight, Cr: 19, Ti: 0.3, Cu: 8.0, Mo: 0.5, Co: 0.1, Ni: 1.0, Nb: 0.5, V: 0.1, B: 0.003, Si: <0.10, Mn: <0.2, C: <0.003, N: <0.003, P: <0.006, S: <0.002, Mg: <0.001, O: <0.003, Al: <0.05, and the balance of Fe and inevitable impurities, with hardness HV 110, elongation 40% and chlorine ion resistance 100ppm under normal temperature.

4. A method of manufacturing an ultra-thin alloy flexible tube, which is characterized in that the ultra-thin alloy flexible tube is made of an alloy described in claim 1, 2 or 3, and the method comprises steps of:

cold-rolling said alloy material into an alloy sheet with thickness from 0.04 mm to 0.20mm;

adjusting quality of said alloy sheet: quenching and tempering said alloy sheet in a bright furnace with temperature of 600°C to 780°C for 5 min to 20 min, to meet the toughness requirement in tubing process;

flattening said quenched alloy sheet in a flattening device until the flatness of said alloy sheet meet technical requirements of slivering and tubing processes;

slivering said alloy sheet into alloy strip coils with width corresponding to the outside diameter of said alloy flexible tube, and runout deviation of the width does not exceed 0.01 mm and the slivering depth does not exceed 0.002mm;

rolling preparation: loading the slivered alloy strip coil onto a coil cradle,

opening said alloy strip coil and shaping heads thereof for getting ready for starting rolling;

cleaning: put said heads into a cleaning device for thorough cleaning;

positioning: positioning the alloy strip into a predetermined operation rail;

rolling: putting the alloy strip into preformed molds, stepwise rolling the alloy strip into a tube blank with an outside diameter from 3.10 mm to 15.88 mm, wherein the diameter deviation of the tube blank does not exceed ±0.01 mm while its wall thickness exceeds 0.1 mm, and the diameter deviation of the tube blank does not exceed 0.003 mm while its wall thickness is smaller than 0.1 mm;

welding: continuously welding two longer edges of the tube blank along the length of the tube blank to form a tube, wherein the minimum thickness of its weld seam is not smaller than the wall thickness, the maximum thickness of its weld seam does not exceed 0.02 mm extending inward from the internal surface and 0.03 mm higher than the external surface of the tube blank, and

the breadth of the weld seam is 4 to 8 times of the wall thickness;

thermal retardation: locating the welded tube in an environment with 1200°C to 180°C for thermal holding and cooling for 0.3 min to 1min to eliminate the influence of the welding;

defect detection and marking: detecting and marking defects in weld seams and the tube;

circularity rectifying and sizing: correcting the circularity of the tube and

measuring its diameter and dimension to ensure the circularity and tolerance of diameter and dimension of the tube; and

coiling: loading the qualified tubes onto a coiling frame and winding them to form tube coils for future uncoiling, detection and/or usage.

5. The method as claimed in claim 4, wherein said alloy sheet has thickness of 0.12 mm, 0.15 mm or 0.18 mm.