CN101032730A

CN101032730A - Production method of bimetal pipe

Info

Publication number: CN101032730A
Application number: CN 200710048848
Authority: CN
Inventors: 唐谊光
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-12
Filing date: 2007-04-12
Publication date: 2007-09-12

Abstract

The present invention relates to production of metal pipe, and is especially production process of double-layer metal pipe. The production process includes the following steps: 1. necking down one end of the outer pipe while maintaining the other end unchanged; 2. derusting the outer surface of the inner pipe and the inner surface of the outer pipe; 3. threading the inner pipe into the outer pipe, aligning the necked end of the outer pipe with one end of the inner pipe, and welding one plug with a small hole; 4. welding one vacuum pumping set to the other end of the double pipe; 5. introducing pressure clean water into the inner pipe; and 6. vacuum pumping the sandwich between the outer and the inner pipes, heating and reducing. The process may be used in industrial production of double layer metal pipe.

Description

A kind of production process of double-layer

(1) technical field:

The present invention relates to the production method of metal tube, especially production process of double-layer.

(2) background technology:

The method of producing bimetal pipe at present roughly has interior pressure, diffusion method, suction pouring composite algorithm, plastic deformation liner method (internal pressurization, pipe plastic deformation in making), blast composite algorithm etc.With the bimetal pipe that these methods are produced, its compound mode is single, and pipe is stainless steel or copper in generally can only producing, and outer tube is the bimetal pipe of carbon steel or low-alloy steel.The tubing of other material, as aluminium or titanium and alloy thereof etc., the high temperature in the process can make described interior tubing matter be subjected to very big influence, makes the bond strength between inner and outer pipe low, so can not produce the bimetal pipe of any combination.

(3) summary of the invention:

The problem to be solved in the present invention is exactly to provide a kind of universal method that can produce the bimetal pipe of any combination at above deficiency, and this method can the industrialized mass production bimetal pipe.Its technical scheme may further comprise the steps:

1) with outer tube one end reducing, making the necking end internal diameter is interior external diameter of pipe _{+ 0.10} ^{+ 0.20}, the other end remains unchanged;

2) inner tube outer surface, outer pipe internal surface are carried out processing of rust removing completely;

3) interior pipe is penetrated in the outer tube, the outer tube necking end aligns with interior Guan Yiduan, and assembly welding one narrow meshed plug;

4) at other end assembly welding one vacuum pumping tool equipment of inner and outer pipe;

5) in interior pipe 2, be connected with the clean water of pressure;

6) vacuumize back heating, undergauge between inner and outer pipe;

7) cut off plug and vacuum pumping tool equipment, with bimetal pipe drawing on drawbench, shaping

Compared with prior art the present invention has following advantage:

1, can produce the bimetal pipe of combination arbitrarily to satisfy different manufacturing technique requirents by client's requirement with this method, as outer 304 stainless steel tubes/interior 20# pipe, outer 20#/interior 304 pipe stainless steels, outer 20#/interior titanium or titanium alloy tube, outer 20#/interior aluminum or aluminum alloy pipe, interior 20#/outer 16Mn pipe etc.; Tube thickness is between the 0.5-3.0 millimeter in it, and outer tube thickness changes between 2-50 millimeter (even bigger), can save the rare metallic material of a large amount of costlinesses, uses the equipment of this kind double-level-metal pipe manufacturer and pipeline cost to reduce significantly.

2, owing to vacuumize between interior pipe and outer tube, in hot procedure, the inner and outer pipe binding face can not produce oxide (or seldom oxide), and also because in the interior pipe water-cooled is arranged, tubing matter is unaffected in making, and also helps the bond strength that improves between inner and outer pipe;

3, since in whole hot procedure pipe be connected with the clean water of certain pressure, in be in control abundant cooling, and the rigidity of pipe in process in increasing, bimetal pipe with this method production, chemical analysis, mechanical performance, metal structure, the decay resistance of pipe all do not change in it, and its original various performances are kept.

When 4, controlling the pyrocondensation footpath, the applying of outer tube and interior pipe realizes micro-interference, treat that outer tube is cooled to normal temperature, because the outer tube shrinkage makes outer tube embrace interior pipe tightly, presents high interference state, make adhesion enhancing between inner and outer pipe, its bond strength 〉=0.6MPa is far above CJ/T192-2004 " inner liner stainless steel multiple tube " standard techniques index, the bond strength 〉=0.2MPa between this standard-required inner and outer pipe.Will be better with the interior 304/ outer 20# steel heat exchanger tube that this method is produced than the heat transfer property of pure 304 stainless steel heat exchanger tubes;

5, the bimetal pipe of producing in this way, pipe bears bigger compression in it, has the ability of excellent stress corrosion resistant;

(4) description of drawings:

Fig. 1 is the structural representation after the outer tube reducing of the present invention;

Fig. 2 is a pipe necking end assembly welding plug structural representation of the present invention;

Fig. 3 is a pipe other end assembly welding vacuum pumping tool equipment structural representation of the present invention;

Fig. 4 is heating of pipe blank of the present invention, undergauge state sectional view.

(5) specific embodiment:

Referring to Fig. 1-Fig. 3, the present invention includes following steps:

1) see Fig. 1, with outer tube 1 one end reducings, making the necking end internal diameter is interior external diameter of pipe _{+ 0.10} ^{+ 0.20}, the other end remains unchanged;

2) interior pipe 2 outer surfaces, outer tube 1 inner surface are carried out processing of rust removing completely;

3) see Fig. 2, interior pipe 2 penetrated in the outer tube 1 that the outer tube necking end aligns with interior Guan Yiduan, and the plug 3 of assembly welding one band aperture 4;

4) see Fig. 3, other end assembly welding one vacuum pumping tool equipment 6 at inner and outer pipe, vacuum pumping tool equipment 6 front ends have vacuum orifice 7, the rear end has airtight and watertight padding 8, sealing gland 9 is pushed down airtight and watertight padding 8, make the inner and outer pipe of this end realize sealing, can vacuumize from vacuum orifice 7, the air in making between pipe and outer tube is taken away as far as possible entirely.Cost also can be saved so directly with the sealing of O type circle in vacuum pumping tool equipment of the present invention rear end.

5) see Fig. 3, connect a relief valve 5 in plug 3 backs by tube connector, aperture 4 one ends on the plug 3 communicate with interior pipe 2, the other end communicates with relief valve 5, in interior pipe 2, be connected with the clean water of pressure, behind relief valve 5, connect a flexible pipe again, make water receive tank (this water is reusable); If interior pipe is an austenitic stainless steel, its chloride ion content of the clean water in the interior pipe is answered≤25PPm;

6) be evacuated down to the 100-150mm water column between inner and outer pipe, (pressure of clean water will be adjusted according to the material of interior pipe and the size of caliber here after clean water pressure in the interior pipe reached 2.5-10MPa, 90-95% with the inner tube material yield exceeds, as interior pipe is the stainless steel tube of φ 19 * 0.5, hydraulic pressure is 4.5-5.5MPa, and interior pipe is the L of ф 19 * 1 ₂Commercial-purity aluminium, hydraulic pressure is 2.5-3.0MPa), the inner and outer pipes that cover is got togather heats from the outer tube necking end, once heat 600-800mm, (the outer tube material initial forging temperature here was conventional technological parameter, is 1000--1050 ℃ as 20# after its temperature reached the outer tube material initial forging temperature, 16Mn is 1050 ℃--1150 ℃), deliver to rapidly on the size reducing machine, the external pressure reducing is fitted outer tube wall and outer wall of inner tube.Undergauge length is than the short 50-60mm of heated length, heat undergauge (see figure 5) piecemeal piecemeal,, make in the process and remain vacuum between inner and outer pipe until with whole pipe completion of processing, remain the pressure of clean water in the interior pipe, drop to below 120--160 ℃ until the outer tube temperature;

7) cut off plug 3 and vacuum pumping tool equipment 6, with bimetal pipe drawing on drawbench, shaping.

Vacuum pumping tool equipment 6 and all belong to existing mature technology for the clean water pressurization (as utilizing the pressurization of accumulator and high-pressure hydraulic pump) in the interior pipe does not repeat them here.

Change the shape of pyrocondensation dies cavity, also can make the double-level-metal tube outer surface band lengthways of rod of output, or band shape muscle, or band waveform shape.

Claims

1, a kind of production process of double-layer is characterized in that may further comprise the steps:

1) with outer tube (1) one end reducing, making the necking end internal diameter is interior external diameter of pipe+0.10+0.20, and the other end remains unchanged;

2) interior pipe (2) outer surface, outer tube (1) inner surface are carried out processing of rust removing completely;

3) interior pipe (2) is penetrated in the outer tube (1), the outer tube necking end aligns with interior Guan Yiduan, and the plug (3) of assembly welding one band aperture (4);

4) at other end assembly welding one vacuum pumping tool equipment (6) of inner and outer pipe;

5) in interior pipe (2), be connected with the clean water of pressure;

6) vacuumize back heating, undergauge between inner and outer pipe;

7) cut off plug (3) and vacuum pumping tool equipment (6), with bimetal pipe drawing on drawbench, shaping.

2, according to the described production process of double-layer of claim 1, it is characterized in that connecting a relief valve (5) in plug (3) back, aperture (4) one ends on the plug (3) communicate with interior pipe (2), and the other end communicates with relief valve (5).

3, according to the described production process of double-layer of claim 1, it is characterized in that heating, the method for undergauge is that the inner and outer pipes that cover gets togather is heated from the outer tube necking end, once heat 600-800mm, after its temperature reaches the outer tube material initial forging temperature, deliver to rapidly on the size reducing machine, the external pressure reducing, undergauge length is than the short 50-60mm of heated length, heat undergauge piecemeal piecemeal, until managing completion of processing with whole.