CN104438471A - Method for eliminating assembly gap between base and lining of composite tube - Google Patents

Abstract

The invention provides a method for eliminating the assembly gap between a base and a lining of a composite tube. According to the method, force is applied to the inner portion of a lining tube to enable the lining tube to deform plastically, so that the gap between a base tube and the lining tube is eliminated and the lining tube is made to contract freely in the axial direction. By the adoption of a pre-pressing mode, the base tube is made to make contact with the inner wall and the outer wall of the lining tube and the gap between the base tube and the lining tube is eliminated; meanwhile, due to the fact that the lining tube contracts freely in the axial direction, axial residual stress generated after compositing is reduced; after pre-pressing, underwater deflagration compositing is conducted on a base assembly structure and a lining assembly structure. According to bonding strength tests, the maximum unevenness of the bonding strength of the composite tube is reduced to 7% from 54%; according to residual stress tests, the axial residual stress is also greatly reduced, and the reduction amplitude is larger than 10 MPa generally.

Description

A kind of method eliminating multiple tube base/lining fit-up gap

Technical field

The invention belongs to forming materials field, relating to by improving base/eccentric method improving detonation composite effect under water of lining assembling.

Background technology

Detonation composite machine formula composite bimetal pipe produces underwater blast wave by primacord the base/bushing pipe assembled to be occurred (base tube is outer tube, plays pressure-bearing effect, and bushing pipe is interior pipe, plays withstand voltage effect) that relative elastic-plastic deformation reaches laminating under water.If base/uneven meeting in lining fit-up gap causes the distribution of forces between base/lining uneven, the uniformity of base/lining bond strength and change in size after multiple tube compound finally cannot be ensured.

In existing base/lining compound assembling process, lie in a horizontal plane on composite frame after base/lining assembling and carry out compound.Due to bushing pipe deadweight impact after mounting above pipe base/lining gap maximum, and Fang Ji/lining there occurs and contacts with each other under the tube, the bias assembling of bushing pipe simultaneously result also in primacord and there occurs bias (the ultimate range D of primacord above pipe relative to base tube _maxbe greater than the minimum range D of primacord below pipe _min), the bias of base/lining assembling makes the contact condition on cross section between base/lining different, the power that primacord bias makes bushing pipe be applied on base tube is different, due to shock wave, to have pressure large, the feature that time is short, therefore carry out under base/lining contact condition is different with interaction force detonation compound can cause compound after the bond strength of multiple tube uneven, easily there is the phenomenon that ovality and size exceed standard in multiple tube, and due to shock wave pressure large, time is short, so compound tense bushing pipe has little time free shrink vertically, consequently after compound there is larger axial residual stress in bushing pipe.

Summary of the invention

The object of the present invention is to provide a kind of method eliminating multiple tube base/lining fit-up gap, make bushing pipe radially eliminate base tube and bushing pipe gap with the free plastic deformation of axial generation by suppressing in advance, and reduce the axial residual stress of bushing pipe after compound.

For achieving the above object, present invention employs following technical scheme:

A kind of method eliminating multiple tube base/lining fit-up gap, the method makes bushing pipe generation plastic deformation by applying hydraulic pressure in bushing pipe, thus eliminate the gap of base tube and bushing pipe and make bushing pipe free shrink vertically, reduce the axial residual stress of bushing pipe after compound.

Described method specifically comprises the following steps:

1) first intercept and to save external seal gripping section that short tube suppresses as hydraulic press with two of base tube same specification (both internal-and external diameter identical or external diameter is identical with wall thickness) or as the jiont treatment section (by short tube one end cover plate for sealing, be then installed into, outlet valve) connecting water pump;

2) assembling of bushing pipe, base tube and short tube

Bushing pipe length being greater than base tube penetrates in described base tube, base tube is all exposed in the two ends of bushing pipe, the part that bushing pipe exposes base tube is divided into reserved indentation section and short tube construction section, reserved indentation section is adjacent with base tube, two joint short tubes are enclosed within corresponding short tube construction section respectively, and make one end of described short tube concordant with the end of bushing pipe, then ensureing to adopt soldering and sealing mode to be welded with corresponding short tube end bushing pipe end under the state that bushing pipe end is concordant with short tube end, and butt welded seam carries out x-ray examination, thus ensure weldquality;

3) through step 2) after, in bushing pipe, inject liquid, utilize hydraulic pressure to make bushing pipe generation plastic deformation, and radially expand, thus eliminate the gap of base tube and bushing pipe;

4) through step 3) after, shed hydraulic action, the end along base tube cuts out the part that bushing pipe exposes base tube, and at this moment base/lining gap is zero substantially, so just obtains gapless base/lining assembling pipe.

Length=base tube length+2 α L+2L of bushing pipe _short, L _shortfor the length of short tube, α L is the length of reserved indentation section, and α is reserved coefficient of discharge, and it is the theory monolateral indent of bushing pipe when there is described plastic deformation that α at least equals 1, L.

The value of described α is that the value of 1.2, α should be not excessive, otherwise, easily there is external drum phenomenon in reserved indentation section in bushing pipe contraction process.

Described step 3) specifically comprise the following steps:

3.1) bushing pipe, base tube and short tube are put into hydraulic press after having assembled and suppress district, adopt the sealing device of hydraulic press to realize external seal on two joint short tubes;

3.2) through step 3.1) after, be vented to water filling in bushing pipe by hydraulic press, then suppress, make bushing pipe generation plastic deformation, and radially expand, thus eliminate the gap of base tube and bushing pipe.

In step 3.2) front, with rubber blanket will reserve indentation section parcel, then with adhesive tape, rubber blanket is fastened, object for prevent hydraulic press from suppressing and suppress terminate after dismounting hydraulic press time water enter between base tube and bushing pipe; After shedding hydraulic action, remove rubber blanket, and then cut out the part that bushing pipe exposes base tube along the end of base tube.

The length of described short tube is 100 ~ 300mm, is preferably 200mm.

The length of described rubber blanket is 1.5 α L, α is reserved coefficient of discharge, and L is the theory monolateral indent of bushing pipe when there is described plastic deformation, and the width of rubber blanket is 1.2C, and C is base tube girth, and the thickness of rubber blanket is 2 ~ 5mm.

The described actual conditions suppressed is: the most high hydraulic pressure suppressed can make bushing pipe cross section reach complete yield, to reach after most high hydraulic pressure at least pressurize 5min.

Beneficial effect of the present invention is embodied in:

The present invention adopts and suppresses mode in advance, namely bushing pipe is made circumferentially with axially free plastic deformation to occur by hydraulic pressure (such as water pressure generation), in the process suppressed in advance, bushing pipe reaches yield situation, bushing pipe starts to expand, base/serve as a contrast all is contacted with each other at circumferencial direction, because bushing pipe there occurs larger permanent deformation after shedding pressure, and to make to unload rear base/lining gap be zero substantially, this just covert eccentric degree reducing base/lining gap.

Further, when bushing pipe reaches surrender, bushing pipe circumferentially expands, and certainly will will shrink vertically, because hydraulic loaded speed is low, and adopt and be more than or equal to 5min and carry out pressurize, therefore bushing pipe can fully be out of shape in this process vertically, which solves due to bushing pipe in detonation compound be out of shape vertically insufficient cause compound after the excessive problem of axial residual stress.

Accompanying drawing explanation

Fig. 1 is existing base/lining bias assembling schematic diagram;

Fig. 2 is that the present invention eliminates base/lining gap assembling schematic diagram;

Fig. 3 is the assembling schematic diagram after the present invention eliminates gap;

In figure: 1 is bushing pipe, 2 is base tube, and 3 is rubber blanket, and 4 is short tube, and 5 is soldering and sealing weld seam, and 6 is maximal clearance place, and 7 is sealing ring, and 8 is contact surface, and 9 is primacord, and 10 is reserved indentation section.

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention is elaborated.

In order to eliminate the difference of the composite effect that base/lining gap inhomogeneities is brought, the present invention makes bushing pipe generation plastic deformation by water pressure generation thus reaches elimination base/lining gap and make the object of bushing pipe free shrink vertically.

Concrete grammar:

First intercept and save at two of 100 ~ 300mm the external seal gripping section that short tube 4 suppresses as hydraulic press with base tube 2 same specification (internal-and external diameter is identical or external diameter is identical with wall thickness) length;

Secondly processing length is 1.5 α L, and width is 1.2C, and wall thickness is two pieces of rubber blankets of 2 ~ 5mm, and L is the monolateral indent of theory that bushing pipe calculates when there is described plastic deformation; C is base tube girth;

Then base tube, bushing pipe, short tube and rubber blanket are assembled with reference to mode shown in Fig. 2, and soldering and sealing is carried out at bushing pipe 1 two ends and respective side short tube 4 outer end, wherein length=base tube length+2 α L+2L of bushing pipe _short; The detailed process of assembling and soldering and sealing is:

Bushing pipe 1 is penetrated in base tube 2, base tube is all exposed in the two ends of bushing pipe, the part that bushing pipe exposes base tube is divided into reserved indentation section 10, and (length is α L, the value of α is 1.2) and short tube construction section, reserved indentation section is adjacent with base tube 2, then two short tubes 4 are enclosed within respectively on corresponding short tube construction section, then ensureing to adopt soldering and sealing mode to be welded with corresponding short tube end (outer end) bushing pipe end under the state that bushing pipe end is concordant with short tube end, and butt welded seam carries out x-ray examination, thus ensure weldquality;

Then the bushing pipe assembled, base tube and short tube are put into hydraulic press and suppress district, the sealing device of hydraulic press is adopted to realize external seal on two joint short tubes, then rubber blanket 3 is rolled in the position of reserved indentation section, rubber blanket entirety is wound around by blend compounds band, and object is that anti-sealing enters between base tube and bushing pipe;

Carry out suppressing that (hydraulic press and short tube adopt external seal form to seal finally by hydraulic press, namely the sealing device of hydraulic press realizes the sealing with short tube by the expansion of exterior seal ring under radial pressure, axial in process can moving freely suppressed by hydraulic press, therefore it is adopted to suppress the free shrink that can ensure bushing pipe), require that the maximum pressure suppressed can make bushing pipe cross section reach complete yield, the highest hydraulic pressure value is calculated by formula (1) and (2) by the actual measurement mechanical performance data of bushing pipe:

$P_i={\mathrm{\σ}}_{\mathrm{si}}^{\′}\ln \frac{d_o+2\mathrm{\δ}}{d_i+2\mathrm{\δ}}---\left(1\right)$

${\mathrm{\σ}}_{\mathrm{si}}^{\′}={\mathrm{\σ}}_{\mathrm{si}}+E_i^{\′}\mathrm{\Δ\ϵ}\≈{\mathrm{\σ}}_{\mathrm{si}}+E_i^{\′}\frac{2\mathrm{\δ}}{d_o}---\left(2\right)$

Wherein: P _ifor maximum hydraulic pressure pressure; σ _sifor the yield strength of bushing pipe; E ' _ifor strengthening elastic modelling quantity; σ ' _sifor the flow stress of bushing pipe, d _ifor the internal diameter of bushing pipe; d _ofor the external diameter of bushing pipe; δ is base/serve as a contrast monolateral gap, and Δ ε represents plastic strain;

At least pressurize 5min when reaching maximum pressure (i.e. maximum hydraulic pressure pressure).Because maximum pressure only makes bushing pipe generation permanent plastic deformation only there is very little elastic deformation in base tube in this process, and therefore bushing pipe radially expands and eliminates base/lining gap, and freely shorten vertically and reduce axial residual stress, see Fig. 3.Remove rubber blanket after having beaten hydraulic pressure, cut out unnecessary bushing pipe and short tube along base tube pipe end, the base that is finally eliminated/lining gap and the confined state reducing axial residual stress.Under elimination base/lining gap state compound comparatively under Fig. 1 state the better reason of composite effect have following 2 points: one, eliminate base/lining gap can reduce base/lining and assemble the uneven degree of bond strength after the compound that bias causes, under state shown in Fig. 1, due to deadweight to affect base above pipe/lining gap large, and base/lining gap that contacts with each other is zero below pipe, even if under identical shock wave pressure, because bushing pipe meeting different from the contact condition of base tube causes at the interaction force of compound tense bushing pipe and base tube different, bond strength after compound between base/lining is different, otherwise the contact condition eliminated between the assembling Guan Ji/lining behind base/lining gap is basically identical, avoiding problems the problem of the multiple tube compound lack of homogeneity that base/lining bias is brought, two, under state shown in Fig. 1, directly detonation compound is under water carried out, because detonation compound under water has the advantages that impulsive force is large, action time is short, therefore bushing pipe axially cannot shrink completely, therefore there is larger axial residual stress at compound backsight inside pipe wall, otherwise after water pressure generation eliminates base/lining gap, carry out detonation compound under water again, because bushing pipe shrank vertically completely in the water pressure generation stage, therefore after compound, the inner axial residual stress of bushing pipe is less, and corrosion resistance and the anti-external applied load ability of the less then bushing pipe of the axial residual stress of bushing pipe are better.

Embodiment

Because the less base in base/lining gap/lining assembling is eccentric less on the impact of multiple tube composite quality.So first make bushing pipe circumferentially with axially sufficient plastic deformation occur by suppressing in advance to bushing pipe, object is axial residual stress behind elimination base/lining gap and reduction compound, and then carry out detonation compound under water according to combination process, bushing pipe so just can be avoided to assemble the eccentric composite quality problem caused.Concrete implementation step is:

(1) calculate according to the mechanical property measured data through type (1) of bushing pipe and formula (2) the maximum hydraulic pressure pressure eliminated needed for base/lining gap:

$P_i={\mathrm{\σ}}_{\mathrm{si}}^{\′}\ln \frac{d_o+2\mathrm{\δ}}{d_i+2\mathrm{\δ}}---\left(1\right)$

${\mathrm{\σ}}_{\mathrm{si}}^{\′}={\mathrm{\σ}}_{\mathrm{si}}+E_i^{\′}\mathrm{\Δ\ϵ}\≈{\mathrm{\σ}}_{\mathrm{si}}+E_i^{\′}\frac{2\mathrm{\δ}}{d_o}---\left(2\right)$

Wherein: P _ifor maximum hydraulic pressure pressure; σ _sifor the yield strength of bushing pipe; E ' _ifor strengthening elastic modelling quantity; σ ' _sifor the flow stress of bushing pipe, d _ifor the internal diameter of bushing pipe; d _ofor the external diameter of bushing pipe; δ is base/serve as a contrast monolateral gap, and Δ ε represents plastic strain; Be ￠ 219.1x10 according to base tube specification, material is L360; Bushing pipe specification is ￠ 197x2, and material is 316L, and base/serve as a contrast monolateral gap is 1mm (supposing that base tube/bushing pipe is coaxial), then the maximum hydraulic pressure pressure calculated is 7.5MPa.

(2) when supposing bushing pipe from reset condition to elimination base/lining gap (just contacting with base tube), the indent of bushing pipe is 2L, and the theory according to constancy of volume before and after bushing pipe change can show that L is:

$L=\frac{L_0}{2}(1-\frac{D_0^2-d_0^2}{D_1^2-d_1^2})---\left(3\right)$

Wherein: L ₀for bushing pipe reset condition length; D ₀and d ₀be respectively bushing pipe reset condition external diameter and internal diameter; D ₁and d ₁be respectively external diameter and the internal diameter of bushing pipe behind elimination base/lining gap.The reason of the change such as pressure of friction, bushing pipe wall thickness and effect is there is, so the indent 2L error of actual indent and calculating is generally within 20% between base/lining; Be ￠ 219.1x10 for specification, length is the base tube of 11.2m and specification is ￠ 197x2, and length is the bushing pipe of 11.2m, and calculating this bushing pipe indent by formula (3) is 118mm, and the indent of actual measurement is 120mm, the error of amount of calculation and actual measured amount is 1%.

(3) first intercepting with base tube same specification, length is the sealing position that two of 200mm save short tube and suppresses as hydraulic press, and next processing length is 1.5 α L, and width is 1.2C, and wall thickness is two pieces of rubber blankets of 2 ~ 5mm.Then base tube, bushing pipe, short tube and rubber blanket are assembled according to shown in Fig. 2, and soldering and sealing is carried out at bushing pipe two ends and short tube outer end.Wherein length=base tube length+2 α L+2L of bushing pipe _short(α is 1.2, L _shortget 200mm).Be example according to the bushing pipe of ￠ 197x2 in above-mentioned test, the overall length of bushing pipe should be 11.744m.

(4) base/lining gap is eliminated: after carbon steel pipe nipple (i.e. short tube), rubber blanket, base tube being assembled shown in Fig. 2, suppress in advance bushing pipe, the highest hydraulic pressure suppressed in advance is P _i, the dwell time is 5 minutes, finally sheds pressure, removes rubber blanket and cuts out carbon steel pipe nipple and unnecessary bushing pipe, obtains the base/lining assembling pipe eliminating gap.Suppress process: when hydraulic pressure reaches P _itime bushing pipe cross section reach complete yield, at this moment bushing pipe cross section starts to expand, and bushing pipe starts to shrink vertically, and when pressurize 5 minutes backsight tube outer surfaces are basic and base tube inner surface comes in contact, at this moment bushing pipe axial shrinkage also reaches maximum.When bushing pipe after unloading all belongs to permanent deformation except there is the outer major part distortion of very little resilience, base tube there occurs very little resilience equally, can think still to contact between base/lining or base/lining gap is very little can be approximated to be zero after therefore unloading.Gap after the base tube of ￠ 219.1x10 and the bushing pipe of ￠ 197x2 being suppressed in advance to process between base/lining is less than 0.1mm.

(5) base tube and bushing pipe are carried out soldering and sealing process: after being excised by unnecessary bushing pipe along base tube end by the assembling pipe after suppressing in advance, adopt the mode of argon arc welding to carry out pipe end soldering and sealing process.

(6) detonation technological parameter is under water adopted to carry out detonation compound the assembling pipe of two ends soldering and sealing.

(7) multiple tube after compound is intercepted the pipe nipple of 300mm to be processed into and to shear peeling strength and residual stress testpieces carries out bond strength and residual stress test, and measure the ovality after compound.

The test data that table 1. is tested

Remarks: above-mentioned test data is the test result after the base tube of 219.1x10 and the bushing pipe of ￠ 197x2 adopt Fig. 1 mode direct combination and Fig. 2 mode (eliminating base/lining gap) to process respectively again after compound, the multiple tube bond strength eliminating gap does not as can be seen from Table 1 eliminate that the compound uniformity of gap and direct combination is good (to be shown through bond strength test, the maximum unevenness of bond strength not eliminating base/lining gap is about 54%, and the maximum unevenness of bond strength is about 7% after eliminating base/lining gap, this shows that the uniformity of bond strength after eliminating gap is greatly improved), the axial residual stress of the multiple tube in elimination gap does not eliminate gap and direct combination has obvious reduction, its reduction amplitude is generally greater than 10MPa (in table 1, reduction amplitude is 16.8Mpa), the multiple tube ovality in elimination gap does not eliminate gap and direct combination has obvious reduction.

Maximum unevenness=(maximum combined intensity measurement value-minimum bond strength measured value)/average bonding strength measured value.

Claims (9)

1. eliminate the method for multiple tube base/lining fit-up gap for one kind, it is characterized in that: the method makes bushing pipe generation plastic deformation by applying hydraulic pressure in bushing pipe (1), thus eliminates the gap of base tube (2) and bushing pipe (1) and make bushing pipe (1) free shrink vertically.

2. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 1, is characterized in that: described method specifically comprises the following steps:

1) first intercepting saves short tube (4) with two of base tube (2) same specification;

2) assembling of bushing pipe, base tube and short tube

The bushing pipe (1) length being greater than base tube (2) penetrates in described base tube, base tube is all exposed in the two ends of bushing pipe, the part that bushing pipe exposes base tube is divided into reserved indentation section (10) and short tube construction section, reserved indentation section is adjacent with base tube, two joints short tube (4) are enclosed within corresponding short tube construction section respectively, and make one end of described short tube concordant with the end of bushing pipe, then bushing pipe end is welded with corresponding short tube end;

3) through step 2) after, in bushing pipe (1), inject liquid, utilize hydraulic pressure to make bushing pipe generation plastic deformation, and radially expand, thus eliminate the gap of base tube (2) and bushing pipe (1);

4) through step 3) after, shed hydraulic action, the end along base tube (2) cuts out the part that bushing pipe (1) exposes base tube.

3. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 2, is characterized in that: length=base tube length+2 α L+2L of bushing pipe _short, L _shortfor the length of short tube, α L is the length of reserved indentation section, and α is reserved coefficient of discharge, and it is the theory monolateral indent of bushing pipe when there is plastic deformation that α at least equals 1, L.

4. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 3, is characterized in that: the value of described α is 1.2.

5. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 2, is characterized in that: described step 3) specifically comprise the following steps:

3.1) bushing pipe, base tube and short tube are put into hydraulic press after having assembled and suppress district, adopt the sealing device of hydraulic press to realize external seal on two joints short tube (4);

3.2) through step 3.1) after, be vented to bushing pipe (1) interior water filling by hydraulic press, then suppress, make bushing pipe generation plastic deformation, and radially expand, thus eliminate the gap of base tube (2) and bushing pipe (1).

6. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 5, it is characterized in that: in step 3.2) front, indentation section (10) parcel will be reserved with rubber blanket (3), then with adhesive tape, rubber blanket will be fastened; After shedding hydraulic action, remove rubber blanket, and then cut out the part that bushing pipe exposes base tube along the end of base tube.

7. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 5, is characterized in that: the length of described short tube is 100 ~ 300mm.

8. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 5, it is characterized in that: the length of described rubber blanket is 1.5 α L, α is reserved coefficient of discharge, L is the theory monolateral indent of bushing pipe when there is plastic deformation, the width of rubber blanket is 1.2C, C is base tube girth, and the thickness of rubber blanket is 2 ~ 5mm.

9. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 5, it is characterized in that: described in the actual conditions suppressed be: the most high hydraulic pressure suppressed can make bushing pipe (1) cross section reach complete yield, to reach after most high hydraulic pressure at least pressurize 5min.