CN104438471B - A kind of method eliminating multiple tube base/lining fit-up gap - Google Patents

Abstract

The present invention provides a kind of method eliminating multiple tube base/lining fit-up gap: the method makes bushing pipe generation plastic deformation by applying effect in bushing pipe, thus eliminating the gap of base tube and bushing pipe, and makes bushing pipe free shrink vertically；The present invention adopts mode of suppressing in advance, base tube and bushing pipe inside and outside wall are come in contact, eliminate the gap between base tube and bushing pipe, simultaneously, free shrink is there occurs vertically due to bushing pipe, therefore axial residual stress after reducing compound, after suppressing in advance, base/lining assembling structure is carried out detonation compound under water, combined strength test shows, the maximum unevenness of bond strength of gained multiple tube is reduced to 7% from 54%, testing axial residual stress through overstrain to be greatly reduced, its reduction amplitude is generally higher than 10MPa。

Description

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

Technical field

The invention belongs to material forming field, relate to by improving the method that base/lining assembling bias improves detonation composite effect under water。

Background technology

Detonation composite machine formula composite bimetal pipe is to produce underwater blast wave by primacord to make the base assembled/bushing pipe occur relative elastic-plastic deformation to reach (base tube is outer tube, plays pressure-bearing effect, and bushing pipe is interior pipe, plays pressure effect) of laminating under water。If base/uneven meeting in lining fit-up gap causes that the distribution of forces between base/lining is 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 in after base/lining assembling and composite frame carries out compound。Owing to above the impact pipe after mounting of bushing pipe deadweight, base/lining gap is maximum, and Fang Ji/lining there occurs and contacts with each other under the tube；The simultaneously eccentric assembling of bushing pipe result also in primacord and there occurs bias relative to base tube (primacord is from the ultimate range D above pipe_maxMore than primacord from the minimum range D below pipe_min), the bias of base/lining assembling makes the contact condition difference on cross section between base/lining, primacord bias makes the power that bushing pipe is applied on base tube different, due to shock wave, to have pressure big, the feature that time is short, therefore under base/lining contact condition is different with interaction force, the bond strength of multiple tube after detonation compound can cause compound is carried out uneven, easily there is the phenomenon that ovality and size exceed standard in multiple tube, and owing to shock wave pressure is big, time is short, so compound tense bushing pipe has little time free shrink vertically, its result is that after compound, bushing pipe exists bigger axial residual stress。

Summary of the invention

It is an object of the invention to provide a kind of method eliminating multiple tube base/lining fit-up gap, occur so that bushing pipe free plastic deformation to eliminate base tube and bushing pipe gap radially and axially by suppressing in advance, and reduce the bushing pipe axial residual stress after compound。

For reaching above-mentioned purpose, present invention employs techniques below 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 eliminating the gap of base tube and bushing pipe and making bushing pipe free shrink vertically, reduces the axial residual stress of bushing pipe after compound。

Described method specifically includes following steps:

1) first intercept with base tube same specification (both internal-and external diameter had been identical or external diameter and wall thickness identical) the external seal gripping section suppressed as hydraulic press of two joint short tubes or as the joint construction section (by short tube one end cover plate for sealing, be then installed into, outlet valve) of connection water pump；

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

Length is penetrated in described base tube more than the bushing pipe of base tube, the two ends of bushing pipe are exposed independent from base tube, bushing pipe exposes the part of base tube and is divided into reserved indentation section and short tube construction section, reserved indentation section is adjacent with base tube, save short tube by two and be respectively fitted on the short tube construction section of correspondence, and make one end of described short tube concordant with the end of bushing pipe, then soldering and sealing mode is adopted to be welded with corresponding short tube end bushing pipe end when guarantee bushing pipe end is concordant with short tube end, and butt welded seam carries out x-ray examination, thus ensureing weldquality；

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

4) through step 3) after, shedding hydraulic action, the end along base tube cuts out bushing pipe and exposes the part of base tube, and at this moment base/lining gap is substantially zeroed, thus obtains gapless base/lining assembling pipe。

The length of bushing pipe=base tube length+2 α L+2L_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 α is the bushing pipe monolateral indent of theory when there is described plastic deformation at least equal to 1, L。

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

Described step 3) specifically include following steps:

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

3.2) through step 3.1) after, by hydraulic press to water filling in bushing pipe aerofluxus, then suppress, make bushing pipe generation plastic deformation, and be radially expanded, thus eliminating the gap of base tube and bushing pipe。

In step 3.2) front, with rubber blanket, reserved indentation section to be wrapped up, then be wound fixing to rubber blanket with adhesive tape, purpose is for dismantling hydraulic press after preventing hydraulic press from suppressing and suppressing end time, water enters between base tube and bushing pipe；After shedding hydraulic action, remove rubber blanket, then cut out bushing pipe along the end of base tube again and expose the part of base tube。

The length of described short tube is 100～300mm, it is preferred to 200mm。

The length of described rubber blanket is 1.5 α L, α is reserved coefficient of discharge, and L is the bushing pipe monolateral indent of theory 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 enables to bushing pipe cross section and reaches complete yield, reaches after most high hydraulic pressure at least pressurize 5min。

Beneficial effects of the present invention is embodied in:

The present invention adopts mode of suppressing in advance, namely make bushing pipe circumferentially by hydraulic pressure (such as water pressure generation) and free plastic deformation axially occurs, in the process suppressed in advance, bushing pipe reaches yield situation, bushing pipe starts to expand, base/lining is made all to contact with each other at circumferencial direction, owing to bushing pipe there occurs bigger permanent deformation after shedding pressure, and after making unloading, base/lining gap is substantially zeroed, and this is with regard to the covert eccentric degree reducing base/lining gap。

Further, when bushing pipe reaches to surrender, bushing pipe circumferentially expands, and certainly will shrink vertically, owing to hydraulic loaded speed is low, and adopt and carry out pressurize be more than or equal to 5min, therefore bushing pipe can fully deform in this process vertically, which solves owing in detonation compound, bushing pipe axially deforms insufficient problem causing that after compound, axially residual stress is excessive。

Accompanying drawing explanation

Fig. 1 is existing base/lining eccentric 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 reaching eliminate base/lining gap and make the purpose of bushing pipe free shrink vertically。

Concrete grammar:

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

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 bushing pipe 1 two ends and respective side short tube 4 outer end are carried out soldering and sealing, the wherein length of bushing pipe=base tube length+2 α L+2L_Short；The detailed process of assembling and soldering and sealing is:

Bushing pipe 1 is penetrated in base tube 2, the two ends of bushing pipe are exposed independent from base tube, bushing pipe exposes the part of base tube and is divided into reserved indentation section 10 (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 respectively fitted on the short tube construction section of correspondence, then soldering and sealing mode is adopted to be welded with corresponding short tube end (outer end) bushing pipe end when guarantee bushing pipe end is concordant with short tube end, and butt welded seam carries out x-ray examination, thus ensureing weldquality；

Then the bushing pipe assembled, base tube and short tube are put into hydraulic press and suppress district, the sealing device adopting hydraulic press saves two and realizes external seal on short tube, then rubber blanket 3 is rolled in the position of reserved indentation section, rubber blanket entirety is wound by blend compounds band, and purpose enters between base tube and bushing pipe for preventing water；

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 exterior seal ring expansion under radial pressure, hydraulic press axially can move freely in suppressing process, therefore it is adopted to suppress the free shrink that ensure that bushing pipe), requiring that the maximum pressure suppressed enables to bushing pipe cross section and reaches 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_siYield strength for bushing pipe；E '_iFor strengthening elastic modelling quantity；σ '_siFor the flow stress of bushing pipe, d_iInternal diameter for bushing pipe；D_oExternal diameter for 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)。Only making bushing pipe generation permanent plastic deformation in this process due to maximum pressure and only small elastic deformation only occurs base tube, therefore bushing pipe is radially expanded and eliminates base/lining gap, and axially from being reduced axial residual stress by shortening, referring to Fig. 3。Remove rubber blanket after having beaten hydraulic pressure, cut out unnecessary bushing pipe and short tube along base tube pipe end, finally give elimination base/lining gap and reduce the confined state of axial residual stress。Under elimination base/lining gap state, under compound relatively Fig. 1 state, the better reason of composite effect has following 2 points: one, eliminates base/lining gap and can reduce the degree that after base/lining assembles the compound that bias causes, bond strength is uneven, under state shown in Fig. 1, due to deadweight to affect base above pipe/lining gap big, and base/lining gap that contacts with each other is zero below pipe, even if under identical shock wave pressure, owing to bushing pipe meeting different from the contact condition of base tube causes that the interaction force at compound tense bushing pipe Yu base tube is different, after compound, the bond strength between base/lining is different；Otherwise it is basically identical to eliminate the contact condition between the assembling Guan Ji/lining behind base/lining gap, the problem that avoiding problems the multiple tube compound lack of homogeneity that base/lining bias is brought；Two, under state shown in Fig. 1, detonation compound under water it is made directly, owing to detonation compound under water has the advantages that impulsive force is big, action time is short, therefore bushing pipe axially cannot shrink completely, therefore there is bigger 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, owing to bushing pipe shrank vertically completely in the water pressure generation stage, therefore after compound, bushing pipe inner shaft is less to residual stress, and corrosion resistance and the anti-external applied load ability of the more little then bushing pipe of the axial residual stress of bushing pipe are more good。

Embodiment

Owing to the more little base in base/lining gap/lining assembling is eccentric more little on the impact of multiple tube composite quality。Sufficient plastic deformation circumferentially and is axially there is so that bushing pipe so first passing through to suppress in advance to bushing pipe, purpose is axial residual stress after eliminating base/lining gap and reducing compound, then carry out detonation compound under water according still further to combination process, thus can avoid the composite quality problem that bushing pipe assembling bias causes。Concrete enforcement step is:

(1) calculate, according to 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_siYield strength for bushing pipe；E '_iFor strengthening elastic modelling quantity；σ '_siFor the flow stress of bushing pipe, d_iInternal diameter for bushing pipe；D_oExternal diameter for bushing pipe；δ is base/serve as a contrast monolateral gap, and Δ ε represents plastic strain；Being ￠ 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 (assuming that base tube/bushing pipe is coaxial), then the maximum hydraulic pressure pressure calculated is 7.5MPa。

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

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

Wherein: L₀For bushing pipe initial condition length；D₀And d₀Respectively bushing pipe initial condition external diameter and internal diameter；D₁And d₁Respectively eliminate external diameter and the internal diameter of bushing pipe behind base/lining gap。The reason that the pressure etc. of friction, bushing pipe wall thickness and effect changes is there is, so the indent 2L error of actual indent and calculating is typically within 20% between base/lining；It is ￠ 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 surveyed is 120mm, the error of amount of calculation and actual measured amount is 1%。

(3) first intercepting the sealing position suppressed with the two joint short tubes that base tube same specification, length are 200mm as hydraulic press, 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。Then base tube, bushing pipe, short tube and rubber blanket are assembled shown in Fig. 2, and bushing pipe two ends and short tube outer end are carried out soldering and sealing。The wherein length of bushing pipe=base tube length+2 α L+2L_Short(α is 1.2, L_ShortTake 200mm)。Being 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, bushing pipe being suppressed in advance, 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 reached complete yield, at this moment bushing pipe cross section starts to expand, and bushing pipe starts to shrink at vertically, comes in contact with base tube inner surface when 5 minutes backsight tube outer surfaces of pressurize are basic, and at this moment bushing pipe axial shrinkage also reaches maximum。When after unloading, bushing pipe major part deformation except there is only small resilience except belongs to permanent deformation, base tube there occurs only small resilience equally, therefore it is believed that still contact between base/lining or base/lining gap is only small can be approximated to be zero after unloading。After in advance the base tube of ￠ 219.1x10 and the bushing pipe of ￠ 197x2 are suppressed process, the gap between base/lining is less than 0.1mm。

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

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

(7) pipe nipple of the multiple tube intercepting 300mm after compound is processed into shearing peeling strength and residual stress testpieces carries out bond strength and residual stress test, and measure the ovality after compound。

The test data of table 1. test

Remarks: above-mentioned test data is the base tube of 219.1x10 and the bushing pipe of ￠ 197x2 is respectively adopted after Fig. 1 mode direct combination and Fig. 2 mode (eliminating base/lining gap) process the test result after compound again, the multiple tube bond strength eliminating gap as can be seen from Table 1 do not eliminate gap and the compound uniformity of direct combination good (combined strength test shows, 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 after eliminating gap, the uniformity of bond strength is greatly improved), the axial residual stress of multiple tube eliminating gap does not eliminate gap and direct combination has obvious reduction, its reduction amplitude is generally higher than 10MPa (in table 1, reduction amplitude is 16.8Mpa), the multiple tube ovality eliminating 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 (8)

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

Described method specifically includes following steps:

1) two joints short tube (4) with base tube (2) same specification are first intercepted；

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

Length is penetrated in described base tube more than the bushing pipe of base tube (2) (1), the two ends of bushing pipe are exposed independent from base tube, bushing pipe exposes the part of base tube and is divided into reserved indentation section (10) and short tube construction section, reserved indentation section is adjacent with base tube, save short tube (4) by two and be respectively fitted on the short tube construction section of correspondence, 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 be radially expanded, thus eliminating the gap of base tube (2) and bushing pipe (1)；

4) through step 3) after, shedding hydraulic action, the end along base tube (2) cuts out bushing pipe (1) and exposes the part of base tube。

2. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 1, it is characterised in that: the length of bushing pipe=base tube length+2 α L+2L_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 α is the bushing pipe monolateral indent of theory when there is plastic deformation at least equal to 1, L。

3. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 2, it is characterised in that: the value of described α is 1.2。

4. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 1, it is characterised in that: described step 3) specifically include following steps:

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

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

5. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 4, it is characterized in that: in step 3.2) front, with rubber blanket (3), reserved indentation section (10) is wrapped up, then be wound fixing to rubber blanket with adhesive tape；After shedding hydraulic action, remove rubber blanket, then cut out bushing pipe along the end of base tube again and expose the part of base tube。

6. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 4, it is characterised in that: the length of described short tube is 100～300mm。

7. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 4, 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 bushing pipe monolateral indent of theory 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。

8. a kind of method eliminating multiple tube base/lining fit-up gap according to claim 4, it is characterized in that: described in the actual conditions suppressed be: the most high hydraulic pressure suppressed enables to bushing pipe (1) cross section and reaches complete yield, reaches after most high hydraulic pressure at least pressurize 5min。