CN102390002A - Automatic submerged-arc welding method for large insertion-type adapting pipe on cone - Google Patents

Automatic submerged-arc welding method for large insertion-type adapting pipe on cone Download PDF

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Publication number
CN102390002A
CN102390002A CN2011100774691A CN201110077469A CN102390002A CN 102390002 A CN102390002 A CN 102390002A CN 2011100774691 A CN2011100774691 A CN 2011100774691A CN 201110077469 A CN201110077469 A CN 201110077469A CN 102390002 A CN102390002 A CN 102390002A
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China
Prior art keywords
cone
welding
weld
weld seam
adapter
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Granted
Application number
CN2011100774691A
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Chinese (zh)
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CN102390002B (en
Inventor
傅育文
韩国富
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Shanghai Boiler Works Co Ltd
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Shanghai Boiler Works Co Ltd
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Priority to CN201110077469.1A priority Critical patent/CN102390002B/en
Publication of CN102390002A publication Critical patent/CN102390002A/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00Arc welding or cutting
    • B23K9/02Seam welding; Backing means; Inserts
    • B23K9/028Seam welding; Backing means; Inserts for curved planar seams
    • B23K9/0282Seam welding; Backing means; Inserts for curved planar seams for welding tube sections
    • B23K9/0286Seam welding; Backing means; Inserts for curved planar seams for welding tube sections with an electrode moving around the fixed tube during the welding operation
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00Arc welding or cutting
    • B23K9/18Submerged-arc welding
    • B23K9/186Submerged-arc welding making use of a consumable electrodes

Abstract

The invention discloses an automatic submerged-arc welding method for a large insertion-type adapting pipe on a cone, which comprises the following steps: (1) drilling the side wall of the cone; (2) inserting the adapting pipe into the cone, and welding a circle of annular steel gasket at the joint of the outer side of the cone and the adapting pipe; (3) respectively blocking up both ends of the large opening and the small opening of the cone; (4) welding a steel pipe with an angular surface at the position of the adapting pipe of the inner wall of the cone; (5) preheating before the welding is performed; (6) welding a welding seam between the cone and the adapting pipe by adopting an automatic saddle-shaped submerged-arc welding machine; (7) performing dehydrogenation treatment after the welding is completed; and (8) excluding the surplus height of the welding seam of the inner wall, and polishing until the welding seam is smooth. In the automatic submerged-arc welding method for the insertion-type large adapting pipe on the cone, the automatic saddle-shaped submerged-arc welding machine is adopted to weld the insertion-type adapting pipe and the cone from the inner wall, thereby, the welding production efficiency is greatly improved, and the influences of personal factors on the welding quality are reduced, so that the welding quality is effectively ensured, the problem that the welding seam of the adapting pipe is hard to repair is solved, the manufacturing cycle is shortened, and the manufacturing cost is saved.

Description

The Lincoln weld method of the big adapter of plug-in type on the cone
Technical field
The present invention relates to the Lincoln weld method of the big adapter of plug-in type on a kind of pressure vessels for the chemical industry cone, be used for the manufacturing of pressure vessels for the chemical industry, belong to welding technology field.
Background technology
Be illustrated in figure 1 as set in nozzle and cone welded structure sketch map, big adapter 12 of the plug-in type on the cone 11 and cone 11 axial right angle intersections form weld seam 13.To this type of welding point, the normal at present welding method that adopts is generally SMAW.Bigger for cone thickness, and the set in nozzle of diameter >=500mm, as adopting SMAW, not only welding efficiency is low, and welding quality is difficult to be guaranteed, in case and postwelding reprocess, it will be very big reprocessing difficulty.Therefore, employing can guarantee that the big adapter of plug-in type that welding quality can improve again on the method welding cone of welding efficiency is the problem that is worth very much research.
Summary of the invention
The purpose of this invention is to provide the big adapter of plug-in type that a kind of welding efficiency is high, welding quality is good, easy to operate (diameter >=500mm) and the Lincoln weld method of cone axis to the right angle intersection joint.
For realizing above purpose, the invention provides the Lincoln weld method of the big adapter of plug-in type on a kind of cone, this method comprises following concrete steps:
Step 1, the method that adopts gas cutting is at the cone side-wall hole, and this perforate inwall size is slightly larger than outer wall dimension;
Step 2 will be taken over and inserted cone, and in the cone outside and adapter junction, the annular steel sleeve of dress weldering one circle;
Step 3 is used the backing plate bed hedgehopping respectively with big mouthful of cone and osculum two ends, makes adapter axially perpendicular to the ground, the flange face built on stilts certain distance of adapter;
Step 4, the steel pipe on one section band of cone inwall adapter place dress weldering inclined-plane makes this steel shaft perpendicular to the ground to equally, in order to supporting shape of a saddle submerged arc welding machine;
Step 5 is carried out preheating in the side that annular steel sleeve is installed before the weldering, and preheat temperature is looked steel type and decided, and in whole welding process, all keeps this preheat temperature;
Step 6 adopts the weld seam between shape of a saddle submerged arc welding machine welding cone and the adapter;
Step 7 after welding is accomplished, adopts insulation material to coat the inwall weld seam, and adopts the infrared hydrogen that disappears of electricity to handle, and is heated to 250~350 ℃, insulation 2~4h;
Step 8 adopts carbon arc air gouging to exclude the inwall weld reinforcement, and polishes smooth; Remove outer wall circular steel sleeve, carry out magnetic particle inspection after polishing smooth.And weld the appropriate outside and strengthen high.
The Lincoln weld method of the big adapter of plug-in type on the above-mentioned cone, wherein, in the described step 1, cone attendes institute's perforate and has certain slope, the angle between gas cutting face and the vertical position (being the position of vertical ground), promptly the bevel for welding angle is 10~15 °.
The Lincoln weld method of the big adapter of plug-in type on the above-mentioned cone wherein, in described step 5, adopts electricity mode infrared or combustion gas to carry out preheating.
The Lincoln weld method of the big adapter of plug-in type on the above-mentioned cone wherein, in the described step 6, also comprises following concrete steps:
Step 6.1, elder generation's welding bottom weld seam: begin from bottommost, adopt progressively upwards welding of downhand position, every weldering one, shape of a saddle submerged arc welding machine turns an angle, and the fusion length of each layer is increased gradually; After the bottom weld seam reach a certain height, and the drop between the root of weld place of top weld seam will be more and more littler, when drop is less than 30~35mm, adopt the continuous welding of the whole circle of shape of a saddle submerged arc welding machine, till weld seam weldering in bottom is full between the two;
Step 6.2, welding top weld seam: adopt the discontinuous welding in downhand position as far as possible, allowed to have certain drop between solder joint and the top peak, but drop should be less than 30~35mm; Every weldering one, fusion length reduces gradually, till weld seam peak weldering in top is full.
The present invention makes adapter perpendicular to the ground, the axial right angle intersection of big adapter of plug-in type and cone big mouthful of cone and osculum two ends difference bed hedgehopping; Utilize auxiliary mould, adopt shape of a saddle Lincoln weld welding machine to carry out the welding of set in nozzle and cone, replaced welding rod arc soldering method commonly used from inwall; Improved welding production efficiency greatly; And reduced the influence of human factor, welding quality can effectively be guaranteed, avoided this type of to take over the problem that weld seam is difficult to reprocess welding quality; Shorten the manufacturing cycle, saved manufacturing cost.Technical scheme of the present invention is particularly useful for the big adapter of plug-in type (diameter >=500mm) weld to the Lincoln weld of right angle intersection joint with cone axis.
Description of drawings
Fig. 1 is the set in nozzle of traditional welding rod arc welding and the structural representation of cone.
Fig. 2 is the sketch map of the present invention through the big adapter of plug-in type on the cone of Lincoln weld welding.
Fig. 3 a ~ 3d is the adapter weld seam welding sequence sketch map of the Lincoln weld method of the big adapter of plug-in type on the cone of the present invention: Fig. 3 a represents the discontinuous welding of bottom weld seam; Fig. 3 b represents bottom and the discontinuous welding of middle part weld seam; The continuous welding of the whole circle of Fig. 3 c representative weld seam; Fig. 3 d represents the discontinuous welding of top weld seam.
The specific embodiment
Fig. 2, Fig. 3 a ~ 3d below in conjunction with accompanying drawing specify the specific embodiment of the present invention.
Embodiment:
Set in nozzle 22 sizes: interior diameter is 838mm, and wall thickness is 132mm, and material is the SA-182F11Cl2 steel; Cone 21 sizes: osculum internal diameter 3200mm, big mouthful of internal diameter 3800mm, cone wall thickness 120mm, material are the SA-387Gr11Cl2 steel.
Adopt the weld seam 28 between shape of a saddle submerged-arc welding method welding set in nozzle 22 and the cone 21, it comprises following concrete steps:
Step 1: adopt method perforate on cone 21 of gas cutting; This perforate inwall size is slightly larger than outer wall dimension; The bevel for welding angle is 12 °, and the bevel for welding angle is meant that cone 21 attendes institute's perforate and has certain slope, i.e. angle between gas cutting face and the vertical position (being the position of vertical ground).
Step 2: will take over 22 and insert cone 21, the as shown in Figure 2 assembling, and in the cone outside and adapter 22 junctions, the annular steel sleeve 23 of dress weldering one circle plays a supportive role.
Step 3: 21 big mouthfuls of cones and osculum two ends are used backing plate 26 bed hedgehoppings respectively; Present embodiment is selected for use and is put iron and carry out bed hedgehopping; Make adapter 22 axially vertical (in the prior art with ground 27; The welding plane is level normally, and welds the plane here), take over 22 flange face built on stilts certain distances;
Step 4: at one section steel pipe 24 of being with the inclined-plane of inwall adapter place dress weldering of cone 21; Make this steel pipe 24 axially same vertical with ground 27; In order to supporting shape of a saddle submerged arc welding machine 25, and through jig with welding machine 25 fixing with steel pipe 24 on, welding after accomplishing is pulled down steel pipe 24.
Step 5: adopt electric infrared preheating (also can adopt the mode of combustion gas to heat) in the side that annular steel sleeve 23 is installed before the weldering, preheat temperature is 150~200 ℃, and in whole welding process, all keeps this preheat temperature.This preheat temperature is by the material category decision of cone and adapter.
Step 6: adopt shape of a saddle submerged arc welding machine 25 welding cones 21 and take over the weld seam 28 between 22.This step further comprises:
Step 6.1: weld the bottom weld seam earlier: begin from bottommost, adopt progressively upwards welding of downhand position as far as possible, every weldering one, shape of a saddle submerged arc welding machine turns an angle, and the fusion length of each layer is increased gradually, shown in Fig. 3 (a) and 3 (b).Along with the arc length of each road weld seam increases gradually, allowed to have certain drop between solder joint and the minimum point, but both drops should be less than 35mm.After the bottom weld seam reach a certain height, and the drop between the root of weld place of top weld seam will be more and more littler, when drop is less than 35mm, adopt the continuous welding of the whole circle of shape of a saddle submerged arc welding machine, till weld seam weldering in bottom is full, shown in Fig. 3 (c) between the two.
Step 6.2: welding top weld seam: adopt the discontinuous welding in downhand position as far as possible, allowed to have certain drop between solder joint and the top peak, but drop should be less than 35mm.Every weldering one, fusion length reduces gradually, till weld seam peak weldering in top is full, shown in Fig. 3 (d).
Step 7: after welding is accomplished, adopt insulation material to coat the inwall weld seam, and adopt the infrared hydrogen that disappears immediately of electricity to handle, standard is for being heated to 250~350 ℃, insulation 2h.
Step 8: adopt carbon arc air gouging to exclude the inwall weld reinforcement, and polish smooth; Then, remove outer wall circular steel sleeve, carry out magnetic particle inspection after polishing smooth; And weld the appropriate outside and strengthen high.
Adopt the cone and the big adapter weld seam of plug-in type of said method welding, the postwelding ultrasonic flaw detection qualification rate reaches 98%, and has improved welding production efficiency greatly, has shortened the manufacturing cycle, has saved manufacturing cost.
Although content of the present invention has been done detailed introduction through above-mentioned preferred embodiment, will be appreciated that above-mentioned description should not be considered to limitation of the present invention.After those skilled in the art have read foregoing, for multiple modification of the present invention with to substitute all will be conspicuous.Therefore, protection scope of the present invention should be limited appended claim.

Claims (4)

1. the Lincoln weld method of the big adapter of plug-in type on the cone is characterized in that this method comprises following concrete steps:
Step 1, the method that adopts gas cutting is at cone (21) side-wall hole, and this perforate inwall size is slightly larger than outer wall dimension;
Step 2 will be taken over (22) and inserted cone (21), and in cone (21) outside and adapter (22) junction, dress weldering one circle annular steel sleeve (23);
Step 3 is used backing plate (26) bed hedgehopping respectively with big mouthful of cone (21) and osculum two ends, makes adapter (22) axially vertical with ground (27), takes over (22) flange face built on stilts certain distance;
Step 4, the steel pipe (24) on one section band of cone (21) inwall adapter place dress weldering inclined-plane makes this steel shaft to same vertical with ground (27), in order to supporting shape of a saddle submerged arc welding machine (25);
Step 5 is carried out preheating in the side that annular steel sleeve (23) is installed before the weldering, and in whole welding process, is all kept preheating;
Step 6 adopts shape of a saddle submerged arc welding machine (25) welding cone (21) and takes over the weld seam (28) between (22);
Step 7 after welding is accomplished, adopts insulation material to coat the inwall weld seam, and adopts the infrared hydrogen that disappears of electricity to handle, and is heated to 250~350 ℃, insulation 2~4h;
Step 8 adopts carbon arc air gouging to exclude the inwall weld reinforcement, and polishes smooth; Remove outer wall circular steel sleeve, carry out magnetic particle inspection after polishing smooth, and weld the appropriate outside and strengthen high.
2. the Lincoln weld method of the big adapter of plug-in type on the cone as claimed in claim 1; It is characterized in that in the described step 1, cone (21) attendes institute's perforate and has certain slope; Angle between gas cutting face and the vertical position, promptly the bevel for welding angle is 10~15 °.
3. the Lincoln weld method of the big adapter of plug-in type is characterized in that on the cone as claimed in claim 1, in described step 5, adopts electricity mode infrared or combustion gas to carry out preheating.
4. the Lincoln weld method of the big adapter of plug-in type is characterized in that on the cone as claimed in claim 1, in the described step 6, also comprises following concrete steps:
Step 6.1, elder generation's welding bottom weld seam: begin from bottommost, adopt progressively upwards welding of downhand position, every weldering one, shape of a saddle submerged arc welding machine turns an angle, and the fusion length of each layer is increased gradually; After the bottom weld seam reach a certain height, and the drop between the root of weld place of top weld seam will be more and more littler, when drop is less than 30~35mm, adopt the continuous welding of the whole circle of shape of a saddle submerged arc welding machine, till weld seam weldering in bottom is full between the two;
Step 6.2, welding top weld seam: adopt the discontinuous welding in downhand position as far as possible, allowed to have certain drop between solder joint and the top peak, but drop should be less than 30~35mm; Every weldering one, fusion length reduces gradually, till weld seam peak weldering in top is full.
CN201110077469.1A 2011-03-30 2011-03-30 Automatic submerged-arc welding method for large insertion-type adapting pipe on cone Active CN102390002B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201110077469.1A CN102390002B (en) 2011-03-30 2011-03-30 Automatic submerged-arc welding method for large insertion-type adapting pipe on cone

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201110077469.1A CN102390002B (en) 2011-03-30 2011-03-30 Automatic submerged-arc welding method for large insertion-type adapting pipe on cone
PCT/CN2012/071232 WO2012129994A1 (en) 2011-03-30 2012-02-16 Automatic submerged arc welding method for large inserted connecting tube on cone
PL403056A PL227290B1 (en) 2011-03-30 2012-02-16 Method for automatic submerged arc welding on the cone of the insert of the nozzle of large size
ZA2013/00785A ZA201300785B (en) 2011-03-30 2013-01-30 Automatic submerged arc welding method of large insertion nozzle on cone

Publications (2)

Publication Number Publication Date
CN102390002A true CN102390002A (en) 2012-03-28
CN102390002B CN102390002B (en) 2014-04-09

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PL (1) PL227290B1 (en)
WO (1) WO2012129994A1 (en)
ZA (1) ZA201300785B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102699551A (en) * 2012-06-29 2012-10-03 四川蓝星机械有限公司 Method for welding oblique inserted pipe of large chemical equipment
CN105382438A (en) * 2015-12-24 2016-03-09 哈尔滨锅炉厂有限责任公司 Novel oblique-inserted-pipe double-side welding groove and welding method
CN109366089A (en) * 2018-12-30 2019-02-22 中国石油天然气第建设有限公司 It is a kind of quick group of small-bore flange straight pipe to tooling
CN109822199A (en) * 2019-04-22 2019-05-31 晋西工业集团有限责任公司 A kind of process of continuous line welding
CN109894636A (en) * 2019-03-19 2019-06-18 兰州兰石重型装备股份有限公司 A kind of method of shape of a saddle pipe connecting flange height in quick determining cone

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58141870A (en) * 1982-02-19 1983-08-23 Sumikin Yousetsubou Kk Welding method of pipe
US4629853A (en) * 1984-02-24 1986-12-16 Esab Aktiebolag Apparatus for the internal welding of pipes
CN101041200A (en) * 2006-03-20 2007-09-26 上海锅炉厂有限公司 Method of welding the plug in type connection nozzle and the un-orthogonal crossed connection nozzle of the cylinder
CN101041201A (en) * 2006-03-20 2007-09-26 上海锅炉厂有限公司 Saddle type union melt welding with plug in type little connection nozzle
CN201471065U (en) * 2009-07-10 2010-05-19 江苏双良锅炉有限公司 Submerged arc welding machine head for small-diameter cylinder

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000107858A (en) * 1998-10-06 2000-04-18 Babcock Hitachi Kk Welded structure of pipe jointing part and welding method thereof
JP2003039167A (en) * 2001-07-30 2003-02-12 Hitachi Ltd Saddle type welding body, manufacturing method for saddle type welding body, working method for joining part, working device, and working control program
CN1947911A (en) * 2006-11-09 2007-04-18 上海锅炉厂有限公司 Automatic submerged-arc build-up welding process for drum surface round flange
CN201385194Y (en) * 2009-01-20 2010-01-20 甘肃中电科耀新能源装备有限公司 Special roller for manufacturing wind generating set tower

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58141870A (en) * 1982-02-19 1983-08-23 Sumikin Yousetsubou Kk Welding method of pipe
US4629853A (en) * 1984-02-24 1986-12-16 Esab Aktiebolag Apparatus for the internal welding of pipes
CN101041200A (en) * 2006-03-20 2007-09-26 上海锅炉厂有限公司 Method of welding the plug in type connection nozzle and the un-orthogonal crossed connection nozzle of the cylinder
CN101041201A (en) * 2006-03-20 2007-09-26 上海锅炉厂有限公司 Saddle type union melt welding with plug in type little connection nozzle
CN201471065U (en) * 2009-07-10 2010-05-19 江苏双良锅炉有限公司 Submerged arc welding machine head for small-diameter cylinder

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102699551A (en) * 2012-06-29 2012-10-03 四川蓝星机械有限公司 Method for welding oblique inserted pipe of large chemical equipment
CN105382438A (en) * 2015-12-24 2016-03-09 哈尔滨锅炉厂有限责任公司 Novel oblique-inserted-pipe double-side welding groove and welding method
CN105382438B (en) * 2015-12-24 2017-11-10 哈尔滨锅炉厂有限责任公司 New inclining tube welding by both sides groove and welding method
CN109366089A (en) * 2018-12-30 2019-02-22 中国石油天然气第建设有限公司 It is a kind of quick group of small-bore flange straight pipe to tooling
CN109894636A (en) * 2019-03-19 2019-06-18 兰州兰石重型装备股份有限公司 A kind of method of shape of a saddle pipe connecting flange height in quick determining cone
CN109822199A (en) * 2019-04-22 2019-05-31 晋西工业集团有限责任公司 A kind of process of continuous line welding

Also Published As

Publication number Publication date
CN102390002B (en) 2014-04-09
ZA201300785B (en) 2013-12-23
WO2012129994A1 (en) 2012-10-04
PL227290B1 (en) 2017-11-30
PL403056A1 (en) 2014-01-20

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