CN100450689C - Repairing welding method for crack of rotor support power generator - Google Patents
Repairing welding method for crack of rotor support power generator Download PDFInfo
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- CN100450689C CN100450689C CNB2006100216340A CN200610021634A CN100450689C CN 100450689 C CN100450689 C CN 100450689C CN B2006100216340 A CNB2006100216340 A CN B2006100216340A CN 200610021634 A CN200610021634 A CN 200610021634A CN 100450689 C CN100450689 C CN 100450689C
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Abstract
The repair welding process for rotor spider of water turbine generator includes the following steps: 1. preparing welding material and selecting welding bevel; 2. welding through pre-heating the workpiece in a annealing furnace to 100-150 deg.c, symmetrical welding by several workers, further heating to about 240 deg.c, higher than the preheating temperature, and dehydrogenating treatment after welding; and 3. inspection on the welding seam after the workpiece is cooled to room temperature. The present invention has the advantages of less welding stress and less welding deformation.
Description
Technical field
The present invention relates to a kind of repair method of low temperature crackle, particularly repairing welding method for crack of rotor support power generator.
Background technology
The low temperature crackle is that postwelding is cooled near the martensite point Ms crack that produces under the 200-300 ℃ of temperature.This type of crackle is cooled to uniform temperature sometimes and occurs immediately, will pass through several hours, several days even just produce after incubation period for more time sometimes.The appearance of these characteristics and rotor field spider yoke ring crackle coincide.Because the heat affected area at nearly weld seam cracks, and illustrates that the plasticity of weld metal or mother metal is lower, constraint (restraint) degree is higher.This and workpiece are extremely thick, and the stress distribution of blank ectonexine welding means very uneven and that present factory adopts have direct relation during moulding.Therefore, the key of the technological measure reprocessed of rotor field spider yoke ring crackle is to seek the countermeasure that prevents cold crack.
Summary of the invention
Purpose of the present invention promptly is to overcome the shortcoming of prior art, provides a kind of welding stress little, and deflection is controlled at the repairing welding method for crack of rotor support power generator in the specification requirement scope, has solved the difficult problem of large-scale weld assembly crackle repair welding.
Purpose of the present invention is achieved through the following technical solutions: repairing welding method for crack of rotor support power generator, and it may further comprise the steps:
(1) prepares before the weldering
The control of a, welding material: select hydrogen controlled electrode, welding rod is dried before use, must use heat-preservation cylinder when receiving;
The selection of b, bevel for welding: repair welding position employing carbon arc air gouging is dug groove, and dig, weld along trapezoidal two waist multilayers, multiple tracks during repair welding to falling the trapezoid cross section; After finishing, repair welding immediately it is hung in annealing furnace, whole heating, stress relief annealing;
Before the groove gouge, the integrally annealed of rotor field spider elder generation, and utilize the thorough removal of defects of annealing waste heat, clean out impurity in each 30-50mm scope of groove and both sides thereof behind the gouge, until exposing metallic luster, 100% magnetic powder inspection is carried out in groove and the both sides thereof cleared up.Detect a flaw and to weld after qualified;
(2) welding
A, before workpiece welding, whole workpiece hung in to hang out after annealing furnace integral body is preheated to 100 ℃-150 ℃ welds;
B, welding is undertaken by many people's while symmetries, the bottoming of Φ 3.2 welding rods, Φ 4 welding rod repair weldings, dc reverse connection is adopted in welding, the welding method of little heat input, little electric current, short arc, string(er) bead, multi-pass welding, and the drawing effect that utilizes the back welding bead is so that grain refinement, all weld seams all should continuous welding, the interlayer joint staggers more than the 50mm, after each layer welding finishes, all want thoroughly scarfing cinder rapidly, and clean with wire brush, and answer the scrutiny weld seam, confirm that zero defect can the repair welding second layer, by this requirement, completely until weldering, and the big rejected region of first repair welding, back repair welding rejected region is little; In the welding process, every weldering one deck uses air pressure gun hammering weld seam, and weld seam is extended, and reduces welding interior stress, crystal grain thinning;
C, for the welding of thick weld seam, along with increasing of the weld seam number of plies, temperature should corresponding rising between the road, is greater than preheat temperature, is controlled at about 240 ℃;
D, the postwelding hydrogen that disappears is handled, and the postwelding hydrogen that should disappear is immediately handled, and whole workpiece is hung in annealing furnace integral body be heated to about 300-350 ℃, insulation 2h, slow cooling in annealing furnace then;
(3) postwelding check: work-piece cools is carried out visual examination to the repair welding weld seam to room temperature, do not allow welding point that defectives such as obvious undercut are arranged, weld seam and mother metal transition slyness, and polishing back butt welded seam carries out ultrasonic examination.
By top narration as can be seen, the present invention has the following advantages: welding stress is little, and deflection is controlled in the specification requirement scope, satisfied the requirement of drawing fully, guarantee carrying out smoothly of production, obtained good economic benefit, solved the difficult problem of large-scale weld assembly crackle repair welding.
The specific embodiment
The present invention will be further described below in conjunction with the power station generator rotor field spider crackle repair welding of east, Lip river, and east, Lip river power station generator rotor field spider forms 40.35 tons of net weight by yoke ring, centerbody, last plectane, following plectane, disk and three kinds of gusset assembly weldings.Wherein yoke ring is a large-scale steel-casting by the design drawing requirement, its external diameter is φ 3941mm, internal diameter φ 3621mm, height 2060mm, wall thickness 160mm, weigh 27.921 tons, because of its weight is big, general foundry enterprise is difficult to the Integratively casting and finishes this workpiece, and the gradation casting then is easy to generate various casting flaws and casting long processing time, the cost height can not satisfy production requirement.After change the rotor field spider yoke ring into large-scale weld assembly after consulting, material adopts 16Mn.
The making of east, Lip river power station generator rotor field spider yoke ring is adopted: be welded into yoke ring again behind the shaping of segmentation cold coiling, the school circle.Because workpiece reaches 160mm, the stress distribution of blank ectonexine very uneven (internal layer is a compression, and skin is a tension) during moulding, the butt weld force-bearing situation is very abominable.Finally, welding subsidiary factory be assembled into rotor field spider when welding yoke ring find to produce the large-scale crackle in 7 places.In order to guarantee product quality and process-cycle, must in time reprocess processing to workpiece.The crackle characteristic analysis: from appearance, crack orientation is parallel with weld seam, belongs to longitudinal crack; Crack surfaces non-oxidation color illustrates that crackle forms at a lower temperature.From producing on the zone, crackle is positioned at the heat affected area; And the crackle near weld seam is tiny, and when the heat affected area direction developed, crackle was expanded gradually.Therefore, in sum, can judge this crackle is the low temperature crackle.
Handling cold crack mainly sets about from following three aspects: select the low welding material of crack sensitivity for use; Reduce local hydrogen content and reduce local stress.
A. reduce local hydrogen content, this can adopt a series of measures to realize, adopts the low hydrogen type welding method, selects the low hydrogen type welding material for use; Welding material cures before weldering and gives drying, and keeps properly; Temperature, the humidity of reprocessing environment are controlled; Weld preheating;
B. control cooling velocity, the congenital composition that depends on mother metal and welding material of the hardened structure of welding point, but can control by Thermal Cycle and cooling velocity thereof the day after tomorrow.Rationally the control cooling velocity is to obtain the crack resistance tissue, prevents the effective measures of cold crack;
C. preheating, preheating are the very effective measures that prevent welding cold cracking.Because it can directly prolong cool time, improve the heat affected area tissue, eliminate or the remaining diffusible hydrogen content of minimizing welding point, reduce the weldment thermograde, reduce thermal stress, thereby alleviate constraint stress.Generally, preheat temperature can adopt carbon equivalent method or cold crack sensitiveness index method to calculate;
D. after heat, the effect of after heat are further to carry out dehydrogenation, continue the preheating role.The temperature of after heat should be suitable for the rapid diffusion of hydrogen, escapes in a large number, and generally from 150 ℃ of beginnings to 300 ℃, the diffusion velocity of hydrogen is quite rapid, therefore gets 300 ℃-350 ℃ usually;
E. reduce and eliminate constraint stress, the major measure that reduces constraint stress is to select the little groove type of constraint stress; Adopt the little welding procedure of successively dwindling groove of constraint stress; Avoid the heat undue concentration, control suitable interlayer temperature and postwelding hammering etc., wherein the most important thing is the choose reasonable slope type.Repairing welding method for crack of rotor support power generator, it may further comprise the steps:
(1) prepares before the weldering
The control of a, welding material
Because constraint stress height when workpiece is reprocessed for improving the crack resistance of weld seam, is selected hydrogen controlled electrode.Rotor field spider yoke ring material is 16Mn, belongs to 35kg/cm
2The level low alloy high-strength steel, the principle that is complementary according to weld strength and mother metal in order to improve crack resistance, guarantees that weld metal has enough intensity, good plasticity and toughness, selects to use the J507 welding rod of alkaline low-hydrogen type during welding.
Welding rod before use on request bake out temperature and time dry, prevent that too high bake out temperature from making coating embrittlement or low excessively bake out temperature not reach drying effect.Require the welder must use heat-preservation cylinder when receiving, welding rod must be dried after taking out from insulating box and surpassing 4h again.
The selection of b, bevel for welding
According to analysis, formulate when reprocessing the repair welding measure, must solve mother metal in manufacturing process because its cold-working stress is big, the critical problem that causes welding very easily to crack, otherwise the generation once more that can't essence solves the repair welding bead crack.
The repair welding position being adopted carbon arc air gouging plane groove for this reason, and dig to falling the trapezoid cross section, along trapezoidal two waist multilayers, multiple tracks welding, is open owing to the repair welding position like this during repair welding.Weld seam is drawn close to the center gradually along trapezoidal two waists, shrinks to both sides along trapezoidal two waists during contraction, because the weld seam of two waists does not connect together as yet, can shrink to both sides separately, has avoided contained excessive, causes the weld seam drawing crack.
When two side welds when the center connects together because continuous sequence, constantly weld both sides, heat constantly replenishes, and already the both sides mother metal is heated to certain scope, has avoided the chilling contraction.After finishing, repair welding immediately it is hung in annealing furnace in addition, whole heating, and stress relief annealing, it is big so just to have solved the mother metal constraint stress, causes the problem of bead crack.
Before the groove gouge, the integrally annealed of rotor field spider elder generation produces cold-working stress to eliminate when weld stress and yoke ring cold coiling are shaped, and prevents that crackle from extending aggravation when gouge, and utilizes the thorough removal of defects of annealing waste heat.Clean out impurity in each 30-50mm scope of groove and both sides thereof behind the gouge, until exposing metallic luster.100% magnetic powder inspection is carried out in groove and the both sides thereof cleared up.Detect a flaw and to weld after qualified.
(2) welding
A, in view of workpiece size big, wall thickness, heat radiation is exceedingly fast.Adopt common oxy-acetylene preheating, because heating can't evenly be carried out, heat distribution is inhomogeneous, causes new stress riser on the contrary easily.Therefore, before workpiece welding, whole workpiece hung in to hang out after annealing furnace integral body is preheated to 100 ℃-150 ℃ weld.
B, welding are undertaken by several welders' while symmetries.The bottoming of Φ 3.2 welding rods, Φ 4 welding rod repair weldings.Dc reverse connection is adopted in welding, the welding method of little heat input, little electric current, short arc, string(er) bead, multi-pass welding, so that it is overheated to reduce to greatest extent, and the drawing effect that utilizes the back welding bead is so that grain refinement, and all weld seams all should continuous welding, the interlayer joint staggers more than the 50mm, after each layer welding finishes, all want thoroughly scarfing cinder rapidly, and clean with wire brush.And answer the scrutiny weld seam, confirm that zero defect can the repair welding second layer, by this requirement, completely until weldering.And the big rejected region of first repair welding, back repair welding rejected region is little.In the welding process, every weldering one deck uses air pressure gun hammering weld seam, makes weld seam obtain extending, and reduces welding interior stress, crystal grain thinning.Hammering should keep even appropriateness, avoids hammering excessive, to prevent to produce new crackle.
C, for the welding of thick weld seam, for effectively preventing welding cold cracking and eliminate residual stress that temperature controlling is very important between the road.Falling in the weld seam of trapezoidal groove, the closer to the surface, the content of Mn is just high more, and the phenomenon of accumulation is arranged.So along with increasing of the weld seam number of plies, temperature is answered corresponding rising between the road, is greater than preheat temperature, is controlled at about 240 ℃.
D, the postwelding hydrogen that disappears is handled, and in order effectively to remove diffusible hydrogen and the part residual stress in the weld seam, the postwelding hydrogen that disappears is immediately handled.For this reason, whole workpiece is hung in annealing furnace integral body be heated to about 300-350, insulation 2h, slow cooling in annealing furnace then.
(3) postwelding check
Work-piece cools is carried out visual examination to the repair welding weld seam to room temperature, do not allow welding point that defectives such as obvious undercut are arranged, weld seam and mother metal transition slyness.Polishing back butt welded seam carries out ultrasonic examination.After testing, it is qualified fully to detect a flaw, and repair welding is achieved success.
Claims (2)
1, repairing welding method for crack of rotor support power generator is characterized in that: it may further comprise the steps:
(1) prepares before the weldering
The control of a, welding material: select hydrogen controlled electrode, welding rod is dried before use, must use heat-preservation cylinder when receiving;
The selection of b, bevel for welding: repair welding position employing carbon arc air gouging is dug groove, and dig, weld along trapezoidal two waist multilayers, multiple tracks during repair welding to falling the trapezoid cross section; After finishing, repair welding immediately it is hung in annealing furnace, whole heating, stress relief annealing;
Before the groove gouge, the integrally annealed of rotor field spider elder generation, and the thorough removal of defects of utilization annealing waste heat, clean out impurity in each 30-50mm scope of groove and both sides thereof behind the gouge, until exposing metallic luster, 100% magnetic powder inspection is carried out in groove and the both sides thereof cleared up, detect a flaw and to weld after qualified;
(2) welding
A, before workpiece welding, whole workpiece hung in to hang out after annealing furnace integral body is preheated to 100 ℃-150 ℃ welds;
B, welding is undertaken by many people's while symmetries, the bottoming of Φ 3.2 welding rods, Φ 4 welding rod repair weldings, dc reverse connection is adopted in welding, the welding method of little heat input, little electric current, short arc, string(er) bead, multi-pass welding, and the drawing effect that utilizes the back welding bead is so that grain refinement, all weld seams all should continuous welding, the interlayer joint staggers more than the 50mm, after each layer welding finishes, all want thoroughly scarfing cinder rapidly, and clean with wire brush, and answer the scrutiny weld seam, confirm that zero defect can the repair welding second layer, by this requirement, completely until weldering, and the big rejected region of first repair welding, back repair welding rejected region is little; In the welding process, every weldering one deck uses air pressure gun hammering weld seam;
C, for the welding of thick weld seam, along with increasing of the weld seam number of plies, temperature should corresponding rising between the road, is greater than preheat temperature, is controlled at about 240 ℃;
D, the postwelding hydrogen that disappears is handled, and the postwelding hydrogen that should disappear is immediately handled, and whole workpiece is hung in annealing furnace integral body be heated to about 300-350 ℃, insulation 2h, slow cooling in annealing furnace then;
(3) postwelding check: work-piece cools is carried out visual examination to the repair welding weld seam to room temperature, do not allow welding point that defectives such as obvious undercut are arranged, weld seam and mother metal transition slyness, and polishing back butt welded seam carries out ultrasonic examination.
2, repairing welding method for crack of rotor support power generator according to claim 1 is characterized in that: after welding rod takes out from insulating box and surpasses 4h when preparing before the weldering, must dry again.
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| CNB2006100216340A CN100450689C (en) | 2006-08-23 | 2006-08-23 | Repairing welding method for crack of rotor support power generator |
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| CN102794540A (en) * | 2012-09-03 | 2012-11-28 | 河海大学常州校区 | Welding repair process for crack of container spreader |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000275384A (en) * | 1999-03-24 | 2000-10-06 | Ishikawajima Harima Heavy Ind Co Ltd | Repairing method for reactor pressure vessel |
| CN1294039A (en) * | 2000-11-14 | 2001-05-09 | 青铜峡市特鑫焊接热喷涂有限公司 | Method for controlling weld deformation of blades for axial-flow water turbine |
| EP1287936A1 (en) * | 2001-08-09 | 2003-03-05 | Kabushiki Kaisha Toshiba | Repair method for structure and repair welding apparatus |
| CN1691996A (en) * | 2002-12-02 | 2005-11-02 | 三菱重工业株式会社 | Turbine rotor repair method |
-
2006
- 2006-08-23 CN CNB2006100216340A patent/CN100450689C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000275384A (en) * | 1999-03-24 | 2000-10-06 | Ishikawajima Harima Heavy Ind Co Ltd | Repairing method for reactor pressure vessel |
| CN1294039A (en) * | 2000-11-14 | 2001-05-09 | 青铜峡市特鑫焊接热喷涂有限公司 | Method for controlling weld deformation of blades for axial-flow water turbine |
| EP1287936A1 (en) * | 2001-08-09 | 2003-03-05 | Kabushiki Kaisha Toshiba | Repair method for structure and repair welding apparatus |
| CN1691996A (en) * | 2002-12-02 | 2005-11-02 | 三菱重工业株式会社 | Turbine rotor repair method |
Non-Patent Citations (2)
| Title |
|---|
| 宝钢炼铁厂主排风机叶轮修复. 任克文.江苏冶金，第32卷第5期. 2004 |
| 宝钢炼铁厂主排风机叶轮修复. 任克文.江苏冶金，第32卷第5期. 2004 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102794540A (en) * | 2012-09-03 | 2012-11-28 | 河海大学常州校区 | Welding repair process for crack of container spreader |
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