CN101104234A - Water wheel generating set cast steel part defect repair welding crackle processing method - Google Patents
Water wheel generating set cast steel part defect repair welding crackle processing method Download PDFInfo
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- CN101104234A CN101104234A CNA200710049718XA CN200710049718A CN101104234A CN 101104234 A CN101104234 A CN 101104234A CN A200710049718X A CNA200710049718X A CN A200710049718XA CN 200710049718 A CN200710049718 A CN 200710049718A CN 101104234 A CN101104234 A CN 101104234A
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Abstract
The invention discloses a processing method for repairing the defect of welding cracks of cast steel parts of a hydroelectric generating set, comprising procedures of clearing the defect, pre-heating, welding and post-welding heat processing. The procedure of clearing the defect adopts a mechanical processing method that oil pollution and impurities are cleared after the defect is confirmed not to exist by coloring. In the pre-heating procedure, the pre-heated temperature is 80 to 120 DEG C. The welding procedure adopts welding of plural layers and directions; line energy is 20 to 40 KJ per cm; the diameter of a welding rod is Phi 4, current is 170A, voltage is 24V; welding speed is 0.11 to 0.22 cm per second. The cast steel parts can swing transversely with small amplitude in the welding process. In the post-welding heat processing procedure, the welding part to be repaired and the part near the welding part to be repaired for 150mm to200 mm are heated to 300 to 400 DEG C, and the temperature can be kept for two hours. The beneficial effect of the invention is that the invention solves the problem of repairing the welding cracks of large cast steel parts. Evidence shows that companies have repaired the welding of the cast steel parts of power equipment with the invention, and welding cracks have never occurred.
Description
Technical field
The present invention relates to a kind of water wheel generating set cast steel part defect repair welding crackle processing method.
Background technology
Steel-casting accounts for quite heavy ratio in the generating equipment that company produced, the crown of the hydraulic turbine, down ring, web, blade, stator, top cover, base ring etc. and water to send out seat ring, the wheel hub of rotor field spider, the thrust of upper spider in the machine first-class mostly be steel-casting, its material is ZG20SiMn or ZG230-450 normally, characteristics are that size is big, quality heavy, wall thickness, rigidity is strong during welding, constraint (restraint) degree is big, produce very big internal stress during welding, created prerequisite for forming crackle.The carbon equivalent of ZG20SiMn or ZG230-450 is 0.317% to the maximum, and solderability is good in theory, but because steel-casting is smelted segregation, the composition inhomogeneities, formation Local C, S, P element exceed standard, and phosphorus content exceeds standard.As: preheat temperature during welding, heat input, post weld heat treatment is incorrect, and hardened structure will appear in weld seam and heat affected area, and this has just increased generation cold crack trend; Simultaneously, the S element exceeds standard, and forms a large amount of low melting point sulfide and eutectic at intergranular, and phosphorus content exceeds standard has increased austenite quantity in the crystallization process, reduced the solubility of sulphur in solid solution, impel the segregation of sulphur, formed more low melting point sulfide and eutectic, under the effect of internal stress, the HOT CRACK FOR WELDING P defective very easily appears during welding, often occur crackle during repair welding, cause a large amount of durations, manpower, energy consumption, wlding loss and waste, should take measures necessary to solve this difficult problem.
Summary of the invention
The objective of the invention is to a kind of water wheel generating set cast steel part defect repair welding crackle processing method, solve a water wheel generating set cast steel part defect repair welding crackle difficult problem.
The objective of the invention is to be achieved through the following technical solutions: water wheel generating set cast steel part defect repair welding crackle processing method, it comprises removal of defects, preheating, welding and post weld heat treatment step, described removal of defects step adopts machining process, after zero defect is confirmed in dye penetrant inspection, remove greasy dirt impurity; In the described preheating step, preheat temperature is 80-120 ℃; Described welding step adopts multi-pass welding, and heat input is 20-40KJ/cm, core diameter Φ 4, and electric current 170A, voltage 24V, speed of welding is 0.11-0.22cm/s, can do teeter by a small margin in the welding process; Described post weld heat treatment step heating repair welding position and near 150mm-200mm scope are incubated 2 hours to 300-400 ℃.
Described removal of defects step adopts the lonely gouge force method of carbon removal of defects, the carburized layer of must polishing after the carbon arc air gouging removal of defects, and grinding depth is 1.5-2mm, after zero defect is confirmed in dye penetrant inspection, removes greasy dirt impurity.
The intact one deck of every weldering all adopts the air pressure gun vibration in the described welding step.
In the described welding step during repair welding along the welding of two waist multilayer multiple tracks, draw close to the center gradually along repair welding position two waists by weld seam, shrink to both sides along repair welding position two waists during contraction.
In the described welding step, SMAW, hydrogen controlled electrode J507 are adopted in the repair welding of little defective.Big, the dark defective of area adopts SMAW bottoming layer 2-3 earlier, adopts the mixed gas arc welding welding then, and the mist volume ratio is Ar: CO2=8: 2, and welding material ERS0-6.
The invention has the beneficial effects as follows the large-scale steel-casting repair welding crackle problem that solved, company carries out repair welding according to the present invention to the steel-casting of generating equipment product, weld crack never occurs, for company's steel-casting repair welding has accumulated experience.
The specific embodiment
Further describe technical scheme of the present invention below in conjunction with embodiment: water wheel generating set cast steel part defect repair welding crackle processing method is characterized in that it comprises removal of defects, preheating, welding and post weld heat treatment step.
Removal of defects
Defective can adopt the force method of machining or the lonely gouge of carbon to remove, the carburized layer of must polishing after the carbon arc air gouging removal of defects, grinding depth 1.5-2mm, the possibility that cracks when reducing to weld, zero defect is confirmed in dye penetrant inspection, eradicates formation of crack, removes greasy dirt impurity etc.
Welding material and welding method
The repair welding of little defective can be selected SMAW for use; hydrogen controlled electrode J507, big, the dark defective of area can be selected SMAW bottoming layer 2-3 for use, adopts the mixed gas arc welding welding then; the mist volume ratio is Ar: CO2=8: 2, and welding material ERS0-6.
Preheating
The thermograde that produces when preheating can reduce welding reduces welding stress, prevents the generation of crackle.Preheat temperature is subjected to the influence of chemical analysis, wall thickness, environment, general preheating 80--120C, and wall thickness, preheat temperature can be high when environment temperature was low.
Welding
Control line energy in the welding process, heat input too conference produce Wei Shi soma, influence mechanical performance, and heat input is too little, and hardened structure can appear in weld seam and heat affected area, is easy to generate crackle.Proof employing heat input is that 20-40KJ/cm can meet the demands by experiment.If adopt SMAW, core diameter Φ 4, electric current 170A, voltage 24V, then speed of welding is 0.11-0.22cm/s, can do teeter by a small margin in the welding process.Only control welding current well, voltage, speed of welding could effectively be controlled weld heat input well.
Adopt multi-pass welding, multi-pass welding is convenient to the input of control line energy on the one hand, and layer welding bead in back plays drawing effect to the anterior layer weld seam on the other hand, and the energy crystal grain thinning improves the weld seam mechanical performance, improves the toughness and the plasticity of weld seam, reduces the generation of crackle.Interlayer temperature can not be lower than preheat temperature during welding, should reduce welding point when adopting gas shielded arc welding as far as possible, reduces striking and receives the defective that arc produces.
The intact one deck of every weldering all adopts the air pressure gun vibration in the welding process.One power surface vibration can knock out slag, oxide skin, prevents to weld slag inclusion, and vibration can reduce welding interior stress on the other hand, prevents the generation of crackle.Have only to produce plastic deformation and just can reach the purpose of eliminating internal stress, so extent of vibration goes out to go sightseeing bright with weld seam, produce plastic deformation and be advisable.
For large-scale defective, along two waist multilayers, multiple tracks is welded during repair welding, draw close to the center gradually along repair welding position two waists by weld seam, shrink to both sides along repair welding position two waists during contraction, because two waist weld seams do not connect together as yet, can be separately shrink, avoided that constraint (restraint) degree is excessive to cause the weld seam drawing crack to both sides.When two side welds when the center connects together, the weld seam amount significantly reduces, and because continuous sequence early is heated to higher temperature with the both sides mother metal the sixth of the twelve Earthly Branches, has reduced the welding temperature gradient, has reduced welding interior stress, thereby reaches the purpose that prevents that crackle from producing.
Post weld heat treatment
After finishing, welding carries out annealing in process immediately, eliminate stress, improve mechanical performance, annealing in process must carry out after-baking immediately, heating repair welding position and near 150mm-200mm scope are to 300-400 ℃, be incubated 2 hours, help the effusion of diffusible hydrogen and prevent weld seam and hardened structure appears in the heat affected area.
Claims (6)
1. water wheel generating set cast steel part defect repair welding crackle processing method, it is characterized in that it comprises removal of defects, preheating, welding and post weld heat treatment step, described removal of defects step adopts machining process, after zero defect is confirmed in dye penetrant inspection, removes greasy dirt impurity; In the described preheating step, preheat temperature is 80-120 ℃; Described welding step adopts multi-pass welding, and heat input is 20-40KJ/cm, core diameter Φ 4, and electric current 170A, voltage 24V, speed of welding is 0.11-0.22cm/s, can do teeter by a small margin in the welding process; Described post weld heat treatment step heating repair welding position and near 150mm-200mm scope are incubated 2 hours to 300-400 ℃.
2. water wheel generating set cast steel part defect repair welding crackle processing method according to claim 1, it is characterized in that described removal of defects step adopts the lonely gouge force method of carbon removal of defects, necessary polishing carburized layer after the carbon arc air gouging removal of defects, grinding depth is 1.5-2mm, after zero defect is confirmed in dye penetrant inspection, remove greasy dirt impurity.
3. water wheel generating set cast steel part defect repair welding crackle processing method according to claim 1 is characterized in that the intact one deck of every weldering all adopts the air pressure gun vibration in the described welding step.
4. water wheel generating set cast steel part defect repair welding crackle processing method according to claim 1, weld along two waist multilayer multiple tracks when it is characterized in that in the described welding step repair welding, draw close to the center gradually along repair welding position two waists by weld seam, shrink to both sides along repair welding position two waists during contraction.
5. water wheel generating set cast steel part defect repair welding crackle processing method according to claim 1 is characterized in that in the described welding step, and SMAW, hydrogen controlled electrode J507 are adopted in the repair welding of little defective.
6. water wheel generating set cast steel part defect repair welding crackle processing method according to claim 1; it is characterized in that in the described welding step; big, the dark defective of area adopts SMAW bottoming layer 2-3 earlier; adopt the mixed gas arc welding welding then; the mist volume ratio is Ar: CO2=8: 2, and welding material ERS0-6.
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| CNB200710049718XA CN100528465C (en) | 2007-08-10 | 2007-08-10 | Water wheel generating set cast steel part defect repair welding crackle processing method |
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| CN100528465C CN100528465C (en) | 2009-08-19 |
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Cited By (25)
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| CN101954564A (en) * | 2010-11-10 | 2011-01-26 | 河南中孚实业股份有限公司 | Method for repairing main shaft cracks of continuous kneader |
| CN101982287A (en) * | 2010-10-09 | 2011-03-02 | 中广核工程有限公司 | Automatic welding method of nuclear island main pipes |
| CN102009279A (en) * | 2010-12-13 | 2011-04-13 | 中国航空工业集团公司北京航空材料研究院 | Method for lowering crack sensitivity of aeroengine cast stainless steel component during repair welding |
| CN102126062A (en) * | 2011-01-07 | 2011-07-20 | 蓬莱巨涛海洋工程重工有限公司 | Secondary repair process method of high-strength steel welds |
| CN102248262A (en) * | 2011-06-20 | 2011-11-23 | 江门市新会区同达化工机械制造有限公司 | Welding repair process method for cast steel kettle rings of autoclaved kettle and cover edge cracks |
| CN102528220A (en) * | 2011-12-15 | 2012-07-04 | 宁夏共享集团有限责任公司 | Welding method for controlling hardness of weld seam heat-affected zone of low-carbon steel material for casting |
| CN102658417A (en) * | 2012-03-12 | 2012-09-12 | 天津重钢机械装备股份有限公司 | Welding repair technology of casting defect of high-chromium cast iron |
| CN102770227A (en) * | 2011-02-23 | 2012-11-07 | 新日本制铁株式会社 | Manufacturing method for welded joint and welded joint |
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| CN104439704A (en) * | 2014-11-06 | 2015-03-25 | 中国航空工业集团公司北京航空材料研究院 | Laser repair welding method for casting flaws of Ti3Al castings |
| CN105014200A (en) * | 2015-07-31 | 2015-11-04 | 共享铸钢有限公司 | Steel casting loose defect welding method |
| CN105149727A (en) * | 2015-09-24 | 2015-12-16 | 共享铸钢有限公司 | Medium carbon steel defect removal method |
| CN105382432A (en) * | 2014-08-12 | 2016-03-09 | 洛阳九创重型机械有限公司 | Defect mending technology for heavy-duty metal castings |
| CN105537736A (en) * | 2015-12-22 | 2016-05-04 | 渤海船舶重工有限责任公司 | Welding method for boron cast steel of primary shielding structure of nuclear reactor containment |
| CN108127282A (en) * | 2017-12-22 | 2018-06-08 | 沈阳透平机械股份有限公司 | For the rotor main shaft of wind tunnel compressor and the welding method of wheel hub |
| CN108637428A (en) * | 2018-05-18 | 2018-10-12 | 共享铸钢有限公司 | A kind of high intensity gear ring class cast steel part defect weldering repair renovation method |
| CN109531043A (en) * | 2018-11-28 | 2019-03-29 | 徐州徐工矿山机械有限公司 | A kind of repair method for sealing structure penetrating crack |
| CN110303297A (en) * | 2019-07-02 | 2019-10-08 | 浙江开诚机械有限公司 | CrMoV steel-casting reprocesses repair method |
| CN110340619A (en) * | 2019-07-17 | 2019-10-18 | 攀钢集团钛业有限责任公司 | Stainless steel bell crack restorative procedure |
| CN110405319A (en) * | 2019-08-15 | 2019-11-05 | 江苏京成机械制造有限公司 | The process for welding repair of heat resisting cast steel ZG40Cr24Ni9Si2NRe |
| CN113199203A (en) * | 2021-04-29 | 2021-08-03 | 共享铸钢有限公司 | Method for repairing defects of steel castings |
| CN114453825A (en) * | 2022-01-27 | 2022-05-10 | 安徽应流铸业有限公司 | Welding repair method for defects of low-alloy high-strength steel casting |
| CN114850621A (en) * | 2022-06-13 | 2022-08-05 | 张炜 | Method for welding oil stain welding part |
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- 2007-08-10 CN CNB200710049718XA patent/CN100528465C/en not_active Expired - Fee Related
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| CN101982287B (en) * | 2010-10-09 | 2011-09-28 | 中广核工程有限公司 | Automatic welding method of nuclear island main pipes |
| CN101954564A (en) * | 2010-11-10 | 2011-01-26 | 河南中孚实业股份有限公司 | Method for repairing main shaft cracks of continuous kneader |
| CN101954564B (en) * | 2010-11-10 | 2013-04-24 | 河南中孚实业股份有限公司 | Method for repairing main shaft cracks of continuous kneader |
| CN102009279A (en) * | 2010-12-13 | 2011-04-13 | 中国航空工业集团公司北京航空材料研究院 | Method for lowering crack sensitivity of aeroengine cast stainless steel component during repair welding |
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| CN105382432A (en) * | 2014-08-12 | 2016-03-09 | 洛阳九创重型机械有限公司 | Defect mending technology for heavy-duty metal castings |
| CN104191066A (en) * | 2014-09-01 | 2014-12-10 | 江苏政田重工股份有限公司 | Cast steel repair welding process |
| CN104439704A (en) * | 2014-11-06 | 2015-03-25 | 中国航空工业集团公司北京航空材料研究院 | Laser repair welding method for casting flaws of Ti3Al castings |
| CN105014200A (en) * | 2015-07-31 | 2015-11-04 | 共享铸钢有限公司 | Steel casting loose defect welding method |
| CN105149727B (en) * | 2015-09-24 | 2017-11-28 | 共享铸钢有限公司 | A kind of medium carbon steel casting defect minimizing technology |
| CN105149727A (en) * | 2015-09-24 | 2015-12-16 | 共享铸钢有限公司 | Medium carbon steel defect removal method |
| CN105537736A (en) * | 2015-12-22 | 2016-05-04 | 渤海船舶重工有限责任公司 | Welding method for boron cast steel of primary shielding structure of nuclear reactor containment |
| CN108127282A (en) * | 2017-12-22 | 2018-06-08 | 沈阳透平机械股份有限公司 | For the rotor main shaft of wind tunnel compressor and the welding method of wheel hub |
| CN108637428B (en) * | 2018-05-18 | 2020-10-27 | 共享铸钢有限公司 | Repair welding repair repairing method for defects of high-strength gear ring type steel castings |
| CN108637428A (en) * | 2018-05-18 | 2018-10-12 | 共享铸钢有限公司 | A kind of high intensity gear ring class cast steel part defect weldering repair renovation method |
| CN109531043A (en) * | 2018-11-28 | 2019-03-29 | 徐州徐工矿山机械有限公司 | A kind of repair method for sealing structure penetrating crack |
| CN110303297A (en) * | 2019-07-02 | 2019-10-08 | 浙江开诚机械有限公司 | CrMoV steel-casting reprocesses repair method |
| CN110340619A (en) * | 2019-07-17 | 2019-10-18 | 攀钢集团钛业有限责任公司 | Stainless steel bell crack restorative procedure |
| CN110405319A (en) * | 2019-08-15 | 2019-11-05 | 江苏京成机械制造有限公司 | The process for welding repair of heat resisting cast steel ZG40Cr24Ni9Si2NRe |
| CN113199203A (en) * | 2021-04-29 | 2021-08-03 | 共享铸钢有限公司 | Method for repairing defects of steel castings |
| CN114453825A (en) * | 2022-01-27 | 2022-05-10 | 安徽应流铸业有限公司 | Welding repair method for defects of low-alloy high-strength steel casting |
| CN114850621A (en) * | 2022-06-13 | 2022-08-05 | 张炜 | Method for welding oil stain welding part |
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| CN100528465C (en) | 2009-08-19 |
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