CN101683701A - Welding technique of submerged arc welding of mechanical controlled rolling and controlled cooling structural steel - Google Patents
Welding technique of submerged arc welding of mechanical controlled rolling and controlled cooling structural steel Download PDFInfo
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- CN101683701A CN101683701A CN200810223096A CN200810223096A CN101683701A CN 101683701 A CN101683701 A CN 101683701A CN 200810223096 A CN200810223096 A CN 200810223096A CN 200810223096 A CN200810223096 A CN 200810223096A CN 101683701 A CN101683701 A CN 101683701A
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Abstract
The invention relates to a welding technique of submerged arc welding of a mechanical controlled rolling and controlled cooling structural steel, comprises the following steps: preweld preparation procedure of preparation of a groove for the mechanical controlled rolling and controlled cooling structural steel, groove butt assembly and selection of welding materials, back welding procedure, filling welding procedure, cover surface welding procedure, interlayer temperature controlling procedure and postweld cooling procedure, wherein the preweld preparation procedure includes a preweld preheating step and the setting of welding ambient temperature; the preweld preheating step preheats welded parts and the preheating temperature is in direct proportion to the layer thickness of the structural steel; the selected welding materials in the preweld preparation procedure are a low light type submerged arc welding wire and a submerged arc welding agent; the interlayer temperature range is controlled to be higher than the preheating temperature, but lower than 250 DEG C; in the procedures of back welding, filling welding and cover surface welding, the type and the polarity of the welding current are direct current and reversed polarity, the current intensity is 500A to 550A, the welding speed is 400mm/min to 450mm/min, and the heat input quantity is 2.2KJ/mm to 3.0KJ/mm; the cooling procedure adopts air cooling; and the characteristics of high strength and high toughness of TMCP structural steel is guaranteed.
Description
Technical field
The present invention relates to welding procedure, relate in particular to a kind of mechanical controlled rolling and control cooling structure steel welding technique of submerged arc welding.
Background technology
Development and progress of science and technology along with petroleum industry, steel construction develops towards high parameter, maximization direction day by day in the ocean engineering, therefore the steel performance that Welding Structure is used proposes more and more higher requirement, steel itself not only will have good comprehensive mechanical properties, and good welding performance will be arranged.Adopt mechanical controlled rolling and control cooling (TMCP, Thermo-mechanical control process) offshore engineering structure steel that explained hereafter goes out, it has, and obdurability is good, the characteristics of excellent weldability, for the contribution that makes new advances is done in the ocean engineering exploitation.But, this steel are under the Thermal Cycle effect, machinery controlled rolling and control cooling (TMCP) structural steel, its HAZ (heat affected zone, welding heat affected zone) the grain growth phenomenon inevitably takes place in tissue, the characteristics of its high strength, high tenacity are seriously lost, HAZ embrittlement and the ruckbildung even more serious occurred, hindered the application of this structural steel in ocean engineering thus than general normalized steel.
Therefore design is fit to mechanical controlled rolling and the welding procedure of controlling cooling (TMCP) structural steel, and it can be brought into play in ocean engineering should effect, necessary.
Summary of the invention
Main purpose of the present invention is to overcome the above-mentioned shortcoming that existing product exists, and a kind of mechanical controlled rolling is provided and controls cooling structure steel welding technique of submerged arc welding, by selecting suitable welding material for use and setting rational welding parameter, make this structural steel under the thermal cycle effect of welding procedure, crystal grain is stable not to be changed, effectively avoid embrittlement and the ruckbildung of HAZ, with the high strength that guarantees the TMCP structural steel, the characteristics of high tenacity.
The objective of the invention is to realize by following technical scheme.
Controlled rolling of the present invention's machinery and control cooling structure steel welding technique of submerged arc welding, it is characterized in that, comprise to mechanical controlled rolling and control cooling structure steel be equipped with groove, groove dock assemble and the weldering of selected welding material before preparatory process, the bottoming welding sequence, fill welding sequence, the cover welding operation, interlayer temperature control and postwelding refrigerating work procedure; It is characterized in that be provided with the weld preheating step before the described weldering in the preparatory process and set the environment temperature of welding, this weld preheating step is that welding portion is carried out preheating, preheat temperature is directly proportional with the structural steel layer thickness; The welding material of selecting in the preparatory process before the described weldering comprises low light-duty welding wire for submerged-arc welding and low light-duty submerged arc welding flux; The scope of described control interlayer temperature is less than 250 ℃ greater than preheat temperature; Described bottoming welding sequence, fill that welding current type and polarity are dc reverse connection in welding sequence and the cover welding operation, current strength is 500 to 550A, and speed of welding is 400 to 450mm/min, and hot input quantity is 2.2 to 3.0kJ/mm; Adopt the air cooling mode to cool off in the described refrigerating work procedure, cooling velocity is controlled at 0.1 to 30 ℃/S scope.
Aforesaid mechanical controlled rolling and control cooling structure steel welding technique of submerged arc welding, the welding portion of wherein weld preheating step preheating comprise welding district and the scope of 70mm to 80mm on every side thereof, and pre-heating mean adopts roasting preheating or resistive heating device preheating.
Aforesaid mechanical controlled rolling and control cooling structure steel welding technique of submerged arc welding, the environment temperature of wherein setting welding is greater than-20 ℃.
Aforesaid mechanical controlled rolling and control cooling structure steel welding technique of submerged arc welding, wherein low light-duty welding wire for submerged-arc welding diameter is φ 4.0mm or φ 2.4mm.
Aforesaid mechanical controlled rolling and control cooling structure steel welding technique of submerged arc welding, wherein Zhi Bei groove is single face V font groove or two-sided V font groove, and bevel angle is 60 ± 5 to spend, and the gap is 0 to 1mm, and root face is 4 to 6mm.
Controlled rolling of the present invention's machinery and the beneficial effect of controlling cooling structure steel welding technique of submerged arc welding, it is by selecting suitable welding material for use and setting rational welding parameter, make this structural steel under the thermal cycle effect of welding procedure, crystal grain is stable not to be changed, effectively avoid embrittlement and the ruckbildung of HAZ, guarantee the high strength of TMCP structural steel, the characteristics of high tenacity.
The specific embodiment
Controlled rolling of the present invention's machinery and control cooling structure steel welding technique of submerged arc welding, it comprise to mechanical controlled rolling and control cooling structure steel be equipped with groove, groove dock assemble and the weldering of selected welding material before preparatory process, the bottoming welding sequence, fill welding sequence, the cover welding operation, interlayer temperature control and postwelding refrigerating work procedure; Its improvements are, are provided with the weld preheating step before this weldering in the preparatory process and set the environment temperature of welding, and this weld preheating step is that welding portion is carried out preheating, and preheat temperature is directly proportional with the structural steel layer thickness; The welding material of selecting in the preparatory process before this weldering comprises low light-duty welding wire for submerged-arc welding and low light-duty submerged arc welding flux; The scope of this control interlayer temperature is less than 250 ℃ greater than preheat temperature; This bottoming welding sequence, fill that welding current type and polarity are dc reverse connection in welding sequence and the cover welding operation, current strength is 500 to 550A, and speed of welding is 400 to 450mm/min, and hot input quantity is 2.2 to 3.0KJ/mm; Adopt the air cooling mode to cool off in this refrigerating work procedure, cooling velocity is controlled at 0.1 to 30 ℃/S scope.
Controlled rolling of the present invention's machinery and control cooling structure steel welding technique of submerged arc welding, wherein, the welding portion of described weld preheating step preheating comprises welding district and the scope of 70mm to 80mm on every side thereof, and pre-heating mean adopts roasting preheating or resistive heating device preheating; The environment temperature of described setting welding is greater than-20 ℃; Described low light-duty welding wire for submerged-arc welding diameter is φ 4.0mm or φ 2.4mm; The groove of described preparation is single face V font groove or two-sided V font groove, and bevel angle is 60 ± 5 degree, and the gap is 0 to 1mm, and root face is 4 to 6mm.
Embodiment:
1, mother metal of Shi Yonging and welding position.
The mother metal trade mark is: D36, D36-Z35, E36, E36-Z35, F36; Operative norm: GB712-2000; Material supply of material state is: the TMCP explained hereafter; Welding position: downhand welding (1G).
2, the selection of welding material.
According to the chemical composition and the mechanical performance matching principle of mother metal and welding material, the low hydrogen type welding wire for submerged-arc welding that uses bright and beautiful safe company to produce: the trade mark is JW-1, model: EH14 meets standard A WS A5.17; The low hydrogen type flux that Jinzhou wlding factory provides: the trade mark is SJ101, and model: F7A6-EH14 meets standard A WSA5.17;
3, the control of preheat temperature, interlayer temperature.
Weld preheating is carried out preheating to the welding portion that welds district and 75mm scope on every side thereof, adopts roasting to carry out preheating, calculates the relation of preheat temperature and thickness of slab according to AWS D1.1 steel construction welding conditions:
Thickness of slab and preheat temperature relation table
| Thickness of slab environment temperature | ≥0℃ | ????＜0℃ |
| ??T≤38 | Minimum preheat temperature: 10 ℃ | Minimum preheat temperature: 21 ℃ |
| ??38＜T≤65 | Minimum preheat temperature: 66 ℃ | Minimum preheat temperature: 66 ℃ |
| ??T＞65 | Minimum preheat temperature: 110 ℃ | Minimum preheat temperature: 110 ℃ |
When environment temperature is lower than-20 ℃, not weld, interlayer temperature is set in 150 ℃.
4, the design of groove type.
1. prepare groove, prepare two-sided V font groove with plasma method, bevel angle is 60 degree, and narrow gap welding connects, and the gap is 0.5mm, and root face is 4mm; Groove and internal and external walls both sides are cleared up, until exposing metallic luster;
2. butt joint assembling groove is checked and is confirmed by zero defect in the 20mm scope at weldering position and edge thereof.
5, the welding condition design is as shown in the table:
6, postwelding cooling.
The type of cooling is an air cooling, and cooling velocity is controlled at 0.1 to 30 ℃/S scope.
7, the detection of welding quality.
By tension test: tensile sample breaks at the mother metal zone, yield strength is 416MPa, tensile strength is 540MPa, is 490MPa greater than material SMYS 355MPa, minimum tensile strength such as D36 among the GB712-2000 (State Standard of the People's Republic of China-hull structural steel standard) all.Illustrate and adopt controlled rolling of the present invention's machinery and control cooling structure steel welding technique of submerged arc welding, can guarantee that mother metal and weld seam (not fracture) keep intensity level preferably.
Impact toughness test by the summer ratio: test temperature is-20 ℃, according to the GB712-2000 standard, satisfies the low-temperature impact temperature value that mother metal is suitable for.Through axis of a weld, the Charpy-type test at several positions, heat affected area records following result of the test.Result of the test shows that minimum is 144J, minimum acceptance value 27J greater than regulation among the AWS D1.1 (AWS-steel construction welding conditions D1.1), illustrate and adopt controlled rolling of the present invention's machinery and control cooling structure steel welding technique of submerged arc welding, can make weld metal and heat affected area obtain good impact flexibility.
D36-Z35 TMCP steel submerged-arc welding machinery performance test result
The controlled rolling of the present invention's machinery and effect and the advantage of controlling cooling structure steel welding technique of submerged arc welding:
The machinery controlled rolling is at carbon drop, does not improve under the condition of alloying element content with control cooling structure steel (being called for short the TMCP steel), adopts multicomponent microalloying and controlled rolling and controlled cooling technology crystal grain thinning by a relatively large margin to improve the obdurability of steel.The TMCP structural steel has been represented the developing direction of Aldecor.So-called controlled rolling is that the rolling mill practice that cools off after deformation temperature, drafts (deformation quantity), deformation passage, deformation intermittently staying time, finishing temperature and the finish to gauge of hot-rolled steel is controlled on a kind of quantitative preset program ground.This rolling mill practice is obtaining the best crystal grain thinning and the second mutually equally distributed structural state, thereby the performance of improving steel effectively is a basic goal.Controlled rolling is with common rolling different; its main difference is that controlled rolling not only makes steel reach the shape and size of defined by hot-working; and the crystallite dimension of the abundant refinement steel of working hardening by steel and improve tissue, handle the combination property that just can reach after (Normalizing) so that obtain common normalizing.Controlled rolling is actually the heat treated a kind of subform of high temperature deformation.
The TMCP structural steel is designed into structural state and low grade of steel structural alloy steel has than big-difference from composition, the present invention furthers investigate through the tissue and the performance variation law of heat affected area, welding back controlled rolling and controlled cooling TMCP structural steel, find the TMCP structural steel, its intensity is not subject matter, the embrittlement of coarse grain zone is the focus that needs concern, simultaneously, because the welding coarse grain zone is in the zone of transition of weld seam and mother metal, it not only has tangible physics and chemical inhomogeneities, but also often form stress and concentrate because of geometry inhomogeneities such as undercut and crackle appear in toe of weld and root of weld place, thereby the welding coarse grain zone is a weak link in the whole welding joints, for this reason, according to the welding technique of submerged arc welding of AWS D1.1 steel construction welding conditions design the present invention to the TMCP structural steel, the optimal control of this welding condition makes TMCP structural steel weld seam and heat affected area obtain the favorable tissue performance.
The mechanical controlled rolling of the present invention's design is by the rational welding parameter designing with control cooling structure steel welding technique of submerged arc welding, reasonably groove type design, reasonably welding material is selected, final TMCP structural steel weld seam and the heat affected area of guaranteeing obtains the favorable tissue performance, is applied to the requirement that ocean steel construction is built thereby can meet.
The rational welding parameter is to guarantee that weld seam and heat affected area obtain the essential condition of good organization's performance.The wlding that the present invention uses is selected according to mother metal among the AWS D1.1 (AWS-steel construction welding conditions D1.1) and wlding equal strength matching principle, the welding wire for submerged-arc welding solder flux trade mark is JW-1/SJ101, belong to low hydrogen type wlding (diffusion H content is less than 8ml/100g), this wlding can make weld metal possess stronger resistance hydrogen induced cracking ability, and weld metal and heat affected area can obtain good fracture toughness.The sweating heat input can not be too small, too smallly can not fully guarantee the abundant penetration of groove, there are defectives such as incomplete fusion, slag inclusion, the excessive weld metal peak temperature that then can cause of sweating heat input is too high, thereby the cooling back forms thick martensitic structure of hardening, therefore the serious fracture toughness that reduces weld seam and heat affected area selects moderate sweating heat input to seem particularly important, and heat input range of choice is among the present invention: 2.3 to 2.9KJ/mm.In addition, reasonably weld preheating also is the key factor that guarantees welding quality with interlayer temperature control: described corresponding various preheat temperature of different thicknesss of slab and interlayer temperature among the present invention.Cold crack is a kind of major defect that may occur in the welding process, and it is that postwelding is cooled to generation under the lower temperature.For the TMCP steel, greatly about martensite begin near the transition temperature Ms point or more the low temperature interval be easy to produce cold crack.Studies show that, hydrogen content and distribution thereof in the tendency of hardenability of steel, the welding point, and the stress state of welding point is the three big principal elements that produce cold crack in TMCP steel when welding.Because welding heat affected zone has bigger tendency of hardenability and notch effect, thereby cold crack mainly occurs in the heat affected area of TMCP steel.Preheating is the effective ways that prevent cold crack in the structural steel welding procedure, and it is by prolonging t cool time
8/5, can improve weld metal zone hydrogen diffusion velocity, promote the effusion of hydrogen, thereby have the dehydrogenation effect.Can also pass through to reduce the postwelding cooling velocity simultaneously, thereby produce the weld seam microscopic structure lower crack sensitivity.Also can control the caused welding of internal stress that heat expansion and shrinkage produce in the welding process by preheating shrinks and distortion.
The size of interlayer temperature influences the peak temperature and the cooling velocity of welding bead, and the excessive lower floor's welding bead grain structure that directly causes of interlayer temperature is thick, and welding seam tissue capability worsens; Interlayer temperature is low excessively to cause the too fast formation hardened structure of cooling velocity, thus the present invention design weld interpass temperature can not be less than preheat temperature and must not be greater than 250 ℃.
The above, it only is preferred embodiment of the present invention, be not that the present invention is done any pro forma restriction, every foundation technical spirit of the present invention all still belongs in the scope of technical solution of the present invention any simple modification, equivalent variations and modification that above embodiment did.
Claims (5)
1, a kind of mechanical controlled rolling and control cooling structure steel welding technique of submerged arc welding, it is characterized in that, comprise to mechanical controlled rolling and control cooling structure steel be equipped with groove, groove dock assemble and the weldering of selected welding material before preparatory process, the bottoming welding sequence, fill welding sequence, the cover welding operation, interlayer temperature control and postwelding refrigerating work procedure; It is characterized in that be provided with the weld preheating step before the described weldering in the preparatory process and set the environment temperature of welding, this weld preheating step is that welding portion is carried out preheating, preheat temperature is directly proportional with the structural steel layer thickness; The welding material of selecting in the preparatory process before the described weldering comprises low light-duty welding wire for submerged-arc welding and low light-duty submerged arc welding flux; The scope of described control interlayer temperature is less than 250 ℃ greater than preheat temperature; Described bottoming welding sequence, fill that welding current type and polarity are dc reverse connection in welding sequence and the cover welding operation, current strength is 500 to 550A, and speed of welding is 400 to 450mm/min, and hot input quantity is 2.2 to 3.0KJ/mm; Adopt the air cooling mode to cool off in the described refrigerating work procedure, cooling velocity is controlled at 0.1-30 ℃/S scope.
2, mechanical controlled rolling according to claim 1 and control cooling structure steel welding technique of submerged arc welding, it is characterized in that, the welding portion of described weld preheating step preheating comprises welding district and the scope of 70mm to 80mm on every side thereof, and pre-heating mean adopts roasting preheating or resistive heating device preheating.
3, mechanical controlled rolling according to claim 1 and control cooling structure steel welding technique of submerged arc welding is characterized in that the environment temperature of described setting welding is greater than-20 ℃.
4, mechanical controlled rolling according to claim 1 and control cooling structure steel welding technique of submerged arc welding is characterized in that described low light-duty welding wire for submerged-arc welding diameter is φ 4.0mm or φ 2.4mm.
5, mechanical controlled rolling according to claim 1 and control cooling structure steel welding technique of submerged arc welding, it is characterized in that the groove of described preparation is single face V font groove or two-sided V font groove, bevel angle is 60 ± 5 degree, the gap is 0 to 1mm, and root face is 4 to 6mm.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102198565A (en) * | 2011-04-08 | 2011-09-28 | 胜利油田龙玺石油钢管有限公司 | Novel dissimilar steel welding technology |
| CN102632328A (en) * | 2012-04-24 | 2012-08-15 | 武桥重工集团股份有限公司 | Low-temperature submerged-arc automatic welding method for Q370qE steel |
| CN103406644A (en) * | 2013-08-20 | 2013-11-27 | 中国海洋石油总公司 | Submerged-arc welding process for longitudinal seam and circular seam welding of pipe sections |
| CN104308338A (en) * | 2014-09-15 | 2015-01-28 | 安徽鸿路钢结构(集团)股份有限公司 | Submerged-arc welding process for steel |
| CN105364276A (en) * | 2015-10-31 | 2016-03-02 | 江苏振光电力设备制造有限公司 | Welding machining technology of high-strength-steel steel pipe tower |
| CN109719367A (en) * | 2019-02-25 | 2019-05-07 | 苏州华达环保设备股份有限公司 | The longitudinal seam welding method of wind-power tower |
| CN112705867A (en) * | 2019-10-24 | 2021-04-27 | 青岛九合重工机械有限公司 | Method for welding T-shaped joint of pump truck |
| CN113714608A (en) * | 2021-09-09 | 2021-11-30 | 重庆大学 | Submerged-arc welding method for high-strength hybrid steel cross joint |
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2008
- 2008-09-27 CN CN200810223096A patent/CN101683701A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102198565A (en) * | 2011-04-08 | 2011-09-28 | 胜利油田龙玺石油钢管有限公司 | Novel dissimilar steel welding technology |
| CN102632328A (en) * | 2012-04-24 | 2012-08-15 | 武桥重工集团股份有限公司 | Low-temperature submerged-arc automatic welding method for Q370qE steel |
| CN103406644A (en) * | 2013-08-20 | 2013-11-27 | 中国海洋石油总公司 | Submerged-arc welding process for longitudinal seam and circular seam welding of pipe sections |
| CN104308338A (en) * | 2014-09-15 | 2015-01-28 | 安徽鸿路钢结构(集团)股份有限公司 | Submerged-arc welding process for steel |
| CN105364276A (en) * | 2015-10-31 | 2016-03-02 | 江苏振光电力设备制造有限公司 | Welding machining technology of high-strength-steel steel pipe tower |
| CN109719367A (en) * | 2019-02-25 | 2019-05-07 | 苏州华达环保设备股份有限公司 | The longitudinal seam welding method of wind-power tower |
| CN112705867A (en) * | 2019-10-24 | 2021-04-27 | 青岛九合重工机械有限公司 | Method for welding T-shaped joint of pump truck |
| CN113714608A (en) * | 2021-09-09 | 2021-11-30 | 重庆大学 | Submerged-arc welding method for high-strength hybrid steel cross joint |
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Open date: 20100331 |