CN105755239A - Method for improving low-temperature impact toughness of large-diameter large-wall-thickness high-strength hot-bent pipe - Google Patents
Method for improving low-temperature impact toughness of large-diameter large-wall-thickness high-strength hot-bent pipe Download PDFInfo
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- CN105755239A CN105755239A CN201410785220.XA CN201410785220A CN105755239A CN 105755239 A CN105755239 A CN 105755239A CN 201410785220 A CN201410785220 A CN 201410785220A CN 105755239 A CN105755239 A CN 105755239A
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Abstract
The invention provides a method for improving the low-temperature impact toughness of a large-diameter large-wall-thickness high-strength hot-bent pipe. According to the method, a longitudinal-seam submerged-arc-welded pipe is adopted as a mother pipe, and is subjected to hot bending through medium-frequency induction heating with the frequency in a range of 700-1000 Hz to produce the large-diameter large-wall-thickness high-strength hot-bent pipe. Chemical components of a weld seam of the longitudinal-seam submerged-arc-welded pipe comprise, by mass percentage, 0.35-0.65% of Ni. Hot bending is carried out at the heating temperature of 930-1030 DEG C for 1-5 min, then at the spray cooling speed of 3-25 DEG C/s, and then at the tempering temperature of 450-550 DEG C for 30-60 min. The mother pipe has the outer diameter in a range of 1016-1422 mm and the wall thickness of 22-40 mm. The strength of the mother pipe meets the technical requirements of a Russia Wuqia pipe, which is a TY14-156-82-2009 electric welded steel pipe adopted by a main fuel gas pipe with an operating pressure of 11.8 MPa and the diameter of 1420 mm and having the strength at the K65 level.
Description
Technical field
The present invention relates to a kind of method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall.
Background technology
Bend pipe is one of most important parts of long distance oil-gas pipelined.Owing to, in oil-gas transportation process, increasingly complex stress is often born at these positions, to its performance requirement it is also proposed that higher requirement.With the exploitation of polar region petroleum resources, low temperature (-40 DEG C) performance requirement of feed-line is also more and more higher.The heavy caliber of oil-gas transportation, heavy wall high-strength low temperature bend pipe mainly adopts the curved method of ERW fire bending to produce.ERW bends in process in fire bending, although weld seam is on the indeformable neutral conductor, it does not have the effect of deformation, but weld seam is also the same with body, it is necessary to experience the process of a heating, water-spraying control, tempering.In this course, there is significant change in the tissue of weld seam, thus causing that significant change occurs performance.To high tensile pipeline steel pipe, for guaranteeing the impact flexibility of weld seam, it is common to adopt Mn-Mo-Ti-B series solder wire, increase the content of intragranular acicular ferrite by forming the oxide of Ti in weld seam, improve the low-temperature impact toughness of weld seam.Different from ERW, the wall thickness of bend pipe is bigger.Bending the heating in process in fire bending and in cooling water-spraying control process, owing to being subject to the restriction of water-spraying control pressure, its water-spraying control speed is also affected by certain restriction.Further, since the existence of a large amount of nonmetal oxides in weld seam, also reduce the quenching degree of weld seam, make weld seam be readily available pro-eutectoid ferrite, reduce the low-temperature impact toughness of corner bead.And the existence of this oxide, also promote to be formed when high rate of cooling intragranular acicular ferrite and martensite/austenite island that large-size is distributed along ferrite grain boundaries.The tissue of this weld seam dramatically different with hot-bending bends body, makes weld seam organize and body also significantly different with the development law of performance in drawing process.When high tempering, in weld seam, martensite/austenite island is decomposed to form the carbide along ferrite crystal grain distribution, causes that the low-temperature impact toughness of weld seam is low.In conventional bend pipe research, seldom pay close attention to the low-temperature flexibility of weld seam, cause that the low-temperature impact toughness of weld seam is difficult to meet technical requirement in the Development and Production of thick section and high strength low temperature bend pipe.Therefore, low temperature (-40 DEG C) impact flexibility of weld seam becomes the key factor affecting the high-strength hot-bending bends performance of heavy wall.
Summary of the invention
Goal of the invention
It is an object of the invention to provide a kind of method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall.
Summary of the invention
The method of the high-strength hot-bending bends low-temperature impact toughness of described raising heavy caliber thick wall is, adopts the ERW that submerged-arc welding produces to manage as mother, obtains the high-strength hot-bending bends of heavy caliber thick wall through 700～1000Hz curved method of Frequency Induction Heating fire bending,
The chemical composition of described straight welded pipe welding-seam comprises the Ni that mass percent is 0.35%～0.65%,
The curved technological parameter of described fire bending is: heating-up temperature is 930～1030 DEG C, temperature retention time is 1～5min；Water-spraying control speed is 3～25 DEG C/s；Temperature is 450～550 DEG C, temperature retention time is 30～60min,
The external diameter of described female pipe is 1016～1422mm, wall thickness is 22～40mm, intensity meets the technology requirement of Russia's Wuqia pipeline " TY14-156-82-2009 operating pressure is 11.8MPa, diameter be the intensity used by 1420 millimeters of combustion gas main pipelines be the electric welded steel pipe of K65 level ", yield strength >=550MPa, tensile strength >=690MPa.
The frequency of preferred described Frequency Induction Heating is 850～1000Hz.
Preferably, the chemical composition of described straight welded pipe welding-seam also comprises C:0.05%～0.09%, Mn:1.60%～1.75%, Si:0.1%～0.30%, Mo:0.10%～0.30%, Cr:0.001%～0.20%, Cu:0.01%～0.20%, Ti+Nb+V:0.04%～0.09%, all the other are Fe and inevitable impurity, and described percentage ratio is mass percent.Wherein, specifically, the mass percent of Ti, Nb, V can respectively 0.013%～0.016%, 0.028%～0.056%, 0.015%～0.017%.
The described submerged-arc welding method producing female pipe employing is prior art, and concrete technology condition can select according to practical situation, it is possible to directly adopt commercially available satisfactory female pipe.Preferably, described female pipe is the ERW adopting two-sided 4 submerged-arc weldings production of JCOE molding or UOE molding.Described JCOE, UOE forming method is the forming method of known ERW, wherein JCOE molding refers to steel plate order by J type, C type, O type molding, forming method expanding after welding, UOE molding refers to steel plate order by U-shaped, O type molding, forming method expanding after welding.
The present invention according to the wall thickness of described heavy caliber thick wall hot-bending bends, can adjust the Ni content of female pipe weld seam.Preferably, during female thickness of pipe wall≤27mm, the Ni content of straight welded pipe welding-seam is 0.35%～0.45%, more preferably 0.35%～0.40%；During female thickness of pipe wall >=27mm, the Ni content of straight welded pipe welding-seam is 0.45%～0.65%, more preferably 0.56%～0.62%.
The production method of described heavy caliber thick wall hot-bending bends can adjust, according to the Ni content of female pipe weld seam, the technological parameter that fire bending is curved.Preferably, when the Ni content of described straight welded pipe welding-seam is 0.35%～0.45%, fire bending bending process parameter is: heating-up temperature is 930～990 DEG C, temperature retention time is 1～5min；Water-spraying control speed is 10～25 DEG C/s；Temperature is 480～550 DEG C, insulation 30～60min, and preferred fire bending bending process parameter is: heating-up temperature is 930～990 DEG C, fltting speed is 10～25mm/min, temperature retention time is 2～3min；Water-spraying control speed is 10～20 DEG C/s；Temperature is 480～550 DEG C, insulation 35～45min；When the Ni content of described straight welded pipe welding-seam is 0.45%～0.65%, fire bending bending process parameter is: heating-up temperature is 930～1030 DEG C, temperature retention time is 1～5min；Water-spraying control speed is 3～15 DEG C/s；Temperature is 480～550 DEG C, insulation 30～60min, and preferred fire bending bending process parameter is: heating-up temperature is 930～1030 DEG C, fltting speed is 10～20mm/min, temperature retention time is 2～3min；Water-spraying control speed is 3～15 DEG C/s；Temperature is 480～550 DEG C, insulation 30～40min.
The present invention combines the production technology of actual hot-bending bends, the composition of different wall mother's pipe weld seam is proposed reasonable request, control by technological parameters such as the curved heating-up temperature of fire bending, rate of cooling and temperatures, improve the low-temperature impact toughness of heavy wall hot-bending bends weld seam, low-temperature impact work can be made to reach the technology requirement of high-strength low temperature bend pipe, and namely-40 DEG C of summers reach than low-temperature impact work: three sample monodrome >=50J；Meansigma methods >=60J.
The present invention compared with prior art has the advantage that 1, only passes through add appropriate Ni in weld seam and be namely remarkably improved the low-temperature impact toughness of thick-wall bend weld seam in conjunction with fire bending bending process；2, bend pipe integrated artistic can be conducive to control according to the content of different wall thickness control Ni.
Detailed description of the invention
" K65 ERW " described in following comparative example and embodiment, refer to that its intensity meets the technology requirement of Russia's Wuqia pipeline " TY14-156-82-2009 operating pressure is 11.8MPa, diameter be the intensity used by 1420 millimeters of combustion gas main pipelines be the electric welded steel pipe of K65 level ", yield strength >=550MPa, tensile strength >=690MPa.
Comparative example 1
It is 22mm, external diameter is the bend pipe of 1219mm that this comparative example prepares wall thickness.Female pipe of bend pipe is the K65 ERW being adopted two-sided 4 submerged-arc weldings of JCOE molding to produce by Julong Steel Pipe Co., Ltd, wall thickness is 22mm, external diameter is 1219mm, chemical composition (the mass percent of its weld seam, %) it is: C:0.08%, Mn:1.65%, Si:0.20%, Ni:0.21%, Mo:0.17%, Cr:0.08%, Cu:0.15%, Ti:0.013%, Nb:0.029%, V:0.017% that all the other are Fe and inevitable impurity.Adopting above-mentioned ERW to carry out hot-bending bends production, fire bending bending process is 900Hz Frequency Induction Heating, and actual heating-up temperature is 930～1030 DEG C, and fltting speed is 10～25mm/min；Actual temperature retention time is 2～3min；Adopting outside water-spraying control, rate of cooling is 10～25 DEG C/s.Carrying out tempering after fire bending kinking bundle in heat-treatment furnace, tempering adopts heats with stove, and temperature is 480～550 DEG C, is incubated 40min after temperature.The summer that sample after different process processes is undertaken-40 DEG C by ASTME23 standard compares low-temperature impact test, low-temperature impact toughness result of the test is as shown in table 1, owing to Ni content is low, the monodrome of its low-temperature impact work and meansigma methods all occur specifying (monodrome >=50J less than standard；Meansigma methods >=60J) situation, it is impossible to meet the requirement of technical standard order.
Low temperature (-40 DEG C) ballistic work of table 122mm bend pipe
Embodiment 1
It is 22mm, external diameter is the bend pipe of 1219mm that the present embodiment prepares wall thickness.Female pipe of bend pipe is the K65 ERW being adopted two-sided 4 submerged-arc weldings of JCOE molding to produce by Julong Steel Pipe Co., Ltd, wall thickness is 22mm, external diameter is 1219mm, chemical composition (the mass percent of its weld seam, %) it is: C:0.08%, Mn:1.63%, Si:0.22%, Ni:0.38%, Mo:0.11%, Cr:0.08%, Cu:0.14%, Ti:0.014%, Nb:0.031%, V:0.015% that all the other are Fe and inevitable impurity.Adopting above-mentioned ERW to carry out hot-bending bends production, fire bending bending process is 900Hz Frequency Induction Heating, and actual heating-up temperature is 930～1030 DEG C, and fltting speed is 10～25mm/min；Actual temperature retention time is 2～3min；Adopting outside water-spraying control, rate of cooling is 10～20 DEG C/s.Hot bending carries out tempering after terminating in heat-treatment furnace, and tempering adopts heats with stove, and temperature is 480～550 DEG C, is incubated 40min after temperature.The summer that sample after different process processes is undertaken-40 DEG C by ASTME23 standard compares low-temperature impact test, low-temperature impact toughness result of the test is as shown in table 2, it is visible when heating-up temperature is 930～990 DEG C, the monodrome of its low-temperature impact work reaches more than 71J, meansigma methods reaches more than 79J, and when heating-up temperature is 1030 DEG C, there is 48J in the monodrome of its ballistic work, less than the 50J that standard specifies.Preferred heating-up temperature is 930～990 DEG C.
Low temperature (-40 DEG C) ballistic work of table 222mm bend pipe
Embodiment 2
It is 30.8mm, external diameter is the bend pipe of 1219mm that the present embodiment prepares wall thickness.Female pipe of bend pipe is the K65 ERW being adopted two-sided 4 submerged-arc weldings of JCOE molding to produce by Julong Steel Pipe Co., Ltd, wall thickness 30.8mm, external diameter are 1219mm, chemical composition (the mass percent of its weld seam, %) it is: containing C:0.07%, Mn:1.66%, Si:0.23%, Ni:0.59%, Mo:0.12%, Cr:0.09%, Cu:0.12%, Ti:0.015%, Nb:0.055%, V:0.015% that all the other are Fe and inevitable impurity.Adopting above-mentioned ERW to carry out hot-bending bends production, fire bending bending process is 950Hz Frequency Induction Heating, and actual heating-up temperature is 930～1030 DEG C, and fltting speed is 10～20mm/min；Actual temperature retention time is 2～3min；Adopting outside water-spraying control, rate of cooling is 3～15 DEG C/s.Carrying out tempering after fire bending kinking bundle in heat-treatment furnace, tempering adopts heats with stove, and temperature is 480～550 DEG C, is incubated 30～40min after temperature.Sample after different process processes carries out the summer of-40 DEG C than low-temperature impact test by ASTME23 standard, and low-temperature impact toughness result of the test is as shown in table 3, it is seen that the monodrome of its low-temperature impact work reaches more than 79J, and meansigma methods reaches more than 92J.
Low temperature (-40 DEG C) ballistic work of table 330.8mm bend pipe
Claims (8)
1. the method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall, it is characterised in that adopt the ERW that submerged-arc welding produces to manage as mother, obtain the high-strength hot-bending bends of heavy caliber thick wall through 700～1000Hz curved method of Frequency Induction Heating fire bending,
The chemical composition of described straight welded pipe welding-seam comprises the Ni that mass percent is 0.35%～0.65%,
The curved technological parameter of described fire bending is: heating-up temperature is 930～1030 DEG C, temperature retention time is 1～5min；Water-spraying control speed is 3～25 DEG C/s；Temperature is 450～550 DEG C, temperature retention time is 30～60min,
The external diameter of described female pipe is 1016～1422mm, wall thickness is 22～40mm, intensity meets the technology requirement of Russia's Wuqia pipeline " TY14-156-82-2009 operating pressure is 11.8MPa, diameter be the intensity used by 1420 millimeters of combustion gas main pipelines be the electric welded steel pipe of K65 level ", yield strength >=550MPa, tensile strength >=690MPa.
2. the method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall as claimed in claim 1, it is characterized in that, the chemical composition of described straight welded pipe welding-seam also comprises C:0.05%～0.09%, Mn:1.60%～1.75%, Si:0.1%～0.30%, Mo:0.10%～0.30%, Cr:0.001%～0.20%, Cu:0.01%～0.20%, Ti+Nb+V:0.04%～0.09%, all the other are Fe and inevitable impurity, and described percentage ratio is mass percent.
3. the method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall as claimed in claim 1 or 2, it is characterised in that described female pipe is the steel pipes with straight adopting two-sided 4 submerged-arc weldings to produce of JCOE molding or UOE molding.
4. the method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall as according to any one of claims 1 to 3 the, it is characterised in that during wall thickness≤27mm of female pipe, the Ni content of straight welded pipe welding-seam is 0.35%～0.45%；During wall thickness >=the 27mm of female pipe, the Ni content of straight welded pipe welding-seam is 0.45%～0.65%.
5. the as claimed in claim 4 method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall the, it is characterised in that during wall thickness≤27mm of female pipe, the Ni content of straight welded pipe welding-seam is 0.35%～0.40%；During wall thickness >=the 27mm of female pipe, the Ni content of straight welded pipe welding-seam is 0.56%～0.62%.
6. the method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall as according to any one of Claims 1 to 5, it is characterised in that
When the Ni content of described straight welded pipe welding-seam is 0.35%～0.45%, fire bending bending process parameter is: heating-up temperature is 930～990 DEG C, temperature retention time is 1～5min；Water-spraying control speed is 10～25 DEG C/s；Temperature is 480～550 DEG C, insulation 30～60min；
When the Ni content of described straight welded pipe welding-seam is 0.45%～0.65%, fire bending bending process parameter is: heating-up temperature is 930～1030 DEG C, temperature retention time is 1～5min；Water-spraying control speed is 3～15 DEG C/s；Temperature is 480～550 DEG C, insulation 30～60min.
7. the method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall as claimed in claim 6, it is characterised in that
When the Ni content of described straight welded pipe welding-seam is 0.35%～0.45%, fire bending bending process parameter is: heating-up temperature is 930～990 DEG C, fltting speed is 10～25mm/min, temperature retention time is 2～3min；Water-spraying control speed is 10～20 DEG C/s；Temperature is 480～550 DEG C, insulation 35～45min；
When the Ni content of described straight welded pipe welding-seam is 0.45%～0.65%, fire bending bending process parameter is: heating-up temperature is 930～1030 DEG C, fltting speed is 10～20mm/min, temperature retention time is 2～3min；Water-spraying control speed is 3～15 DEG C/s；Temperature is 480～550 DEG C, insulation 30～40min.
8. the method improving the high-strength hot-bending bends low-temperature impact toughness of heavy caliber thick wall as according to any one of Claims 1 to 5, it is characterized in that, the high-strength hot-bending bends of described heavy caliber thick wall carries out-40 DEG C of Charpy-type tests, single impact value >=50J, three sample mean >=60J.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107724191A (en) * | 2016-08-12 | 2018-02-23 | 中国铁建重工集团有限公司 | Manufacture method and its obtained elastic clip for the elastic clip of Line for Passenger Transportation track switch |
| CN107775280A (en) * | 2016-08-29 | 2018-03-09 | 中国石油天然气集团公司 | A kind of manufacture method of N08825 nickel-base alloys composite-curve |
| CN108637603A (en) * | 2018-05-12 | 2018-10-12 | 首钢集团有限公司 | A method of improving X70 hot-bending bends welding point low-temperature impact toughness |
| CN114871699A (en) * | 2022-05-26 | 2022-08-09 | 中南大学 | High-strength-toughness X70 pipeline steel elbow with welding joint |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101205593A (en) * | 2007-12-10 | 2008-06-25 | 华北石油管理局第一机械厂 | X80 steel bend pipe and bending technique thereof |
| CN102127697A (en) * | 2011-02-22 | 2011-07-20 | 中国石油天然气集团公司 | Production method of X70 steel grade elbow pipes and pipe fittings |
| CN102189158A (en) * | 2011-03-23 | 2011-09-21 | 河北宇鹏重工管道装备制造有限公司 | Process for bending X100 steel grade large-caliber bent pipe through intermediate frequency induction heating |
| CN102268612A (en) * | 2011-08-25 | 2011-12-07 | 中国石油集团渤海石油装备制造有限公司 | X80 steel elbow with low temperature resistance and manufacturing process thereof |
-
2014
- 2014-12-17 CN CN201410785220.XA patent/CN105755239B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101205593A (en) * | 2007-12-10 | 2008-06-25 | 华北石油管理局第一机械厂 | X80 steel bend pipe and bending technique thereof |
| CN102127697A (en) * | 2011-02-22 | 2011-07-20 | 中国石油天然气集团公司 | Production method of X70 steel grade elbow pipes and pipe fittings |
| CN102189158A (en) * | 2011-03-23 | 2011-09-21 | 河北宇鹏重工管道装备制造有限公司 | Process for bending X100 steel grade large-caliber bent pipe through intermediate frequency induction heating |
| CN102268612A (en) * | 2011-08-25 | 2011-12-07 | 中国石油集团渤海石油装备制造有限公司 | X80 steel elbow with low temperature resistance and manufacturing process thereof |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107724191A (en) * | 2016-08-12 | 2018-02-23 | 中国铁建重工集团有限公司 | Manufacture method and its obtained elastic clip for the elastic clip of Line for Passenger Transportation track switch |
| CN107724191B (en) * | 2016-08-12 | 2024-02-20 | 中国铁建重工集团有限公司 | Manufacturing method of elastic clamp for turnout of passenger special line and elastic clamp manufactured by same |
| CN107775280A (en) * | 2016-08-29 | 2018-03-09 | 中国石油天然气集团公司 | A kind of manufacture method of N08825 nickel-base alloys composite-curve |
| CN107775280B (en) * | 2016-08-29 | 2019-06-11 | 中国石油天然气集团公司 | A kind of manufacturing method of N08825 nickel-base alloy composite-curve |
| CN108637603A (en) * | 2018-05-12 | 2018-10-12 | 首钢集团有限公司 | A method of improving X70 hot-bending bends welding point low-temperature impact toughness |
| CN114871699A (en) * | 2022-05-26 | 2022-08-09 | 中南大学 | High-strength-toughness X70 pipeline steel elbow with welding joint |
| CN114871699B (en) * | 2022-05-26 | 2023-11-24 | 中南大学 | High-strength and high-toughness X70 pipeline steel bent pipe with welded joint |
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