CN107420049A - A kind of full titanium alloy drilling rod of friction welding type - Google Patents

A kind of full titanium alloy drilling rod of friction welding type Download PDF

Info

Publication number
CN107420049A
CN107420049A CN201710818069.9A CN201710818069A CN107420049A CN 107420049 A CN107420049 A CN 107420049A CN 201710818069 A CN201710818069 A CN 201710818069A CN 107420049 A CN107420049 A CN 107420049A
Authority
CN
China
Prior art keywords
titanium alloy
friction
drilling rod
rod
joint
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201710818069.9A
Other languages
Chinese (zh)
Inventor
陈长青
王显林
纪海涛
王青林
姜荣凯
徐斌
孔令楠
李竹滨
李齐富
左斌
支鹏鹏
马伟华
张泽龙
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BOHAI NENGKE DRILL PIPE Co Ltd
CNPC Bohai Equipment Manufacturing Co Ltd
Original Assignee
BOHAI NENGKE DRILL PIPE Co Ltd
CNPC Bohai Equipment Manufacturing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BOHAI NENGKE DRILL PIPE Co Ltd, CNPC Bohai Equipment Manufacturing Co Ltd filed Critical BOHAI NENGKE DRILL PIPE Co Ltd
Priority to CN201710818069.9A priority Critical patent/CN107420049A/en
Publication of CN107420049A publication Critical patent/CN107420049A/en
Pending legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21BEARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • 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
    • B23K20/00Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/12Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by friction; Friction welding

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)

Abstract

The invention discloses a kind of full titanium alloy drilling rod of friction welding type, belongs to drill pipe art, including the body of rod prepared using titanium alloy, in addition to the joint prepared using titanium alloy, is welded between the body of rod and joint using friction welding method.It is contemplated that reducing drilling rod overall weight, avoid tool joint from producing displacement and bending stress with drilling rod body linkage section, improve connective stability, reduce stress concentration, lift the fatigue life of drilling rod.

Description

A kind of full titanium alloy drilling rod of friction welding type
Technical field
The invention belongs to drill pipe art, is to be related to a kind of full titanium alloy drilling rod of friction welding type more specifically.
Background technology
With modern petroleum industrial expansion, oil/gas drilling proposes higher and higher requirement to drilling technology, particularly The drilling well of some special process, some conventional drilling tool, equipment can not meet the requirement of drilling well.It is special to meet both at home and abroad The drilling well requirement of different process well, develops a series of drilling tool and equipment, wherein titanium alloy drilling rod is exactly to develop in recent years The new varieties got up.Titanium alloy drilling rod with the steel drill rod of routine compared to having bigger flexibility, with structural stress it is small, The characteristics of endurance, corrosion-resistant and light weight, in high corrosion well, super short radial horizontal well, have in deep-well, ultra-deep well drilling application Good adaptability.
External titanium alloy drilling rod uses conventional steel tool joint material, and the connection of drilling rod body and tool joint is to use The mode of cold setting connects.Because drilling rod body is titanium alloy, and titanium alloy tool joint is using steel alloy, titanium alloy with The difference of the modulus of elasticity of steel alloy can cause tool joint to produce relative displacement with drilling rod body linkage section, in this can Great bending stress is produced, so as to cause tool joint and the fatigue life of drilling rod body junction to be greatly reduced.
The content of the invention
It is an object of the invention to provide a kind of full titanium alloy drilling rod of friction welding type, it is intended to drilling rod overall weight is reduced, Avoid tool joint from producing displacement and bending stress with drilling rod body linkage section, improve connective stability, reduce stress concentration, carry Rise the fatigue life of drilling rod.
In order to solve the above technical problems, the technical solution used in the present invention is:
A kind of full titanium alloy drilling rod of friction welding type, including the body of rod prepared using titanium alloy, in addition to prepared using titanium alloy Joint, between the body of rod and joint using friction welding method weld.
Preferably, the friction welding method is 1), pre-welding treatment;2), initial friction;3), secondary friction;4), push up Section processing.
Preferably, the pre-welding treatment, including the connection end to the connecting end surface of the body of rod of drilling rod and the joint of drilling rod Face is machined, and carries out bevel processing, then by the connecting end surface of the body of rod and the connecting end surface of the joint Docking.
Preferably, the groove is the single bevel groove with root face, and it is opened on the joint connecting end surface, institute It is 1~2mm to state root face, and the angle of the groove is 30 °~45 °.
Preferably, the initial friction, including initial friction pressure is set as 45~50 kN, the initial friction time is 1.5~2 s, initial friction rotating speed are 530~560 rpm.
Preferably, the secondary friction, including secondary friction pressure is set as 100~110 kN, secondary fraction time It is set as 18~20 s, secondary friction rotating speed 530~560 rpm.
Preferably, the top section processing, including upsetting force is set as 430~450kN, upset time is 16~18s.
It is using beneficial effect caused by above-mentioned technical proposal:With the steel joint and the titanium alloy body of rod of prior art The drilling rod produced by cold working mode is compared, and the present invention passes through friction welding (FW) using the body of rod and joint that are titanium alloy material The method of connecing is welded, successively by pre-welding treatment, initial friction, it is secondary friction and top section processing etc. step, this titanium alloy Drilling rod is full titanium alloy, compared to the drilling rod that conventional steel joint adds the titanium alloy body of rod, titanium alloy tool joint corrosion resistance is strong, Good toughness, nonmagnetic, fatigue life is long and density is small, mitigates drilling rod overall weight;Drilling rod is changed using friction-welding technique The connected mode of joint and the body of rod, cold setting mode, friction welding can only be used compared to conventional steel joint and the titanium alloy body of rod The body of rod and joint connective stability can be lifted, reduces junction stress concentration, titanium alloy drilling rod fatigue life is lifted, passes through essence True state modulator, Quick Oxidation under titanium alloy high-temperature is effectively prevented, intensity that joint is connected with the body of rod and stably is significantly increased Property, ensure that the full titanium alloy drilling rod overall performance of friction welding type is excellent.
Brief description of the drawings
Fig. 1 is the structural representation of one embodiment of the invention;
Fig. 2 is the structural representation of the groove of the body of rod and joint in Fig. 1;
Each figure number is entitled:The welding position of 1-joint, 2-body of rod and joint, 3-body of rod, a-bevel angle, B-root face.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, below in conjunction with the accompanying drawings and embodiment pair The present invention is described in further detail.It should be appreciated that specific embodiment described herein is used only for explaining the present invention, and It is not used in the restriction present invention.
It should be noted that when element is referred to as " being fixed on " or " being arranged at " another element, it can be directly another On one element or it is connected on another element.When an element is known as " being connected to " another element, it can To be directly to another element or be indirectly connected on another element.
It is to be appreciated that term " length ", " width ", " on ", " under ", "front", "rear", "left", "right", " vertical ", The orientation or position relationship of the instruction such as " level ", " top ", " bottom " " interior ", " outer " are to be closed based on orientation shown in the drawings or position System, it is for only for ease of and describes the present invention and simplify description, rather than indicates or imply that signified device or element must have Specific orientation, with specific azimuth configuration and operation, therefore be not considered as limiting the invention.
In addition, term " first ", " second " are only used for describing purpose, and it is not intended that instruction or hint relative importance Or the implicit quantity for indicating indicated technical characteristic.Thus, define " first ", the feature of " second " can be expressed or Implicitly include one or more this feature.In the description of the invention, " multiple " are meant that two or more, Unless otherwise specifically defined.
Refer to shown in Fig. 1, the present invention includes the body of rod 3 prepared using titanium alloy, in addition to prepared using titanium alloy Joint 1, welded between the body of rod 3 and joint 1 using friction welding method.
The drilling rod of above-mentioned design, its joint 1 also use identical titanium alloy material, can not only reduce the single heavy of drilling rod Amount, and the difference of titanium alloy and alloyed steel elastic modulus can be avoided to cause tool joint 1 to be produced with the linkage section of drill rod body 3 Relative displacement, so as to avoid that great bending stress can be produced in this, so as to which tool joint 1 and drilling rod bar be substantially improved The fatigue life of the junction of body 3, titanium alloy tool joint corrosion resistance is strong, good toughness, nonmagnetic and density are small.
Specifically, the outside dimension at the middle part of the above-mentioned body of rod 3 is 73mm, wall thickness 9.17mm, the body of rod 3 docks with joint At both ends, the external diameter of the body of rod 3 transits to 76.2mm, and wall thickness increases to 19.05mm;It is corresponding, the outside dimension of the connection end of joint 1 For 76.2mm, internal diameter size 38.1mm.
Further, as a kind of a kind of specific embodiment party of the full titanium alloy drilling rod of friction welding type provided by the invention Formula, the friction welding method are 1), pre-welding treatment;2), initial friction;3), secondary friction;4) section processing, is pushed up.
Specifically, as a kind of a kind of embodiment of the full titanium alloy drilling rod of friction welding type provided by the invention, The pre-welding treatment, including the connecting end surface of the connecting end surface of the body of rod 3 of drilling rod and the joint 1 of drilling rod is machined, And bevel processing is carried out, then the connecting end surface of the body of rod 3 is docked with the connecting end surface of the joint 1;The groove For the single bevel groove with root face, and it is opened on the connecting end surface of joint 1, the root face B is 1~2mm, the groove Angle a be 30 °~45 °.
To ensure that the drill pipe friction of titanium alloy connects quality, need the end of the body of rod 3 and joint 1 welding footpath position before welding and Row machining, ensure that solder side inside/outside diameter size is identical, can completely attach to during welding, the solder side of the body of rod 3 is in plane State, the welding end surface of joint 1 take the form of inclined plane state(As shown in Figure 2), above-mentioned groove design, can be realized in friction welding process The end face of the body of rod 3 and the solder side of joint 1 come into contact with, and realize progressively heating fusion, ensure the distribution of welding position metal streamline Uniformly, the weld strength of the joint 1 of drilling rod and the junction of the body of rod 3 of drilling rod is lifted.
Specifically, as a kind of a kind of embodiment of the full titanium alloy drilling rod of friction welding type provided by the invention, The initial friction, including set initial friction pressure as 45~50 kN, initial friction time are 1.5~2 s, initial friction Rotating speed is 530~560 rpm;
In the initial friction stage, as friction pressure increases to initial friction pressure value, the titanium alloy surface for welding contact is rubbed Destroy, the body of rod 3 and the clean metal of joint 1 contact with each other, and burnoff length gradually increases, frictional contact surface surface temperature also with Rise, titanium alloy intensity is declined slightly, and plasticity and toughness step up, and these factors promote coefficient of friction to increase, and friction adds Hot merit improves rapidly, and as contact surface temperature height is to 1100~1200 DEG C, the speed of mainshaft and heating power reach stationary value, this Individual stage titanium alloy surface had both be combined with each other under high-temp plastic state, and was cut by the rotary torsion square of main shaft, and mutually oozed Thoroughly, contact good plasticity titanium alloy and be full of rubbing surface, be allowed to completely isolated with air, prevent the quick oxygen of titanium alloy rubbing surface Change.
Specifically, as a kind of a kind of embodiment of the full titanium alloy drilling rod of friction welding type provided by the invention, The secondary friction, including set secondary friction pressure as 100~110 kN, secondary fraction time are set as 18~20 s, two Secondary friction rotating speed 530~560 rpm.
Secondary friction phase is the Main Stage of titanium alloy friction heating process, and this stage frictional surface temperature is kept for 1200 DEG C Left and right, the bonding phenomenon of titanium alloy material are reduced, and the enhancing of molecular action phenomenon, rubbing surface starts to deform, in the axle of friction torque Under being acted on to pressure, wrought titanium alloy layer is extruded into overlap from friction surface and constantly increased.
Specifically, as a kind of a kind of embodiment of the full titanium alloy drilling rod of friction welding type provided by the invention, The top section processing, including upsetting force is set as 430~450kN, upset time is 16~18s.
Upset processing stage main shaft quickly stops the rotation, and upset force rises to upsetting force value, while the titanium of high temperature deformation Alloy is largely extruded, and overlap quickly increases, and is obtained predetermined deflection by accurate control time and upset force, is made contact surface Oxidative tissue, impurity extruded completely, to ensure to obtain good welding quality.
The above method, tool joint 1 and the connected mode of the body of rod 3 are changed using friction-welding technique, by accurately joining Numerical control system, Quick Oxidation under titanium alloy high-temperature is effectively prevented, the strength and stability that joint 1 is connected with the body of rod 3 is significantly increased, protected The card full titanium alloy drilling rod overall performance of friction welding type is excellent, and friction welding can lift the stabilization that the body of rod 3 is connected with joint 1 Property, reduce junction stress concentration, lift titanium alloy drilling rod fatigue life.
Further, as a kind of a kind of specific embodiment party of the full titanium alloy drilling rod of friction welding type provided by the invention Formula, it is 6~7mm to control friction amount of contraction.
Above-mentioned design, welding zone heat affected area width in titanium alloy mill welding process, effectively lifting weldering can be effectively controlled Area's mechanical performance..
Further, as a kind of complete a kind of embodiment of titanium alloy drilling rod of friction welding type provided by the invention, It is 8~16mm to control welding contracted quantity.
Above-mentioned design, the welding gross shrinkage of whole friction welding process is controlled, oxidative tissue, the oil of contact surface can be made Dirty, dust is extruded completely, to ensure to obtain good welding quality..
Specific case used herein is set forth to the principle and embodiment of the present invention, and above example is said It is bright to be only intended to help the method and its core concept for understanding the present invention.It should be pointed out that the ordinary skill for the art For personnel, under the premise without departing from the principles of the invention, some improvement and modification, these improvement can also be carried out to the present invention Also fallen into modification in the protection domain of the claims in the present invention.

Claims (7)

1. a kind of full titanium alloy drilling rod of friction welding type, including the body of rod prepared using titanium alloy(3), it is characterised in that:Also wrap Include the joint prepared using titanium alloy(1), the body of rod(3)With joint(1)Between using friction welding method weld.
A kind of 2. full titanium alloy drilling rod of friction welding type according to claim 1, it is characterised in that:The friction welding side Method is 1), pre-welding treatment;2), initial friction;3), secondary friction;4) section processing, is pushed up.
A kind of 3. full titanium alloy drilling rod of friction welding type according to claim 2, it is characterised in that:The pre-welding treatment, Including the body of rod to drilling rod(3)Connecting end surface and drilling rod joint(1)Connecting end surface be machined, and carry out out slope Mouth processing, then by the body of rod(3)Connecting end surface and the joint(1)Connecting end surface docking.
A kind of 4. full titanium alloy drilling rod of friction welding type according to claim 3, it is characterised in that:The groove is with blunt The single bevel groove on side, and it is opened in the joint(1)On connecting end surface, the root face is 1~2mm, the angle of the groove For 30 °~45 °.
A kind of 5. full titanium alloy drilling rod of friction welding type according to claim 2, it is characterised in that:The initial friction, Including setting initial friction pressure as 45~50 kN, the initial friction time is 1.5~2 s, and initial friction rotating speed is 530~560 rpm。
A kind of 6. full titanium alloy drilling rod of friction welding type according to claim 2, it is characterised in that:The secondary friction, Including setting secondary friction pressure as 100~110 kN, secondary fraction time is set as 18~20 s, secondary friction rotating speed 530 ~560 rpm.
A kind of 7. full titanium alloy drilling rod of friction welding type according to claim 2, it is characterised in that:The top section processing, Including setting upsetting force as 430~450kN, upset time is 16~18s.
CN201710818069.9A 2017-09-12 2017-09-12 A kind of full titanium alloy drilling rod of friction welding type Pending CN107420049A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710818069.9A CN107420049A (en) 2017-09-12 2017-09-12 A kind of full titanium alloy drilling rod of friction welding type

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710818069.9A CN107420049A (en) 2017-09-12 2017-09-12 A kind of full titanium alloy drilling rod of friction welding type

Publications (1)

Publication Number Publication Date
CN107420049A true CN107420049A (en) 2017-12-01

Family

ID=60432032

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710818069.9A Pending CN107420049A (en) 2017-09-12 2017-09-12 A kind of full titanium alloy drilling rod of friction welding type

Country Status (1)

Country Link
CN (1) CN107420049A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109899004A (en) * 2019-03-12 2019-06-18 淮北林光钻探机电工程有限公司 A kind of exploration casing and its manufacturing method
CN114160956A (en) * 2021-10-29 2022-03-11 苏州思萃熔接技术研究所有限公司 Friction welding method for butt joint of high-strength steel thick-wall pipe and joint
US20230130962A1 (en) * 2021-10-22 2023-04-27 Halliburton Energy Services, Inc. Processing route to design and manufacture highly configurable non-magnetic down-hole sensor collars
US11717911B1 (en) * 2020-10-22 2023-08-08 Paul Po Cheng Method of fusing metal objects together

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1357426A (en) * 2000-12-08 2002-07-10 富士乌兹克斯株式会社 Friction welding process of jointing different metal material
CN101699021A (en) * 2009-11-09 2010-04-28 山西环界石油钻具制造有限公司 Friction welding type kelly bar
CN102211248A (en) * 2011-05-05 2011-10-12 衡阳鸿锦石油钻具有限公司 Oil drill rod connector, drill rod, inertia friction welding process and jig
CN102267005A (en) * 2011-06-27 2011-12-07 江苏融泰石油科技股份有限公司 Friction welding method for welding type extra-heavy drill rod
WO2014152842A2 (en) * 2013-03-14 2014-09-25 David Riggs Methods and apparatuses for subsea flowline and riser pipes with friction welded connectors
EP2489754B1 (en) * 2011-02-18 2016-04-27 Mitsubishi Materials Corporation Hollow drilling steel rod and method of manufacturing the same
CN106312440A (en) * 2015-06-24 2017-01-11 钱立群 Friction welding repair method for hollow steel drill rod
CN107350618A (en) * 2017-06-26 2017-11-17 天津钢管集团股份有限公司 A kind of friction welding method of high-strength tenacity titanium alloy drilling rod material

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1357426A (en) * 2000-12-08 2002-07-10 富士乌兹克斯株式会社 Friction welding process of jointing different metal material
CN101699021A (en) * 2009-11-09 2010-04-28 山西环界石油钻具制造有限公司 Friction welding type kelly bar
EP2489754B1 (en) * 2011-02-18 2016-04-27 Mitsubishi Materials Corporation Hollow drilling steel rod and method of manufacturing the same
CN102211248A (en) * 2011-05-05 2011-10-12 衡阳鸿锦石油钻具有限公司 Oil drill rod connector, drill rod, inertia friction welding process and jig
CN102267005A (en) * 2011-06-27 2011-12-07 江苏融泰石油科技股份有限公司 Friction welding method for welding type extra-heavy drill rod
WO2014152842A2 (en) * 2013-03-14 2014-09-25 David Riggs Methods and apparatuses for subsea flowline and riser pipes with friction welded connectors
CN106312440A (en) * 2015-06-24 2017-01-11 钱立群 Friction welding repair method for hollow steel drill rod
CN107350618A (en) * 2017-06-26 2017-11-17 天津钢管集团股份有限公司 A kind of friction welding method of high-strength tenacity titanium alloy drilling rod material

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
吴夏炎: "中国跨入全钛合金钻杆生产时代", 《中国石油报》 *
张柯柯: "《特种先进连接方法》", 31 August 2016, 哈尔滨工业大学出版社 *
袁文义: "国外钛合金钻杆的研究进展", 《新疆石油科技》 *
赵金: "高性能钻杆研究进展", 《石油矿场机械》 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109899004A (en) * 2019-03-12 2019-06-18 淮北林光钻探机电工程有限公司 A kind of exploration casing and its manufacturing method
US11717911B1 (en) * 2020-10-22 2023-08-08 Paul Po Cheng Method of fusing metal objects together
US20230130962A1 (en) * 2021-10-22 2023-04-27 Halliburton Energy Services, Inc. Processing route to design and manufacture highly configurable non-magnetic down-hole sensor collars
US11654506B2 (en) * 2021-10-22 2023-05-23 Halliburton Energy Services, Inc. Processing route to design and manufacture highly configurable non-magnetic down-hole sensor collars
CN114160956A (en) * 2021-10-29 2022-03-11 苏州思萃熔接技术研究所有限公司 Friction welding method for butt joint of high-strength steel thick-wall pipe and joint

Similar Documents

Publication Publication Date Title
CN107420049A (en) A kind of full titanium alloy drilling rod of friction welding type
EP3330034B1 (en) Friction bonding method and welded structure
CN103878484B (en) The efficient docking laser welding method of a kind of layered bi-metal composite
CN105014207A (en) Vanadium/copper solid solution transition connection-based welding process for titanium-containing metal layer/pipeline steel layer composite board
WO2008109649A2 (en) Fracture resistant friction stir welding tool
PL195714B1 (en) Tubular threaded joint with reinforced stop
CN105921545A (en) Manufacturing method of pure titanium or titanium alloy/carbon steel laminar composite welded pipe
CN102642067A (en) Welding method of low-magnetic steel
CN104942521B (en) A kind of method that use frock reduces Internal Hole Deformation after core pipeline welding
Li et al. Research status and development of titanium alloy drill pipes
CN107461158A (en) High strength friction welds heavy weight drill pipe
CN102268530B (en) Heat treatment method of weld seam of welding weighted drill pipe
CN101270445B (en) Method for manufacturing fire resistant insulated tubing
CN101181765A (en) Double-phase stainless steel progressive welding method
CA1187531A (en) Composite threaded tubular connector
JP2014181551A (en) Recessed steel pipe joint, joint steel pipe, and joint method of steel pipe
CN105234575A (en) Manufacturing method for self-elevating type offshore platform cylindrical pile leg
Vendan et al. Strength assessment using destructive testing on MIAB welded alloy steel tubes and subsequent techno-economical evaluation
CN201483165U (en) 2.25 Cr-1Mo steel butt-joint welding structure with low welding residual stress
CN208322472U (en) Composite bimetal pipe
CN206084181U (en) U of hydro -cylinder V type circumferential weld groove
CN209223338U (en) Conducive to the welded steel structure of solder circulation
CN101537542B (en) 2.25Cr-1Mo steel butt joint welding structure with low welding residual stress
CN211231887U (en) Novel anti steel pipe of buckling
CN103264207A (en) Method for butt-joint manual welding of high-strength nuclear power steel

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20171201

RJ01 Rejection of invention patent application after publication