Research and engineering application of the arc welding pulsed controller technology

The tenacity of heat-affected zone （HAZ） will decline and the size of grains will increase, because of the overheating on HAZ when submerged are welding （SAW） is ased to thick plate with high heat input. The shaping will worsen when SAW is used to thin plate with high current at high speed. A new SAW technology, the pulsed direct current （DC） automatic SAW, will be put forward in this paper in order to overcome the above shortcomings. And a pulsed controller with micro-controller unit （MCU） as the core, nixie tube （NT） and keyboard as the man-machine conversation interface is developed. The main functions of the pulsed controller include the output of pulsed welding current and the working with twinwire. The research has widely prospects in application with significant meanings in theory and practical engineering.     

Development of motion controller and its application in automatic TIG welding system

To develop a control system of cantilever arm for barrels welding, a motion controller has been developed to rit the welding procedure. The main research fields of the controller are: (1) finding effective measures to protect the controller against inteorerences ; (2) decreasing welding current gradually in order to alleviate arc craters which are harmful to seam forming and welding quality; (3) planning the arm velocity to minimize the influence of the arm swing on arc length regulator; (4) adopting adaptive control algorithm with PD feedback and velocity feed-forward to reduce the inftuence of system inertia and velocity planning on the system transient peorormance.     

Progress of the Chinese shipbuilding industry and welding technology

ＰｒｏｇｒｅｓｓｏｆｔｈｅＣｈｉｎｅｓｅｓｈｉｐｂｕｉｌｄｉｎｇｉｎｄｕｓｔｒｙａｎｄｗｅｌｄｉｎｇｔｅｃｈｎｏｌｏｇｙ￥ＤＩＮＧＦｕｂａｏａｎｄＨＵＡＮＧＹｕｅ（ＳｈｉｐｂｕｉｌｄｉｎｇＴｅｃｈｎｏｌｏｇｙＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ，Ｓｈａ...     

Mechanism analysis of free formation of backing weld by the pulsed MAG-TIG double arc tandem welding

Because of the presence of lower-level automation and efficiency in the backing welding of medium–thick plates, pulse-metalactive-gas–metal-inert-gas(MAG–MIG) dual-arc welding was applied to backing welding of 24-mm-thick Q235-B plate and the process and mechanism of root welding with back formation were investigated. The heating position of the MAG-arc at the front of the molten pool could be adjusted by using the electromagnetic force between the MAG-arc and the MIG-arc, and part of the arc energy could work on the root face directly. By combining the arc-discharge behaviour and analysis of flow in the molten pool, the shear stress of a tungsten inert gas(TIG) arc to the molten pool could make the liquid metal flow backwards. Thus, the quality of the front and bottom liquid metal were reduced, which favored the balance and stability. Continuous and stable back formation with uniform penetration could be achieved by using the pulse MAG–TIG dual-arc welding technology.     

Development of an engineering－practical expert system for arc welding and its shell

Ｄｅｖｅｌｏｐｍｅｎｔｏｆａｎｅｎｇｉｎｅｅｒｉｎｇ－ｐｒａｃｔｉｃａｌｅｘｐｅｒｔｓｙｓｔｅｍｆｏｒａｒｃｗｅｌｄｉｎｇａｎｄｉｔｓｓｈｅｌｌＰｅｎｇＪｉｎｎｉｎｇ；ＣｈｅｎＢｉｎｇｓｅｎａｎｄＬｉｕＱｉａｎｇ（ＱｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙ，...     

Some phenomena and features of the component distributions in welding arc

Ｓｏｍｅｐｈｅｎｏｍｅｎａａｎｄｆｅａｔｕｒｅｓｏｆｔｈｅｃｏｍｐｏｎｅｎｔｄｉｓｔｒｉｂｕｔｉｏｎｓｉｎｗｅｌｄｉｎｇａｒｃ￥ＳｏｎｇＹｏｎｇｌｕｎ（ＳｏｕｔｈＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎｏｌｏｇｙ，Ｇｕａｎｇｚｈｏｕ）Ａｂｓｔｒａ...     

Effects of distance between arc and heat sink on stress and distortion in DC-LSND welding technology

The characteristics of temperatures, stresses and strains fields have been studied numerically for a titanium alloy sheet welded with an improved gas tungsten arc welding method, in which a trailing spot heat sink is introduced to control the welding stress and distortion. The impinging jet model is employed to describe the internee heat transfer between the cooling media and the top suufuce of the workpiece. The influcnee of the distance between arc and heat sink is investigated. Results show that there is an ideal range of distance. Using the ideal distance, a low stress and no distortion welding structure can be derived.     

An analysis of the dynamic resistance and the instantaneous energy of the CO2 arc welding process

A self-developed welding dynamic arc wavelet analyzer was adopted to analyze and assess the welding process of two CO2 arc welding machines. The experimental results indicate that the instantaneous energy can reflect the influence of the welding current and voltage on dynamic arc characteristic synthetically. Through calculating and analyzing the instantaneous energy, the energy during arc ignition and short circuit in CO2 welding process can be confirmed rationally, thus the foundation for the accurate design and control of the welding current and voltage can be provided. By reducing the ripple disturbance of the dynamic resistance, avoiding peak current and voltage waveform,and enhancing the transition frequency of short circuit suitably, the stability of the welding arc and the weld appearance can be improved.     

Some features of welding arc radiation

0IntroductionRadiationisanimportantphenomenonofarcweldingprocess.Essentially,itreflectsthephysicalprocessesoccUrringinthearcregion.Ithasbeennotedthattheinformationconcerningthearcprocess,suchastemperature.componentsandtheirdistributions.canberealizedthroughtheobservationofradiationbyarcself-emissionl'.ZI.Therefore,moreknowledgeaboutthefeatUresoftheradiationisneededtoenhancetheunderstandingofti)eldingarc.Inthisarticle.somephenomenaofweldingarcradiation,suchaspossiblewavelengthrangeoftheradiat…     

Some features of welding arc radiation

Ｓｏｍｅｆｅａｔｕｒｅｓｏｆｗｅｌｄｉｎｇａｒｃｒａｄｉａｔｉｏｎ￥ＳＯＮＧＹｏｎｇｌｕｎ（Ｐｒｏｆ．ＳｏｕｔｈＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎｏｌｏｇｙ，Ｇｕａｎｇｚｈｏｕ，５１０６４１，Ｃｈｉｎａ）Ａｂｓｔｒａｃｔ：Ｔｈｉｓｉｎｖｅｓ...     

Energy characteristics of the power source‐welding arc system

Analytical decisions supported by experimental data were used to determine the dependences for calculating the size of the heat-affected zone (HAZ) in multilayer welding of circumferential joints in transmission gas pipelines. Data on the dimensions of this zone are essential for evaluating the possibility of applying cold cutting in the rejection of elements of gas pipelines because of defects in circumferential welded joints or welded joints in transition rings in the vicinity of circumferential welded joints.     

Current status and prospects of welding technology in China

ＣｕｒｒｅｎｔｓｔａｔｕｓａｎｄｐｒｏｓｐｅｃｔｓｏｆｗｅｌｄｉｎｇｔｅｃｈｎｏｌｏｇｙｉｎＣｈｉｎａ￥ＳＯＮＧＴｉａｎｈｕ（ＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＭａｃｈｉｎｅｒｙＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙ，Ｂｅｉｊｉｎｇ（１０００４...     

Effect of arc physics on developing CO_2 arc welding

ＥｆｆｅｃｔｏｆａｒｃｐｈｙｓｉｃｓｏｎｄｅｖｅｌｏｐｉｎｇＣＯ_２ａｒｃｗｅｌｄｉｎｇＹｉｎＳｈｕｙｉａｎ；ａｎｄＧｅｎｇＺｈｅｎｇ（ＨａｒｂｉｎＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏｌｏｇｙ）Ａｂｓｔｒａｃｔ：Ｔｈｅｍｅｃｈａｎｉｓｍｓｏｆｗｅｌｄｆ?..     

Correction factor based double model fuzzy logic control strategy of arc voltage in pulsed MIG welding

0Introduction Improvedstabilityofweldingarclengthhasbecome increasinglyimportantforhigherweldingquality.Thesta bilityofweldingarclengthisdependentontwoaspects: oneistheintrinsicself adjustmentofarc,anotheristhe effectoftheweldingconditionparametersandthe…     

Effect of activating flux on arc shape and arc voltage in tungsten inert gas welding

The effects of activating fluxes on welding arc were investigated. A special set of water-cooling system and stainless steel were used as parent material. During welding process, high-speed camera system and oscillograph were used for capturing instantaneous arc shape and arc voltage respectively. The experimental results indicate that the SiO2 flux can increase the arc voltage, while TiO2 has no this effect on arc voltage. Compared with conventional tungsten inert gas welding （C-TIG）, it is found that the arc shape of A-TIG welding used with the SiO2 flux has changed obviously.     

Investigation on the stepping arc stud welding process

0IntroductionArc stud welding is gradually becoming an increasingimportant joining process fromthe firstpractical applicationdeveloped originally for the shipbuilding industry as a re-placement of the time consuming drilling and boltingprocess in1939[1].T…     

Investigation on the communication network of long wire transmitting in remote welding

0IntroductionThe welding is needed during a ocean engineeringconstructed and a nuclear electricity station repaired.Be-cause the survival condition of human is very severe in thelocations,the welding must be fulfilled by robot.Since thecomplete-independence robotwelding is difficultto be real-ized in terms of the current technology levels of robot,arti-ficial intelligence and sensor,the conception of remotewelding is broughtforward.In safe surroundings,the oper-ator remotely watches and contro…     

Application and prospect of computer technology in welding materials field

0ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｔｈｅｓｐｒｅａｄａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆｃｏｍｐｕｔｅｒ,ｔｈｅａｐｐｌｉｃａｔｉｏｎｏｆｃｏｍｐｕｔｅｒｉｎｗｅｌｄｉｎｇｆｉｅｌｄｂｅｃｏｍｅｓｗｉｄｅｓｐｒｅａｄａｎｄｇｏｅｓｉｎｔｏａｌｍｏｓｔｉｔｓａｌｌａｓｐｅｃｔｓ .Ａｃｃｏｒｄｉｎｇｌｙ ,ｈｏｗｔｏａｐｐｌｙＣＡＷｔｅｃｈｎｏｌｏｇｙｔｏｉｍｐｒｏｖｅｗｅｌｄｉｎｇｑｕａｌｉｔｙａｎｄｒａｉｓｅｐｒｏｄｕｃｔｉｖｅｅｆｆｉｃｉｅｎｃｙａｔｔｒａｃｔｍｏｒｅａｎｄｍｏｒｅｗｅｌｄｉｎｇｗｏｒ…     

Achievements and developing trend of welding technology in Chinese shipbuilding

0IntroductionWeldingtechnologyisoneofthefundamentaltechniqueinmodernindustry.Forshipbuilding.itisakeymanufacturingtechnique.Forinstance,consumptionofman-hourinweldingisabout30-40%ofthatofhullconstruction,andthecostofweldingisabout30-50%ofthatofhullconstruction.Weldingqualityisconsideredasavitalindexforqualityevaluationofhullconstruction.Also,weldingefficiencyisanprimaryfactorforhullconstructioncycle.Onthewhole,weldingtechnologyprogressisthepowerfordevelopmentofshipbuildingindustry.lDevelopme…     

Research and development of transnormal twin roll-casting technology

1　INTRODUCTIONThedevelopmentofmodernmaterialprocessingscienceandtechnologyhasdriventhetransnormaloutfieldsmaterialprocessingtechnologytobeafavor abledevelopingandresearchdirectionoftwinrollcastingprocess[1,2 ] .Asweallknow ,theconven tionaltwinroll casting (CTRC)hasthefollowingdisadvantages :lowrollcastingspeed ;fewkindsofa luminumalloyswhichcouldbeproduced ;segregationandinhomogeneityexistingbothonthesurfaceandinsideofCTRCstrips ,andhardto producehighqualitystripsforhighgradeperforman…