Main Topics,Abstracts &Key Words
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2004, Vol.25 , N o .4 T RAN SACT IO NS OF T HE CHINA W EL DING IN ST IT UT IO N Ⅲ MAIN TOPICS , ABSTRACTS &KEY WORDS Coaxial monitoring and penetration control in CO2 laser welding(Ⅰ)——— developed by us is discussed .The swing welding experiment for V-type w eld- Penetration status characteristics and coaxial monitoring ZHAGN Xu- ing groove is done and the results show that the system has high resolution of Dong , CHEN Wu-zhu, LIU Chun , GUO Jing(Department of Mechanical tracing w eld in real time, works stably and efficiently .The shape of weld Engineering , Tsinghua University, Beijing 100084 , China).p1 -4 mark is good . Abstract:The various penetration status in deep penetration laser weld- Key words:real-time control;structure-light vision ;visual measure- ing is classified .The w elding condition and the weld bead formation of “w eld ment;visual control;arc welding robot pool penetration” and “ moderate full penetration (keyhole penetration)” are described .A system for coaxial monitoring the penetration status in CO2 laser Analysis of interfacial structure of Ti/ Cu/ Ti diffusion brazing heated with w elding is established.The influence of welding process variables and penetra- oxy-acetylene flame Yuan Qing-long , Su Yon-gan, Tang Bin , Xu Zhong tion status on the coaxial optical signal is studied in laser w elding of planar (Institute of Surface Engineering, Taiyuan University of Technology , plate.The experimental results show that as the heat input increases, the Taiyuan 030024 , China).p15 -18 variation slope of the signal intensity is maximal w hen the penetration status Abstract:Ti/ Cu/ Ti diffusion brazing, w hich is heated w ith oxygen- changes from “w eld pool penetration” to “moderate full penetration” . acetylene flame and pressed simultaneously , is realized under protection of the Key words:laser welding;coaxial monitoring ;penetration coating.The measurement results of interfacial microstructure, composition and cohesion strength of joint by backscattered electron , energy dispersive Pulsed MIG welding process of high strength A-l Cu alloy GUO Xu- spectroscopy and tensile test indicate that full diffusion occurs betw een Cu and ming, YANG Cheng-gang, QIAN Bai-nian , ZHANG Hong-yan(Institute of Ti in the joint w ithin the test temperature range .In the temperature range Metal Research , The Chinese Academy of Sciences, S henyang 110015 , Chi- from 840 ℃ to 870 ℃, the microstructure consists of Cu4Ti and Cu(Ti) na).p5 -9 (solid solution)in the middle part of the joint and the cohesion strength is rel- Abstract:The effects of single-wire unitary pulsed metal inert-gas ative high .In the temperature range from 870 ℃ to 900 ℃, the microstruc- (MIG), synergic pulsed MIG and double-w ires tandem MIG w elding pro- ture is composed of CuTi and Cu4Ti+Cu(Ti)(solid solution)in the middle cesses on the microstructures and properties of high strength Al-Cu alloy part of the joint and the cohesion strength is relative low .The cohesion w elds were investigated .The results showed that the enhanced stirring action strength has something to do w ith heating temperature. of the liquid metals in weld pool due to peak-current fluctuating periodically Key words:titanium ;copper foil;diffusion brazing ;oxygen-acetylene under single-wire synergic pulsed MIG w elding decreased temperature gradi- flame;interface ents and increased heterogeneous nuclei within the region of constitutional su- percooling just ahead of the solid-liquid interface.As a result, the microstruc- Dynamic focal spot and extremum effect of deep penetration of electron ture of the weld w as refined.The strength and ductility of the weld in- beam ZHOU Qi1, 3 , LIU Fang-jun2 , GUAN Qiao2(1.Ningbo Sub-a- creased.The high heat inputs and rapid w elding speed of double-wires MIG cademy of the National Weapons Science Research Academy , Ningbo w elding enhanced the formation of coarse equiaxed dendrites in the weld and 315103 , Zhejiang , China;2 .Beijing Aeronautical Manufacturing Technology increased the eutectic constituents at grain or dendrite boundaries.The Research Institute, Beijing 100024 , China;3 .Beijing University of Aeronau- strength , hardness and ductility of the w eld decreased. tics & Astronautics, Beijing 100083 , China).p19-22 Key words:high strength Al-Cu alloy ;synergic pulse;tandem metal Abstract :The measurement methods of focal spot with welding charac- inert-gas w elding;weld microstructure teristic are analyzed .Using the simple model of molten pool, the inherence relation of the different measurement methods with the w elding property is il- Study on arc welding robot visual control XU De, TU Zhi-guo , ZHAO luminated.The conception of dynamic focal spot is set up , and the factors Xiao-guang, TAN Min(The Key Laboratory of Complex System and Intelli- which influence the dynamic focal spot are discussed .Furthermore, the char- gence Science, Institute of Automation , Chinese Academy of Sciences, Bei- acters of dynamic focal spot are analyzed, and the most important character is jing 100080 , China).p10 -14 the extremum effect of deep penetration of electron beam. Abstract:A real-time arc w elding robot visual control system based on Key words:electron beam welding;dynamic focal spot ;extremum ef- local network with multi-level hierarchy is presented , w hich consists of intel- fect of deep penetration ;space-charge effect;self-focusing effect ligence and human-machine interface (HMI)level, motion planning level, motion control level and servo control level.The last three levels form local Control optimization for pulsed MIG weding machine LI He-qi, LI real-time open robot controller (LRTORC).The master computer as the Chun-xu, LI Fang , LU Guang, (Education Ministry Key Lab of Advanced first level is for visual measurement, movement command generator, w elding Processing Technology for Non-ferrous Materials, Lanzhou University of torch controller and HMI .LRTORC realizes motion planning and motion Technology , Lanzhou 730050, China).p23 -26 control of the robot.The system has the function of automated recognition Abstract :A self-designed microcomputer control system for pulsed met- and tracking weld .The principle of the visual control system and LRTORC al inert-gas(MIG)w elding power source, the selection of proportional-inte- Ⅳ M A IN T OPICS , ABST RA CTS & K EY WO RDS 2004, Vol .25 , N o .4 gral-differential(PID)algorithms, and the optimization stratege of system ement software conntrol software w ere introduod.To solve the conflict betw een proportional- integral(PI) control and real time display of w elding parameters in MIG Study on valid exponent and welded restrict of explosive welding XIE w elding, the w orking Timing Diagram of serial display component MAX Fei-hong1 ,GUAN Hui-ping1 , WANG Jun2 ,3 , LUO Guan-w ei4(1 .College of 7219 was analyzed, and the data and command transfer w ays of it and the Civil Engineering , Lanzhou Jiaotong University , Lanzhou 730070, China;2 . w ay to optimize PID control algorithms on the premise of avoiding system Yaojie Coal and Electricity Group, Lanzhou 730084 , China;3 .Xi' an Jiao- damping were improved .PI control time is only 80 μs and one bit digital dis- tong University , Xi' an 710049, China;4 .College of Mechanical-Electronics play w as refreshed every 200 times(about 16ms).The display flash problem Engineering , Lanzhou Jiaotong University , Lanzhou 730070 ,China).p35 - w as solved .The result show ed that the optimized program run very fast, re- 38 sponded very quick , and w as very accurate, and the w elding proass was very Abstract :In view of the hypothesis of upset plate move bearing and gas stable. dynamic equation in explode, blast w ave equation is made up, and explosive Key words:inverter welding power source;proportional-integral-differ- gasaction is thought vertical reflection on fixed w all.So confine of valid expo- ential controller ;serial component ;pulsed metal inert-gas w elding nent is yet deduced .It is reliable supply for practical engineering .2 # rock nitramon and petnaerythritoltetranitrate or trinitrotoluene explosive is used to Vision detecting of weld pool image for depositing copper with automatic weld aluminum upset plate and mild steel base plate, the equation upset plate TIG welding WANG Ke-hong , XIONG Liang-tong , XU Yue-lan, YU and explosive thickness can be deduced from Richter equation .It is effectual Jin(Department of Materials Science & Engineering , Nanjing University of for being used in practice by example of analysis. Science & Technology , Nanjing 210094 , China).p27 -30 Key words:explosive welding parameter;effective exponent;motive Abstract:An idea of imaging in near-infrared spectrum is proposed , and shock w ave reflected on fixed wall;gas dynamic equation two kinds of composite narrowband filter system with different imaging mechanism are designed.Images of copper w eld pool in tungsten inert-gas Safety assessment of duplex stainless steel pipe mismatch welded joints with (TIG)and pulsed TIG(PTIG)welding are obtained from the front side of surface flaw JIN Xiao-jun1, HUO Li-xing1 , ZHANG Yu-feng1 , BAI w ork pieces using normal charge coupled device sensor , and results of imaging Bing-ren2 , LI Xiao-w ei2, CAO Jun2(1.School of Material Science and Tech- w ith different observing window are discussed .Then , comparatively better nology , Tianjin University, Tianjin 300072 , China;2 .China Offshore Oil imaging windows are found , and comparatively clear images of copper w eld Engineering Ltd., Tianjin 300452 , China).p39 -42 pool are obtained .From the experiment , it can be found that it iseasy to ob- Abstract :Structure Integrity Assessment Procedure(SINTAP)-Fail- tain clear image in near-infrared spectrum in TIG welding and images obtained ure Assessment Diagram (FAD)method w as applied to the SAF2205 pipe in the base of PTIG welding are clearer than that of TIG welding .Finally, mismatch welded joints with surface flaw (The height and length are 1.1 mm the features of copper weld pool and control of depth are analyzed and re- and 2 .5 mm respectively)at the weld toe.The failure lines of analysis level 1 searched .