MAIN TOPICS，ABSTRACTS & KEY WORDS

MAIN TOPICS，ABSTRACTS & KEY WORDS

Control system of variable polarity plasma arc welding based on soft PLC

Chen Shujun1, Lei Yu1, Lu Zhenyang1, Bai Lilai1, Zhang Hao2

(1.Department of Mechanical Engineering & Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China;2.Capital Aerospace Machinery Company,Beijing 100076, China).p9-12,69

Soft PLC technology is a new PC-based control technology, which has a strong network communication and data processing capabilities, and it is one of the research hotspots of automation. The welding principle of variable polarity plasma arc welding was described, and the design of distributed variable polarity plasma welding control system based on EtherCAT fieldbus and a product of Soft PLC(CoDeSys) of Germany 3S company were introduced. The system can realize the real-time control of the complex space curve trajectory and the plasma welding process, and finally the welding of the complex space curve weld was realized.

variable polarity plasma arc welding(VPPAW), soft PLC, etherCAT fieldbus, CoDeSys

Key technologies of multi-pass welding in shield structural components robotic welding

Xiao Junxiang1, Zhou Canfeng2, Jiao Xiangdong2, Zhu Jialei2, Li Xianzheng3

(1. China Railway Engineering Equipment Co., Ltd., Zhengzhou, 450016, China; 2. Beijing Higher Institution Engineering Research Center of Energy Engineering Advanced Joining Technology, Beijing Institute of Petrochemical Technology, Beijing 102617, China; 3. Tangshan Kaiyuan Robot System Co., Ltd., Tangshan 063020, Hebei, China).p13-18

Abstract Shield machine is widely used in tunneling as advanced large construction equipment. Shield machine has two obvious differences from common construction equipment, one is shield structural components are made up of steel plates with hyper-thickness, which brings huge workload, the other is the designed shield according to tunnel geological conditions has special shape, size, weight and even structure type, which brings challenges for robotic welding. In order to carry out robotic welding in shield structural components successfully, several key technologies must be solved, such as residual stress and distortion, weld seam sensing and tracking, off-line programming and teaching, and multi-robots collaboration. In the future development of shield structural components robotic welding, CAPP functions can be improved by automatic joint figure generating, intelligent groove planning, to strengthen welding process monitoring by merging multi-technologies such as virtual reality (VR), and Welding Procedure Specification (WPS) is developed, which will become important fields.

Key words： shield structural components, multi-pass welding, robotic welding

Investigation on bead appearance of Ni-Ni3Si hypereutectic alloy by electron beam welding

Jiang Siyuan1,Li Xiaopeng2,Wang Ting1,Zhang Binggang2

(1. Shandong Provincial Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209, Shandong, China; 2. Harbin Institute of Technology, State Key Laboratory of Advanced Welding and Joining, Harbin 150001, China).p19-22

Abstract The 2 mm thick Ni-Ni3Si hypereutectic alloy plate was welded by electron beam welding. The influences of different parameters on the weld appearance were studied. And the contributions of electron beam and weld speed were clarified. The results showed that the weld widths of back side and top side and the ratio of the two side increase with the increase of beam current and the decrease of welding speed. The weld appearance turns to be a goblet-like shape at high welding speed and low beam current. The welding speed is significant for the top side weld width while the beam current is more significant for the back side weld width and the ratio of weld back width and weld top width.

Key words： Ni-Ni3Si hypereutectic alloy, bead formation, welding parameter

Research on laser overlap welding processing parameters of stainless steel effect of welding parameters on weld profiles

Liang Hang1,2, Jiang Yunlu1, Chen Huaining1, Du Yin3

(1.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China； 2.School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China；3.Siasun Robot & Automation Co. Ltd., Shenyang 110168, China).p23-28

Abstract The study on non-penetrating laser welding of 3 mm-thick stainless steel sheets by fiber laser was conducted. The threshold interval of power density of stainless steel in fiber laser welding was obtained. The laser power ofPand welding speed ofvwere changed in different modes, the effects of which on the color of weld backs and the weld sizes were contrasted and analyzed after recording the back colors of weld seam and measuring the weld cross-section sizes, which include surface seam width, middle weld width, and penetration. The results indicate that when the welding speed is 5 cm/s, the laser power density threshold interval for stainless steel fiber laser penetration welding is 3.19～3.61 kW/mm2. Either by increasing the laser power or by reducing the welding speed, to increaseP/vat the same proportion, will enlarge the surface seam width and the penetration, but the former is more effective. As for the effects on middle weld width, the two modes are slightly different. And the changes of weld back colors are similar. WhenP/vremains constant, which means the power and speed are increased at the same proportion, the surface seam width is changed little and the middle weld width is increased. With regard to the penetration, it is increased first and then stays unchanged. In this mode, the colors of weld back are different. The mode of reducing welding speed is more effective in improving tensile-shear strength of overlap joint.

Key words： fiber laser welding, welding parameters, weld shape characterization parameters, threshold of power density

Microstructure and wear resistance of Fe-15Cr-3.5B-xC hardfacing alloys

Jiang Debing1, He Dingyong1, Zhou Zheng1, Tan Zhen1, Wang Guohong2

(1. College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China; 2. Beijing Engineering Research Center of Eco-materials and LCA , Beijing 100124, China).p28-31

Abstract Fe-15Cr-3.5B-xC(x=0.1, 0.5, 1.0wt.%)hardfacing alloys with different carbon contents were deposited by flux-cored wire using metal active gas arc welding (MAG). The effects of carbon contents on microstructure of the hardfacing alloy were analyzed by optical microscope, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The macro hardness and wear resistance of hardfacing alloys were tested. The results indicate that Fe-15Cr-3.5B-xC hardfacing alloys consisted of M2B, Fe2B, M23(B,C)6, M3(B,C) and matrix, which contained ferrite, austenite and Fe-Cr solid solutions. With the increasing carbon content, the volume fraction of plate strip M2B decreases. Although the hardness of hardfacing alloys is improved, but wear resistance decreases. The main wear mechanism referred to furrows which caused by plastic deformation, brittle fracture and fall off of hard phase.

Key words： hardfacing alloys, microstructure, wear resistance

Research progress in friction stir welding of polymer and polymer composites

Huang Yongxian, Meng Xiangchen, Wang Yaobin, Feng Jicai

(State Key Laboratory of Advanced Welding and Joining，Harbin Institute of Technology，Harbin 150001，China).p32-37

Abstract Friction stir welding/processing (FSW/P), involved temperature, mechanics, metallurgy and their interaction, is highly complex solid state joining and processing technology, which has been widely used to join aluminum alloy, titanium alloy and the other materials which is difficultly welded by fusion welding. Recently, researchers at home and abroad proposed that FSW has potential to weld polymers and polymer matrix composites. In this review, current understanding and development of the FSW of polymers and polymer matrix composites were addressed, such as joint formation, process, microstructures, mechanical properties, materials flow and new technologies of FSW/P. On this base, further scientific research and engineering development of FSW/P processes were identified.

Key words： polymers/polymer matrix composites, friction stir welding/processing, material flow

Application and research of computer simulation and emulation technology in underwater welding

Zhang Linlin, Li Haixin, Yang Zhenlin, Yin Ziqiang

(Institute of Oceanographic Instrumentation, Shandong Academy of Sciences, Qingdao 266001, Shandong, China).p38-41

Abstract With the rapid development of computer technology, computer simulation and emulation technology have been widely used as one of important means to study the welding process. In this paper, the application and research status of computer simulation and emulation technology in underwater welding were described. It focuses on the application of finite difference method, finite element method and finite volume method in the underwater welding. Furthermore, the simulation methods, principles, modeling and analytical methods in research were introduced. The current problems and future directions of research were also proposed.

Key words： computer simulation, emulation, underwater welding

Effect of trace Ag particles on microstructure and reliability of Sn-58Bi lead-free solder joints

Zhu Lu, Yang Li, Song Bingbing, Liu Haixiang

(School of Automotive Engineering, Changshu Institute of Technology, Changshu 215500, Jiangsu, China).p42-44

Abstract The effect of nano Ag particles on the wettability, microstructure, interface IMC and mechanical properties of Sn-58Bi soldered joints was studied. The results showed that the addition of Ag particles can refine the microstructure of the soldered joints. The microstructure of the composite solder shows the trend of the first refinement after coarsening with the increase of Ag content. The addition of Ag particles increases the thickness of the interface IMC, and the IMC thickness increases with the increase of the Ag particle content in the composite solder. Ag particles addition can improve the spreadability and it shows a trend of first increase and then decrease with the content of Ag particles being increased. The tensile properties of soldered joints can be improved by adding proper amount of Ag particles, and the tensile properties of the soldered joints increase first and then decrease with the increase of the content of Ag particles. The optimum addition amount of Ag for Sn-58Bi solder is about 0.5wt.%.

Key words： lead-free solder, microstructure, interface IMC, spreadability, tensile property

Relationship between forming quality and performances of 6061 aluminum alloy joint and friction stir welding parameters

Zhu Hai1， Sun Long1，Peng Chunming2, Sun Jinrui1， Tang Huakun1,Yin Zhiyuan2

(1.College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150040, China;2.Baoji Steel Pipe Karamay Co.,Ltd., Baoji 834000, Shaanxi, China).p45-48

Abstract Aiming at the 3 mm thick 6061 aluminum alloy plate, the influences of friction stir welding process parameters on the quality and performances of the joint were studied. The pressure of the shaft shoulder mainly affect the joint appearance, the rotational speed and the welding speed mainly affect the joint quality. By changing the above parameters, the change of the joint appearance and the tensile strength were observed and analyzed. The results show that when the pressure of the shoulder is 0.2 mm, the surface of the weld is good, the defect is less and the tensile strength is high. When the rotational speed of the stir is high or the welding speed is low, the appearance of the joint is good. When the rotational speed is 950 r/min and the welding speed is 37.5 mm/min, the welded joint has the highest tensile strength. Under the condition of the proper match between rotational speed and the welding speed , the welded joints with high tensile strength can be obtained.

Key words： friction stirs welding, 6061 aluminum, alloy joint quality, tensile strength

Research on mechanical properties of non-magnetic wear resistant and its application

Ba Lujun

(Shengli Oil Field Bohai Pipe Tools Co., Ltd., Dongying 257200, Shandong, China).p49-52

Abstract The microstructure, hardness, abrasive wear resistance and magnetic permeability of the coating were investigated though the metallographic test, Rockwell hardness tester, abrasive test and magnetoconductivity. The results show that micron grade niobium carbide hard phase forms in the microstructure of Non-magnetic hardbanding, the dispersed distribution niobium carbide hard phase not only improves the wear resistance of the Non-magnetic hardbanding, but also enhances the crack resistance. Therefore, the Rockwell hardness and wear resistance of the non-magnetic hardbanding is better than that of the non-magnetic steel PT530.

Key words： non-magnetic drilling tool, non-magnetic hardbanding, hardfacing

Effects of process parameters on TIG-MIG hybrid welding process

Bi Xuesong, Ma Ruifang, Sun Xiao

(Tangshan Kaiyuan Welding Automation Technology Institute Co., Ltd., Tangshan 063000, Hebei, China).p53-56

Abstract A TIG-MIG hybrid welding system was set up, and a series of experiments were conducted at different welding currents, torch angles and arc distances．The results show that, when the shielding gas is pure argon gas, the hybrid welding process can be stable, and the TIG welding current should be higher than MIG welding current. The torch angles have no obvious influence on the hybrid welding process and weld appearance. The arc distance has some influences on the weld appearance.

Key words： TIG-MIG hybrid welding, welding arc, welding current, weld appearance

Studies on welding of steel-aluminum dissimilar metal based on the ship

Tan Anquan1，Liu Yuandan2

(1.China Classification Society Chongqing Branch, Chongqing 401121, China；2. CSSC Huangpu Wenchong Shipbuilding Co.,Ltd, Guangzhou 510715, China).p56-60

Abstract Based on the properties of the steel-aluminum transition joints and current status of dissimilar materials welding between steel and aluminum, the structural characteristic, connection form among the joint and the connection between the steel hull and the aluminum alloy superstructure were introduced. According to the shipbuilding inspections for many steel-aluminum ships, the transition joint structure, the selection for structure size, welding parameters optimization, the actual welding requirements and so on were analyzed. And no delamination defects in steel-aluminum transition joint were found during the ship operation, the design and welding process would be of certain significance for other ships.

Key words： steel-aluminum transition joint, aluminum, welding process, ship, welding

Study on spot welding parameters of common steel plate and its applications based on intermediate frequency spot welding machine

Wang Gang, Wang Liangtao

(Shanghai Volkswagen Co. Ltd., Shanghai 201805, China).p61-65

Abstract Spot welding is the most important welding method in automotive industry, and the traditional main frequency spot welding machines has some shortcomings such as short life, energy waste, low power factor and poor quality stability. While the new intermediate frequency spot welding machines make up the defects of the traditional welding equipment. Based on the intermediate frequency welding machine with common plate, the effect of welding parameters on welding quality was studied. Combining with the actual production, data fitting, computing optimization, parameters ranges for different plates combinations were found. For different thickness combinations with different welding parameters, welded spot surface quality, microstructure and microscopic structure were studied. The engineering application shows that this method is convenient to find accurate and efficient parameters selection, especially in the new car project in the process of trial production and parameters optimization it has remarkable effects.

Key words： spot welding, intermediate frequency welding machine, data processing, engineering application

Design of resistance welding system for collector of cylindrical battery

Sun Leiming，Wu Manman

(Department of Electrical Engineering, Henan Polytechnic, Zhengzhou 450046, China).p66-69

Abstract For cylindrical battery and collector resistance spot welding , six-station welding system was designed, which consists the feeding station, collecting material, welding station, pre-bending station, bending station and blanking station, and each station runs at the same time, so the production efficiency is improve. The entire system realizes the automatic feeding and unloading parts, automatic welding, and automatic bending processing after welding, which improves the degree of automation, the human cost is saved.

Key words： collector, resistance welding, six stations, automation

Exploration on training mode of welding automation talents in intelligent manufacturing environment

Wang Guoan1，Dai Jianshu2，Huang Haibo1, Liu Xiaohui3，Hou Guoqing1

(1. Guangxi Liugong Machinery Co.,Ltd., Liuzhou 545007, Guangxi, China；2. Guangxi Technological College of Machinery and Electricity, Nanning 530007, China；3. Guangxi Technician College of Machinery and Electricity, Liuzhou 545005, Guangxi, China).p70-72

Abstract After the implementation of the strategic plan of “made in China 2025”, it puts forward a new challenge to the training mode of welding automation talents. On the cultivation of the new mode is the priority task for government, industry association, and professional training institutions. A new type of welding automation talents training mode was presented, and a new idea for the future training of welding automation talents was proposed.

Key words： intelligent manufacturing, welding automation, welding robot, talents training

编辑 韩 柯