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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Welding and Joining
Journal Basic Information
Journal DOI :
The Korean Welding and Joining Society
Editor in Chief :
Volume & Issues
Volume 17, Issue 6 - Dec 1999
Volume 17, Issue 5 - Oct 1999
Volume 17, Issue 4 - Aug 1999
Volume 17, Issue 3 - Jun 1999
Volume 17, Issue 2 - Apr 1999
Volume 17, Issue 1 - Feb 1999
Selecting the target year
Rapid Prototyping Processes for Direct Metal Fabrication
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 1~7
State of the Art in Laser-Assisted Rapid Prototyping of Metallic Parts
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 8~12
Development of Metal Based Rapid Prototyping by Using GMA Welding Processes
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 13~16
A New Concept of Parallel Mechanism Machine Tool for Rapid Machining
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 17~21
Application of Expert System to Obtained the Optimal Welding Parameters
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 22~25
Laser Weld Bead by Using Multiple Regression
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 26~35
On the laser weld production line, a slight alteration of the welding condition changes the bead size and the strength of the weldment. The measurement system is produced by using three photo-diodes for detection of the plasma and spatter signal in
laser welding. The relationship between the sensor signals of plasma or spatter and the bead shape, and the mechanism of the plasma and spatter were analyzed for the bead size estimation. The penetration depth and the bead width were estimated using the multiple regression analysis.
Effect of Si on Spatter Generation and Droplet Transfer Phenomena of MAG Wwlding
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 36~43
The effect of Si content in welding wires on spattering characteristics and droplet transfer phenomena was studied. In MAG welding using 80% Ar-20%
shielding gas, spattering characteristics and droplet transfer phenomena were varied with Si content of wire. With increasing Si content, the spattering ratio and the ratio of large size spatter
were increased. The increase of Si content in molten metal made surface tension increase due to reduction of oxygen content, which resulted from deoxidizing action of silicon. The increase of surface tension resulted in unstable transfer phenomena and arc instability in both short circuit and spray region. With changing Si content of wire, spattering characteristics and droplet transfer phenomena was directly influenced by the variation of surface tension, compared with the effect of arc stability.
Development of Welding Information System for Power and Industrial Plant
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 44~49
Power and industrial plant use various welding processes and many kinds of materials. Thus, it is a difficult task to get the proper welding information. In this research, a welding information system was developed to solve the difficulty. It consists of database system, knowledge base system and diagram analysis programs. Database system contains a large database and various searching method corresponding to the kind of information. A large part of welding information is managed by this database system. Knowledge based system is used for decision of proper welding process and analysis of weld defects. It has conversion program from text to knowledge, and inference mechanism. Finally, Diagram analysis programs carry out the calculation of ferrite content in the weld metal. By the calculation, a crack occurrence can be avoided. The developed system can be a useful tool for welding in the field of power and industrial plant.
A Study on Low Temperature Strength and Fatigue Strength of Austenitic Stainless Steel for Membrane Type LNG Tank
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 50~54
Feasibility study of the application of a developed annealed austenitic stainless steel at cryogenic temperature has been performed for membrane tank of LNG ship. Chemical properties of developed stainless steel are compared with a domestic commercial stainless steel and a foreign stainless steel which are used for LNG ships. Tensile properties at cryogenic temperature and fatigue strength at room temperature are measured for but and lap joints which are TIG welded specimens. Developed stainless steel having a small amount of titanium component shows the finest grain size in the HAZ, compared with the other stainless steel studied. Tensile strength, elongation and fatigue strength of the developed stainless steel are equal to those of the foreign stainless steel studied and are higher than the domestic commercial stainless steel studied.
Effects of M-A Constituents on Toughness in the ICCG HAZ of SA508-cl.3 Pressure Vessel Steel
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 55~65
Metallurgical factors influencing toughness of the Intercritically Reheated Coarse-Grained Heat Affected Zone (ICCG HAZ) of multiple welded SA508-cl.3 Reactor Pressure Vessel Steel were evaluated. The recrystallized austenite formed along the prior austenite grain boundaries and late interfaced on heating to the intercritical range was transformed to bainite and/or martensite during cooling. The newly formed martensite always included some retained austenite(M-A constituents). The characteristics(amount, hardness, density, and size) of M-A constituents were found to be strongly associated with both peak temperature and cooling time(△t8/5(2)) of last pass. Toughness in the ICCG HAZ was deteriorated with increasing amount of M-A constituents which was increased with increasing the last peak temperature within the intercritical temperature range. Meanwhile, for the same intercritical peak temperature, toughness was decreased with increasing cooling time. When cooling time was short, the dominant factor influencing toughness of the ICCG HAZ was amount of M-A constituents. However, when cooling time was lengthened, the hardness difference between M-A constituents and softened matrix(tempered martensite) was found to be the dominant factor.
Corrosion Behavior Analysis of the Weld Joint between Stainless Steel and Carbon Steel
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 66~70
In order to investigate the quantitative behavior of galvanic corrosion in weld joints between stainless std이 and carbon steel, electrochemical polarization experiments were performed at pH4, pH7 and pH10 with boric acid concentration 4000ppm, and water temperature were selected as
. As the results, the galvanic corrosion phenomena of carbon steel weld material at
times higher corrosion rate than that at
condition. The corrosion rate of stainless steel was almost inedependent of the variation of pH. The significant corrosion rates of carbon steel and the weld joint of carbon-carbon steel were observed at pH 4.
A Study on Development of Laser Welding System for Bellows Outside Ege Using Vision Sensor
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 71~78
The welded metal bellows is commonly manufactured by welding pairs of washer-shaped discs of thin sheet metal stamped from strip stock in thickness from 0.025 to 0.254 mm. The discs, or diaphragms, are formed with mating circumferential corrugations. In this study, the diaphragms were welded by using a CW Nd: YAG laser to form metal bellows. The bellows was fixed on a jig and compressed axially, while Cu-rings were installed between belows edges for intimate contact of edges. The difference between the inner diameter of bellows and jig shaft causes an eccentricity, while the tolerance between motor shaft and jig shaft causes a wobble type motion. A vision sensor which is based on the optical triangulation was used for seam tracking. An image processing algorithm which can distinguish the image by bellows edge from that by Cu-ring was developed. The geometric relationship which describes the eccentricity and wobble type motion was modeled. The seam tracking using the image processing algorithm and the geometric modeling was performed successfully.
Characteristics of Brazed Joint of Sintered Bronze/steel Using Ag-Cu-Zn Type Filler Materials
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 79~89
The study was carried out to examine in more detail metallurgical and mechanical properties of brazed joints of diamond cutting wheel. In this work, shank(mild steel) and sintered bronze-base tips were brazed with three different filler materials(W-40, BAgl and BAg3S). The machine used in this work was a high frequency induction brazing equipment. The joint thickness, porosities and microstructure of brazed joints with brazing variables(brazing temperature, holding time) were evaluated with OLM, SEM, EDS and XRD. Bending(torque) test was also performed to evaluate strength of brazed joints. Further wetting test was performed in a vacuum furnace in order to evaluate the wettability of filler metals on base metals9shank and tips). The brazing temperature had a strong influence on the joint strength and the optimum brazing temperature range was about
for the bronze/steel combinations. The strength of the brazed joint was found to be influenced by the three factors : degree of reaction region, porosity content, joint thickness. The reaction region was formed in the bronze-base tip adjacent to the joint. The reaction region resulted in a bad influence on the strength due to the formation of Cu5.6Sn, CuZn4,
and CdAg, etc. Porosities increased as brazing variables(brazing temperature, holding time) increased, and the brazed joints with porosities of less than about 3-5% had an optimum strength for the bronze-base tip.
A Study of the High Reliability in Plastic BGA Solder Joints
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 90~95
The increase in high speed, multi-function and high I/O pin semiconductor devices highly demands high pin count, very thin, and high density packages. BGA is one of the solutions, but the package has demerits in package reliability, surface mounting problems due to the PCB warpage and solder joint crack related with TCE mismatch between the materials. On this study to verify the thermal fatigue lifetime of the solder joint FEM and experiments were performed after surface mounting BGA with different solder composition and reliability conditions. FEM showed optimum composition of Ag3.2-Sn96.5 and under the composition minimum creep deformation of the solder joint was calculated, and the thermal fatigue lifetime was improved. In view of temperature cycle condition, the conditions of
showed minimum lifetime and t was 1/3 of
condition. Test board was prepared and solder joint crack was verified. Until 1000cycle on soder joint crack was observed.
Microstructures and Impact Properties of 500mm Single Pass Electrogas Weldment for EH36 TMCP steels
Journal of Welding and Joining, volume 17, issue 3, 1999, Pages 96~101
Microstructures and mechanical properties of weldments were studied for EH36 TMCP higher-strength hull steel with electrogas welding jprocess. In case of a newly designed EH36 TMCP steel for large heat input welding process, the Microstructures of HAZ shows more narrow width of grain coarsed region than that of conventional EH36 TMCP weldments, the amount of acicular ferrite, which is beneficial to impact toughness, increased while the amount of grain-boundary ferrite decreased. Charpy V-notched impact tests show that a newly designed EH36 TMCP steel weldment satisfies all the requirement of specifications, especially at the fusion line +2mm where the conventional EH36 TMCP steel fails to exceed the requirement.