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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 20, Issue 6 - Dec 2002
Volume 20, Issue 5 - Oct 2002
Volume 20, Issue 4 - Aug 2002
Volume 20, Issue 3 - Jun 2002
Volume 20, Issue 2 - Apr 2002
Volume 20, Issue 1 - Feb 2002
Selecting the target year
Cracking in Welds and Its Prevention(III) - Hot Cracking in Welds(II) -
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 1~2
Development of Welding Consumable far Controlling the Cold Cracking in Steel Deposited Metal
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 3~8
Testing and Inspection on Solder and Solder Joint
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 9~15
The Growth Kinetics of Intermetallic Compound Layer in Lead-Free Solder Joints
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 16~23
Trends of Electronic Packaging and Characteristics Evaluation by Shape of Solder Joints
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 24~30
The Estimate of Progress Conditions and Operation Property/Reliability of Pb-Free
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 31~36
Failure Analysis for BGA/CSP Solder Joints
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 37~45
Technical Development using High Strength Steel of mP Type on Automobile Parts
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 46~53
The expolitation of substitute material and new manufacturing technology of the automobile body panel for next generation cars have been steadily professed by advanced automobile companies. High strength steel of TRIP (Transformation of Induced Plasticity) type is developed in response to demands about crash safety and high strength of automobile. In this study, basic technologies can fix up problems occurring on the mass production and applied to the other forming methods will be prepared through rasping a property of TRIP material.
Wear Resistance Characteristics of Iron System MAG Weld Overlays with Chromium and Niobium Carbide Composite
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 54~59
Overlays is a treatment of the surface and near-surface regions of a material to allow the surface to perform functions that are distinct from those frictions demanded far the bulk of the material. Welding, thermal spray, quenching, carburizing and nitration have been used as the surface treatment. Especially, weld overlay is a relatively thick layer of filler metal applied to a carbon or low-alloy steel base metal for the purpose of providing a wear resistant surface. In this study, weld overlay was performed by MAG welding on the base metal(SS400) with filler metal which contain composite powders(
) and solid wire(JIS-YGW11). Characteristics of hardness and wear resistance on overlays were analyzed by EDS, EPMA, XRD and microstructures. Carbide formations were
and NbC phases. And carbide volume fraction, hardness and specific wear resistance of overlays were increased with increasing powder feed rate and decreasing wire fred rate. Hardness and wear resistance were almost proportioned to carbide volume fraction of overlay.
A Study on the Relation between Bead Shape and Welding Parameters of GMA Welding far Die Remodeling
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 60~66
Almost every die fur automobiles must be corrected or remodeled for minor geometrical changes or for better hardness characteristics by arc welding process. Although many other kinds of arc welding processes have been automated with robots, this molten metal deposition process for die remodeling still depend entirely on experienced welders. In this study, the database for bead shapes with respect to welding parameters are constructed by experiments to automate the molten metal deposition by arc welding process. And the changes of welding parameters for inclined base metal are studied to consider the effect of die geometries fur the welding process.
Microstructures and Mechanical Properties of Friction Stir Welded High Strength Steels far Shipbuilding
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 67~73
In an attempt to evaluate the feasibility of friction stir welding(FSW) for joining carbon steels, microstructures and mechanical properties of friction stir welded carbon steels with different grain structures were investigated. In comparison of O-type stir zone(SZ) appeared in various aluminium alloys, configuration of SZ in friction stir welded carbon steels displayed U-type. Plastically deformed pearlite band structure was identified to surround the SZ, indicating the existence of so-called thermo-mechanically affected zone(TMAZ). However, the TMAZ of carbon steels was much narrower than that of Al alloys. The microstructures of both stir zone and TMAZ revealed bainite matrix in a conventional carbon steel for shipbuilding, while, in the same region, ferrite matrix microstructures were formed in a low carbon fine grained steel. The conventional carbon steel showed superior stirring workability to that of the fine grained carbon steel. The yield and tensile strength of the friction stir welded joints were comparable to those of the base metals, and the elongation in welded joints demonstrated excellent ductility. Absorbed energy in SZ of the fine grained carbon steel was ten times higher than that obtained from conventional submerged arc weld metal of the same steel. Based on these results, the application FSW to carbon steels was found to be feasible.
The Influence of Chemical Compositions of Weld Metal and Welding Conditions on Hot Cracking by Hot Cracking Test
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 74~83
In order to investigate the hot cracking phenomena of the Inconel 690 overlay welds, the hot cracking test(modified Varestraint test) was performed by varying augmented strain and welding speed in GTAW. A total of five kinds of specimens was used in the hot cracking test. The specimens used were two kinds of one layer specimens that were composed of just Inconel 690 deposited metal and three kinds of double layer specimens that were composed with as upper part of Inconel 690 weld metal and lower part of SA508 cl.3 or STS 309L. The main results are as fo11ows: In the welds composed of just Inconel 690, as the augmented strain was more increased and the welding speed was more decreased, the extent of cracking was more increased. And these cracks were mainly solidification cracks, and liquation cracks were also observed partially in HAZ. And hot cracking susceptibily of Inconel 690 welds by using filler metals containing Nb were higher than that of the welds with Nb free. The hot cracking susceptibility of Inconel 690 weld metal was increased with dilution of SA 508 cl.3 and STS 309L, and the influence of SA 508 cl.3 was higher than that of 575 309L. The results of calculation of
in Inconel 690 weld metal changed by dilution with base metal or neighboring welds were agreed well with the results of hot cracking test in this study. Therefore, it was expected that the hot cracking was considerably decreased or prevented by using proper welding conditions such as lower heat input, filler metals, base metal and neighboring welds.
Prediction Model for Relaxation of Welding Residual Stress under Fatigue Loads
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 84~90
The strength and the life of welded components are affected extensively by the residual stresses distributed around their weldments not only under static loads, but also fatigue loads. The residual stress can be superimposed with externally applied loads, so that unexpected deformations and failures of members will be occurred. These residual stresses are not kept constant, but relaxed or redistributed during in service. Under static loads the relaxation takes place when the external stress superimposed with the residual stress exceeds locally the yield stress of material used. It is shown that under fatigue loads the residual stress is considerably relieved by the first or flew cycle loading, and then gradually relaxed with increasing loading cycles. In this study the phenomenon and mechanism of the stress relaxation by mechanical means were investigated and a model to predict quantitatively the residual stress relaxation for the case of static and fatigue loading condition was proposed.
Effects of Nitrogen on the Microstructure and Toughness of HAZ in Ti-Containing Steel
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 91~97
Variation of HAZ toughness of Ti-containing steel with nitrogen content was investigated and interpreted in terms of its microstructure and the amount of soluble nitrogen present. The amounts of Ti and Al combined in TiN and AlN, respectively, in HAZ at
peak temperature were less than those in base plate; 55~88% in TiN and 21~28% in AlN, indicating the dissolution of nitrifies in HAZ. The calculated amounts of soluble nitrogen using the thermodynamic analysis showed a good agreement with the measured values in other experiment. Therefore, the analysis can be used to estimate the amount of soluble nitrogen in HAZ. Simulated HAZ toughness was influenced not only by its microstructure but also by the amount of soluble nitrogen present after the formation of BN during the cooling cycle of welding. It showed maximum value when the nitrogen content is in stoichiometric ratio with titanium content, showing that soluble nitrogen in HAZ is detrimental to its toughness.
Microstructural Characteristics of Zircaloy-4 Nuclear Fuel Cladding Welds by Resistance Upset Welding Processes
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 98~104
A study on microstructures of welds for Zircaloy-4 sheath end closure by the resistance upset welding methods was carried out. Two upset welding process variations such as magnetic farce and multi-impulse resistance welding were used. Grain size and microhardness across welds were analysed in terms of welding parameters. Magnetic farce resistance weld with one cycle of unbalanced mode has smaller upset length and
size in heat affected zone than those of multi-impulse resistance weld because of lower heat input and shorter welding time. Heat affected zone formed by two upset resistance welding variations revealed fine Widmanstatten structure or martensitic
structure due to the high heating rate and foster cooling rate. Magnetic force resistance welds showed recrystallized grains before grain growth, whereas multi-impulse resistance welds showed full grain growth.
A Study on the Mechanical Characteristic in Al 6061 Alloys welded by Friction Stir Welding
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 105~108
Al-alloy is utilized widely as a light-weight material to an automobile, a vessel and many kind of equipment, due to the light-weight and its characteristics that is a good tensile strength, elongation and tenacity for bearing heavy load and weight. Al-alloy has the good property of hot working, cold working and corrosion-resistant. But the exiting fusion welding by using Al has some economical and technical problems, but on the other hand, Friction Stir Welding (FSW) that is new joining method can settle the disadvantages that occur to the fusion welding and Is being applied and extended into the various industry fields. On this study, To analyze accurately the mechanical properties of joining area by FSW in Al 6061 alloy by using finite analysis program with finite element method. The size of HAZ and the thermal distribution is simulated and the mechanical properties around the FSW joining area to the Al-alloy 6061 is examined.
Effect of Assist Gas on Laser Induced Plasma and Bead Formation in Welding of Structural Steel by CW Nd:YAG Laser
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 109~115
In this study high power Nd:YAG laser welding of structural steel was investigated. For the test steel blocks of
were cut and machined, and bead-on-plate weld was made on the machined surface. Argon, nitrogen, helium, dry air or mixed gases were used to find the effect of shielding conditions on the bead formation. Results demonstrated that there were Fe I rich region and Fe II rich region in the laser induced plasma column based on the spectral analysis with S-2000 field spectrometer The Fe I region was located at the root of the column near keyhole opening. On the other hand, Fe II region was found at the middle of the plasma column. In the Nd:YAG laser welding, Fe I region emitted continuum which had peak value at wave length of around 710nm, and Fe II region had the peak at 580nm. In the welding of steel by
laser, however, no continuum was observed. There showed two groups of strong spikes in the
laser welding; the first group was displayed at the wave band of 450-560nm. This spike group emitted stronger intensity of light and sharper peaks than those group at 680-800nm.
A Study fur Wettability of Silicate Glasses on Silicon Nitride
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 116~121
For the accumulation of a fundamental knowledge about the behavior of glass solder during the joining of ceramics, the wettability of solder on silicon nitride have been measured by sessile drop method.
g1ass solder and oxynitride glass solders were selected as examples while silicon nitride which were used as substrates. Contact angle of solder on silicon nitride didn't decrease with time at high nitrogen content in the solder, but low nitrogen content in solders have the time-dependent property. Reason which contact angle of low nitrogen content in solders decrease on silicon nitride was that diffusion of nitrogen take place between solder and silicon nitride.
A Study on the Lap Joint
Laser Welding of Different Gauge Sheets Using ANOVA in Characteristic Zones
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 122~128
The laser welding in the automotive industries has been used widely for the butt joint of blank sheets rather than the lap joint of automotive body panels. But as a substitute far the spot welding of automotive body panels, the so called three dimensional laser welding will be important far the body panel engineers. Specially the laser welding of body panels with a smooth weld line is applied increasingly, for example, to the side panels. So far, some criteria of the laser weld quality was suggested by in-house regulations or national standards from experiences and/or rule of thumbs. In the manufacturing places, a go or no-go criterion is adopted because of the simplicity or a lack of rational criteria. It is true specially for the selection of the process parameters, which gives the basic causes for the good quality of laser welds. In this study, the effects of joint combination, gap and welding speed on the lap joint
laser welding of two mild steel sheets with different thicknesses are obtained through a
factorial experiment. The results of the weld quality are statistically analysed using analysis of variance (ANOVA) and compared between two characteristic zones, which are separated by the type of sectional shapes and the level of input energy per volume. The thickness combinations are 0.8mm/1.2mm, 1.2mm/0.8mm of mild steel sheets. The welding speed covers from the deep penetration to the partial penetration. The gap size has three levels of no-gap, 0.16m, and 0.26mm. The bead width, penetration depth and input energy per volume are measured and used as the weld quality criteria.
Analysis of Welding Deformation by Equivalent Load Method on Steel Structures
Journal of Welding and Joining, volume 20, issue 3, 2002, Pages 129~137
This study presents a new method to derive the constraint coefficient from the degree of angular deformation caused by welding, as measured experimentally by varying the shape of welded joints and the magnitude of constraints and from analysis results given by the elastic FEM method. The equivalent load was then calculated with this constraint coefficient. The validity of the numerical analysis involved in this new method was confirmed by its agreement with the experimental results. As for the effects of the constraints based on the shape of the welded joints in the case of Butt welding when the constraint coefficients are not considered, the deformed quantity produced by analysis is larger that produced by experiment and consequently is largely affected by the constraints. However, in the case of Fillet welding, the deformed quantity is seldom affected regardless of constraint coefficient considerations.