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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(II) - Cracks in Welds and Hot Cracking(I) -
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 1~3
A Study on Korean Welding Education and Qualification System(I)
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 4~12
A Study on Korean Welding Education and Qualification System(II)
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 13~20
Prediction and Control of Welding Deformation far Panel Block Structure
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 21~26
Development of Numerical Method for Assessment of Crack Initiation in Welded Joint
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 27~31
Improvements in Strength and Weldability of Cr-Mo Steel Plates for Pressure Vessels and Boiler
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 32~41
Application of Continuous Indentation Testing Method for Evaluating the Strength Performances of Weldments
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 42~49
Residual Stress Measurement on Welded Specimen by Neutron Diffraction
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 50~58
Residual stress is generated in the structures as a result of irregular elastic-plastic deformation during fabrication processes such as welding, heat treatment, and mechanical processing. There are several factors attributed to the origin of residual stresses, tensile or compressive. The stresses can be determined by destructive ways or nondestructive ways using X-ray or neutron diffraction. Although X-ray diffraction is a well established technique, it is practically limited to near-surface stresses. Neutrons penetrate easily into most materials and neutron diffraction permits non-destructive evaluation of lattice strain within the bulk of large specimens because the radiation is more deeply penetrating for metallic engineering components. This paper presented application of neutron diffraction technique to the residual stress measurement using 20 mm thick welded stainless steel plate(
Estimation of Fatigue Strength in Resistance Spot Weldment of the Vehicle Body
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 59~64
When the vehicle travels in an actual road, resistance spot weldments of the vehicle structure are exposed to complex loading state. Since the fatigue strength in resistance spot weldment of vehicle body can be determined by effect of residual stresses and loading state of driving, estimating actual loading state and considering residual stress effect are needed. In this study, Fatigue stress-fatigue life relation concerned residual stress effect was obtained by thermo elastic plastic finite element analysis. And applied loading in resistance spot weldments of vehicle body was calculated by dynamic analysis. Presumption of fatigue life was performed using proposed method
A Study on the GMA Welding Characteristics of Al5083-O Aluminum Alloy According to the Shield Gas Mixing Ratio and Heat Input
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 65~70
This study was to evaluate GMA welding characteristics of the A15083-O aluminum alloy according to the shield gas mixing ratio and heat input change. The GMA welding of the base metal was carried out with flour different shield gas mixing ratios(Ar100%+He0%, Ar67%+He33%, Ar50%+He50%, and Ar33%+He67%). Regarding the if1uence on the bead shape of the shield gas mixing ratio and heat input, the bead width was greatest in Ar100%+He0% mixture. But the penetration depth and area were greatest in Ar33%+He67% mixture considering that the lower Ax gas ratio, the higher bead depth and area. Also, dilution was also best in the shield gas mixing ratio. The size and number of deflects were least in Ar33%+He67% mixture. Higher He gas ratio resulted in less deflects detected by the radiographic inspection.
The Strain Measurement of Pure Aluminum Welded Zone by the Laser System
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 71~76
Currently knowledge of strain in welds has mainly been obtained from strain gage method; that is directly attaching the gage to the most of the material. The very flew non-contact methods are still in the early stage. One of the non-contact methods is by the use of the laser that has high-level of the accuracy for the measurement, and this laser also has excellent characteristics on which many studies for its applications are focused throughout the many fields. The paper is on the measurement of the strain caused by the characteristics and the temperature changes of the GTA welded zone employed with 3D ESPI system that is functionally modified through the laser ESPI system. This system may be applied the steel plate such as for the electronics, chemistry, flood instrument and electronic appliances.
A Study on the Characteristics of Sn-Ag-X Solder Joint
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 77~81
Many kinds of Pb-free solder have been investigated because of the environmental concerns. Sn-Ag-Cu system is well blown as most competitive Pb-free solder. However, since Sn-Ag-Cu system has relatively high melting point compared to Sn-Pb eutectic, it may a limitation, the some application. In this study, Bi and In contained solder of
which has relatively lower melting point,
, was investigated.
solder ball of
diameter was set on the Ni/Cu/Cr-UBM and reflow soldered in the range of
for 5~15s. The maximum shear strength of the solder ball was around 170mN by reflowing at
for 10s. Intermetallic compound formed on the UBM of Si-wafer was analysed by SEM(scanning electron microscope) and XRD(X-ray diffractometer).
Hot Cracking Behavior in Inconel 690 Overlay Welds on Mn-Ni-Cr-Mo Steel for Pressure Vessels
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 82~89
In order to clarify hot cracking phenomena occurred in Inconel 690 welds and it's prevention, in this study, the cracking behavior and the influence of welding variables on cracking in Inconel 690 overlay welds on Mn-Ni-Cr-Mo steel(SA 508 cl.3) for pressure vessel were investigated by using mock-up test. The main results are as follows: The cracks in Inconel 690 overlay welds were mainly generated near the start and the end part of welding beads adjacent to STS 309L welded outside of Inconel 690 welds. Most of the cracks showed typical solidification crack, and also it was assumed that there was possibility of liquation cracking in HAZ. The existence of Nb constituents or concentration of Nb was recognized on the fracture facets of the solidification cracks in the welds by SMAW. Therefore Nb was considered to be the main factor of the solidification cracking. As the weld heat input was more increased and the weld bead length was longer, the extent of cracking was more increased. Moreover the extent of cracking was considerably decreased by changing of welding sequence to the start and the end part of welds. Hot cracking in welds by GTAW was considerably decreased as compared with that of SMAW. And cracks were well generated in the Inconel 690 overlay welds adjacent to 575 309L welds. This means that the hot cracking susceptibility of Inconel 690 welds was largely varied by chemical components and/or compositions of filter metals, base metals and neighboring welds.
The Improvement of 2nd Level Solder Joint Reliability fur Flip Chip Ball Grid Array
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 90~94
FC-BGA has advantages over other interconnection methods including high I/O counts, better electrical performance, high throughput, and low profile. But, FC-BGA has a lot of reliability issues. The 2nd level solder joint reliability of the FC-BGA with large chip on laminate substrate was studied in this paper. The purpose of this study is to discuss solder joint failures of 2nd level thermal cycling test. This work has been done to understand the influence of the structure of package, the properties of underfill, the properties and thickness of bismaleimide tiazine substrate and the temperature range of thermal cycling on 2nd level solder joint reliability. The increase of bismaleimide tiazine substrate thickness applied to low modulus underfill was improve of solder joint reliability. The resistance of solder ball fatigue was increased solder ball size in the solder joints of FC-BGA.
A Study on the Feasibility of Partial Penetration Laser Welding for the Lap Joint of 390MPa High Strength Steel Sheets
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 95~101
After high power lasers are avaliable in the commercial market, the number of applications of the laser welding has been increased in manufacturing industries. Although the tailored blank laser welding of butt jointed steel sheets is well known recently in the automotive industries, the lap joint laser welding is a new technology to the automotive manufacturing people as well as the design people. But the deep penetration laser welding seems to be preferred to the partial penetration welding for the lap joint welding in the automotive manufacturers because the partial penetration is a serious deflect for the butt joint. In this study, the feasibility of partial penetration welding fur the lap joint
laser welding was studied fur the 1mm thick 390MPa high strength steel sheets for automotive bodies. The process window of the lap joint partial penetration welding was obtained from experiments with the gap size and the welding speed as process parameters. The partial penetration welding was found excellent on the basis of the tensile shear strength and sectional geometry. The bead width, input energy Per volume, tensile-shear strength, deformation energy and the sectional geometries after tensile-shear tests of partial penetration welded specimens are compared with those of full penetration welded specimens with a series of gaps and welding speeds.
Parameter Design and Analysis for Aluminum Resistance Spot Welding
Cho, Yong-Joon ; Li, Wei ; Hu, S. Jack ;
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 102~108
Resistance spot welding of aluminum alloys is based upon Joule heating of the components by passing a large current in a short duration. Since aluminum alloys have the potential to replace steels fur automobile body assemblies, it is important to study the process robustness of aluminum spot welding process. In order to evaluate the effects of process parameters on the weld quality, major process variables and abnormal process conditions were selected and analyzed. A newly developed two-stage, sliding-level experiment was adopted fur effective parameter design and analysis. Suitable ranges of welding current and button diameters were obtained through the experiment. The effects of the factors and their levels on the variation of acceptable welding current were considered in terms of main effects. From the results, it is concluded that any abnormal process condition decreases the suitable current range in the weld lobe curve. Pareto analysis of variance was also introduced to estimate the significant factors on the signal-to-noise (S/N) ratio. Among the six factors studied, fit-up condition is found to be the most significant factor influencing the SM ratio. Using a Pareto diagram, the optimal condition is determined and the SM ratio is significantly improved using the optimal condition.
Properties of Plasma Sprayed
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 109~115
In the case of using high temperature by coating ceramic/metal, large stress was produced due to difference of thermal expansion coefficient between those. And then lead to delamination. In order to relaxation of the stress A1
/SS316 composite powders with
compositional gradient and
agglomerated powder were made by spray drying method. These powders were sintered to improve the strength and to be plasma sprayed in order to fabricate the FGC(functionally graded coating). The influence of gun power, working distance and Ar pressure on the microstructure of the coating layer was studied in order to optimize the plasma spray conditions. It was proven that the optimum conditions were 40kw gun power, 5cm working distance and
Ar flow for both powders. FGC with 10 compositional steps was fabricated and the total thickness was 1.3mm. FGC was heat treated at
for 10hours to evaluate the heat resisting characteristics.
Fatigue Life Prediction for Resistance Spot Weldment of Aluminum Alloy Sheet
Journal of Welding and Joining, volume 20, issue 2, 2002, Pages 116~124
The fatigue life is predicted on tensile-shear spot weldment made from Al-Mg alloy sheet with thickness of 0.8mm using Mitchell's method and uniform material law by
and Seeger based on local strain approach. The fatigue properties of critical HAZ region are estimated from the tensile property using simple hardness method. To predict the fatigue life of spot weldment, the local stresses and strains at the potential critical region are estimated by Neuber's rule. The predicted fatigue life based on uniform material law using HAZ's material properties provides good results within a factor of 3, conservatively.