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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 19, Issue 6 - Dec 2001
Volume 19, Issue 5 - Oct 2001
Volume 19, Issue 4 - Aug 2001
Volume 19, Issue 3 - Jun 2001
Volume 19, Issue 2 - Apr 2001
Volume 19, Issue 1 - Feb 2001
Selecting the target year
The Effects of Root Gap on Mechanical Properties and Fatigue Strength of Weldment
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 98~103
Root gap out of standard by welding deformation is frequently produced at butt weld joints of steel bridge. For example although standard root gap is below 6mm at butt weld joints of plates under 15mm thickness. maximum 35mm root opening is produced at the weld field. At this case, the part out of standard is generally built up and the rest part is welded by WPS. Direct welding without built-up welding is preferred in weld field because built-up welding process bring about the cost-up at manufacturing. To apply this direct weld to root gap out of standard, the investigation about mechanical properties and fatigue at weldment is required. Inthisstudy, therefore the verification for direct weld without built up is performed at weldment as root gap. It includes tension, bending. hardness, impact and fatigue test for each welding specimen of 6mm, 25mm, 35mm root gap.
Fundamental of Fusion Welding - Shielding Gases for Arc Welding -
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 138~141
Arc and Laser Welding of Al Alloys for the Transportation Applications
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 142~150
Resistance Welding and Resistance Joining Technology to Fe-base Material of Al-alloy
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 151~159
Application of Friction Stir Welding to Aluminium Alloys
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 160~166
A Review on the Fracture Toughness Testing Method for Steel Weldment
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 167~175
Reflow Soldering Characteristics of Sn-3.5Ag Balls for BGA
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 176~181
Reflow soldering characteristics of Sn-3.5Ag and Sn-37Pb balls for BGA(Ball grid Array) were investigated. Diameter of 0.76mm ball was set on a Cu/Ni/Au-coated pad and reflowed in air with changing peak soldering temperature and conveyor speed. Peak temperatures were changed from 240 to 28
for Sn-3.5Ag, and from 220 to 26
for Sn-37Pb balls. As results, heights of solder balls increased and widths decreased with peak soldering temperature. Through aging treatment at 10
for 1.000 hrs, average hardness of Sn-3.5Ag balls bonded at 25
cecreased from 14.90Hv to 12.83Hv And with same aging conditions, average shear strength of Sn-3.5Ag balls bonded at 26
decreased from 1727gf to 1650gf.
A Study of Hydrogen Embrittlement Limit Potential of Cu-Containing High Strength Low Alloy Steel for Marine Structure by Potentiostatic SSRT Method
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 182~190
A marine structural material was well known to have high tensile strength, good weldability and proper corrosion resistance. Cu-containing high strength low alloy(HSLA) steel was recently developed for their purposes mentioned above. And the steel is free about preheating for welding, therefore it is reported that shipbuilding cost by using it can be saved more or less. However the marine structural materials like Cu-containing HSLA steel are being generally adopted with cathodic protection method in severe corrosive environment like natural sea water but the high strength steel may give rise to Hydrogen Embrittlement due to over protection at high cathodic current density for cathodic protection. In this study Cu-containing HSLA steel using well for marine atructure was investigated about the susceptibility of Hydrogen Embrittlement as functions of tensile strength, strain ratio, fracture time, and fracture mode, etc. and an optimum cathodic protection potential by slow strain rate test(SSRT) method as well as corrosion properties in natural sea water. And its corrosion resistance was superior to SS400 steel, but Hydrogen Embrittlement susceptibility of Cu-containing HSLA steel was higer than that of SS400 steel. However Hydrogen Embrittlement of its steel by SSRT method was showed with pheonomena such as decreasing of fracture time, strain ratio and fracture mode of QC(quasi-cleavage). Eventually it is suggested that an optimum cathodic protection potential not presenting Hydrogen Embrittlement of Cu-containing of HSLA steel by SSRT method was from-770mv(SCE) to - 900mV(SCE)under natural sea water.
A Study on the Optimum Bonding Preparation Condition of Single Crystal Superalloy
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 191~199
The oxidation and recrystallization behaviors of Ni-base single crystal superalloy, CMSX-2 were investigated to determine the condition of the preparation for transient liquid phase (TLP) bonding operations. The faying surfaces of CMSX-2 were worked by the shot peening, fine cutting and mechanical polishing treatments and the degree of working of treated surfaces was evaluated by the hardness test and X-ray diffraction method CMSX-2 was heat-treated at 1,173∼1.589k for 3.6ks in vacuum of 4mPa. The mechanically polished surface was slightly oxidized after heat treatment even in the vacuum atmosphere of 4mPa. The thickness of an oxide film increased with increasing the heating temperature and the surface roughness of the faying surface. Recrystallization occurred at the surface after heat treatment at above 1,423K when the hardness was increased more than Hv600 by the shot peening treatment while the mechanically polished or fine cut surfaces didn't recrystallized. Based on these results, it was clearfied that the mechanically polishing with fine abrasive grit could be used for the preparation of faying surface of CMSX-2 before bonding operation.
Measurement of GMAW Bead Geometry Using Biprism Stereo Vision Sensor
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 200~207
Three-diemnsional bead profile was measured using the biprism stereo vision sensor in GMAW, which consists of an optical filter, biprism and CCD camera. Since single CCD camera is used, this system has various advantages over the conventional stereo vision system using two cameras such as finding the corresponding points along the horizontal scanline. In this wort, the biprism stereo vision sensor was designed for the GMAW, and the linear calibration method was proposed to determine the prism and camera parameters. Image processing techniques were employed to find the corresponding point along the pool boundary. The ism-intensity contour corresponding to the pool boundary was found in the pixel order and the filter-based matching algorithm was used to refine the corresponding points in the subpixel order. Predicted bead dimensions were in broad agreements with the measured results under the conditions of spray mode and humping bead.
A Study on a Visual Sensor System for Weld Seam Tracking in Robotic GMA Welding
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 208~214
In this study, we constructed a visual sensor system for weld seam tracking in real time in GMA welding. A sensor part consists of a CCD camera, a band-pass filter, a diode laser system with a cylindrical lens, and a vision board for inter frame process. We used a commercialized robot system which includes a GMA welding machine. To extract the weld seam we used a inter frame process in vision board from that we could remove the noise due to the spatters and fume in the image. Since the image was very reasonable by using the inter frame p개cess, we could use the simplest way to extract the weld seam from the image, such as first differential and central difference method. Also we used a moving average method to the successive position data or weld seam for reducing the data fluctuation. In experiment the developed robot system with visual sensor could be able to track a most popular weld seam. such as a fillet-joint, a V-groove, and a lap-joint of which weld seam include planar and height directional variation.
Stress Analysis of Double T-Welded Joints Considering External Forces
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 215~220
In the T-joint welding, the complete penetration joint which is obtained by groove welding with edge preparation is generally required thor the safety and reliability of structures but this way have the some defects such as increase of working time, consumed welding electrode quantity and large welding deformation. If there is no probrem, in the strength, T-joint welding without edge preparation will be profitably understood in the economical and welding deformation side. In this paper, we performed the finite element analysis to understand the characteristics of welding residual stresses on two models, complete penetration joint have the edge preparation and incomplete penetration joint without edge preparation, respectively. Especially, we observed the relation between welding residual stress distributed on the notch of gap in the root and external force in the incomplete penetration joint without edge preparation.
A Study on the Effect of the Thickness of Bond Coating on the Thermal Stresses of a Sprayed Thermal Barrier Coating
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 221~227
Based on the principle of complementary energy, an analytical method is developed which focuses on the end effects for determining thermal stress distributions in a three-layered beam. This method gives the stress distributions which completely satisfy the stress-free boundary conditions. A numerical example is given in order to verify this method. The results show that the present analytical solutions have the values of stress in excellent agreement with the solutions derived by other investigators. Using this method, the effects of the thickness of bond coat on the thermal stresses of a typical sprayed thermal barrier coating, which consists of IN738LC substrate, MCrAIY bond coat and ZrO
top coat, were investigated.
Sensitivity Analysis of Processing Parameters for the Laser Surface Hardening Treatment by Using the Finite Element Method
Journal of Welding and Joining, volume 19, issue 2, 2001, Pages 228~234
A methodology is developed and used to evaluate the response sensitivity of the thermal systems to variations in their design parameters. Technique for computing the sensitivity of temperature distributions to changes in processing parameters needed to decide the more effective laser input parameters for laser surface hardening treatment is considered. In this study, a state equation governing the heat flow in laser surface treatment is analyzed using a three-dimensional finite element method and sensitivity data of the processing parameter obtained using a direct differentiation method is applied to the sensitivity analysis. The interesting processing parameters are taken as the laser scan velocity and laser beam radius (
), and the sensitivities of the temperature T versus v and
are analyzed. These sensitivity results are obtained with another parameters fixed. To verify the numerical analysis results, hardened layer dimensions (width and depth) of the numerical analysis are compared with the experimental ones.nes.