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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 30, Issue 6 - Dec 2012
Volume 30, Issue 5 - Oct 2012
Volume 30, Issue 4 - Aug 2012
Volume 30, Issue 3 - Jun 2012
Volume 30, Issue 2 - Apr 2012
Volume 30, Issue 1 - Feb 2012
Selecting the target year
Joint Reliability of Sn3.5Ag, Sn0.7Cu and Sn5.0Sb Pb-free Solder and Hybrids Joining Process for Application of Automobile Electric Module
Kang, Myong-Suk ; Bang, Jung-Hwan ; Lee, Chang-Woo ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 1~5
DOI : 10.5781/KWJS.2012.30.6.487
Evaluation HIC Crack Resistance for Plastic Deformation of API-X65 Plate
Ryoo, Hoi-Soo ; Seo, Jun Seok ; Kim, Hee-Jin ; Lee, Dong-Eon ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 6~9
DOI : 10.5781/KWJS.2012.30.6.492
A Welding Characteristics of Large Caliber-Thick Plate Pressure Vessel Low Alloy Steel (Mn-Mo)
Ahn, Jong-Seok ; Park, Jin-Keun ; Yoon, Jae-Yeon ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 10~14
DOI : 10.5781/KWJS.2012.30.6.496
Recently the low alloy steel plate made with manganese-molybdenum is used widely in steam drum and separator of the new coal-fired power plant boiler. This material is suitable for the vapor storage of high pressure and high temperature. The high temperature creep strength of Mn-Mo alloy is higher than the carbon plate(SA516) that used in the subcritical pressure boiler. It reduces the thickness of the pressure vessel and makes the lightweight possible. Recently in the power plant boiler operation and production process, the damage has happened frequently in the heat affected zone and base material according to the hydrogen crack and delayed crack. This paper describes the research result about the damage case experienced in the boiler steam drum production process and present the optimum manufacture method for the similar damage prevention of recurrence.
Brazing Filler Metal and Process for Stainless Steel
Hong, Sung Chul ; Park, Sang Yoon ; Jung, Do Hyun ; Oh, Joo Hee ; Lee, Jae Hoon ; Kim, Wonjoong ; Jung, Jae Pil ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 15~20
DOI : 10.5781/KWJS.2012.30.6.501
Brazing technology has been widely used among bonding technologies because it enables to bond various metals, even ceramics, dissimilar metals, and give higher bonding strength, cost down, automation, etc. However, there are many parameters to achieve optimal brazing joint such as brazing alloys, brazing atmospheres, designs and brazing methods, etc. The brazing parameters affect seriously on the characteristic of final brazing products. Stainless steel is broadly used in high temperature applications, chemical industry, heat exchangers, muffler of vehicles, and so on. Accordingly, in this article, brazing alloys, forms of brazing alloys, brazing methods and atmospheres for stainless steel were described.
Trend on Research TLP Bonding of Ni and Ni Base Superalloy for High Temperature Heat Exchanger
Kang, Chung-Yun ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 21~26
DOI : 10.5781/KWJS.2012.30.6.507
Recent Study of TiAl Brazing
Yoo, Ho-Cheon ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 27~35
DOI : 10.5781/KWJS.2012.30.6.513
A Technique for Defect Detection of Condenser Tube in Support Plate Region using Guided Wave
Kim, Yong-Kwon ; Park, Ik-Keun ; Park, Sae-Jun ; Ahn, Yeon-Shik ; Gil, Doo-Song ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 36~41
DOI : 10.5781/KWJS.2012.30.6.522
General condensers consist of many tubes supported by tube sheets and support plates to prevent the deflection of the condenser tubes. When a fluid at high pressure and temperature runs over the tubes for the purpose of transferring heat from one medium to another, the tubes vibrate and their surface comes into contact with the support plates. This vibration causes damage to the tubes, such as cracks and wear. We propose an ultrasonic guided wave technique to detect the above problems in the support plate region. In the proposed method, the ultrasonic guided wave mode, L(0,1), is excited using an internal transducer probe from a single position at the end of the tube. In this paper, we present a preliminary experimental verification using a super stainless tube and show that the defects can be discriminated from the support signals in the support region.
A Experiment Study on Selection the Optimal Condition for GMA Root-pass Welding in Overhead and Vertical Position
Kim, Ji-Sun ; Kim, In-Ju ; Kim, Ill-Soo ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 42~48
DOI : 10.5781/KWJS.2012.30.6.528
Due to increase in demand of stable and long pipelines in natural gas industry, wide range of researches are being performed on automation welding to improved welding quality with respect to weld process parameters in real time measurement. In particular, the coupling between the pipe manufacturing process and location of the weld seam, the measured size of the gap that exists in the weld position and the weld angle depending on whether the movement of molten weld. This is due to absence of controlling welding penetration position, depending on the required size of the angle of the setting. In addition, the optimum welding conditions must be considered while selecting, the correlation between these variables and the systematic correlation has not yet been identified. Therefore, in most welded pipe root-pass weld solely depends on the experience of workers in relation to secure a stable weld quality. In this study, automation welding system is implemented to select a suitable root-pass STT (Surface Tension Transfer) welding method using the optimal welding conditions. To successfully accomplish this objective, there were various welding conditions used for welding experiment to confirm that the assessment required for construction through the pipe and automatic welding process is proposed to optimize this plan.
A Experiment Study of Torch Distance on Automated Tandem GMA Welding System
Lee, Ji-Hye ; Kim, Ill-Soo ; Jung, Seong-Myeong ; Lee, Jong-Pyo ; Kim, Young-Su ; Park, Min-Ho ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 49~55
DOI : 10.5781/KWJS.2012.30.6.535
The tandem welding process is one of the most efficient welding processes widely used in material joining technique such as manufacturing of strong and durable structures. It facilitates high rate of joint filling with little increase in the overall rate of heat input due to the simultaneous deposition from two electrode wires. The two electrodes in tandem welding process helps in high-efficiency and high productive of welding process. In this study a automated tandem welding system is developed to determine the correlation between cathode and anode and compared with current ratio of the two electrode torch. Three different inter-electrode distances were chosen, 25mm, 35mm and 45mm to perform the experiment with three different current ratio. From the experiment results, the current ratio between two torch has a large impact on width, height and depth of penetration. In addition, a stable bead geometry is obtained when inter-electrode distance is 35mm.
A Study on the Weldability of Magnesium Alloy by Laser Heat Source (II) - Mechanical Properties of laser-welded AZ31B-H24 and AZ31B-O -
Lee, Jung-Han ; Kim, Jong-Do ; Lee, Mun-Yong ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 56~61
DOI : 10.5781/KWJS.2012.30.6.542
Magnesium alloy sheet which is commercially available in the market presently is AZ31B, a Mg-Al-Zn three elements alloy. AZ31B is used by being classified into AZ31B-H24 and AZ31B-O depending on temper designation. In this study, AZ31B-H24 and AZ31B-O alloy sheets with 1.25mm thickness were butt-welded using CW Nd:YAG laser. And the effect of materials on mechanical properties was investigated by tensile and hardness tests. As a result of this study, regardless of materials, the butt-welded joint did not show a significant difference in tensile strength and hardness values. However, compared with the basemetal, the AZ31B-O showed more outstanding mechanical properties than AZ31B-H24, and that is because H24 material lost the effect of work hardening during welding.
Experimental Study on Evaluation of Bonding Strength of Adhesively Bonded Joints by Adhesive
Kang, Ki-Yeob ; Lee, Jae-Myung ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 62~67
DOI : 10.5781/KWJS.2012.30.6.548
In this study, the bonding strengths of adhesively bonded joints are experimentally investigated. A series of lap-shear tests are conducted using single lap type adhesive joints. In order to analyse the joint fabrication factors that affected the bonding strength, the parametric tests are conducted with various thickness of adhesive, surface roughness and fillet of adhesive. In addition, for the comparative study with the welded joint, lap-shear tests using specimens with 2 welded sides and 4 welded sides are also carried out. The quantitative results of the strength analysis are summarized, and some proposals are made on setting up testing standards for adhesively bonded joints.
Lobe Curve Characteristic Analysis of Resistance Spot Welding for Sheet Combination of 780MPa Steel Sheet Using Simulation
Son, Chang-Seok ; Park, Young Whan ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 68~73
DOI : 10.5781/KWJS.2012.30.6.554
Nowadays, car manufacturers tried to improve automotive fuel efficiency, and applied many high strength steels such as AHSS or UHSS to car bodies. Therefore, the number of steel combinations for the resistance spot welding are dramatically increased and the need for weldability evaluation of these combinations are also required. In this study, we suggest the lobe curve using FEM simulations for DP780 steel with 1.0t, 1.4t. The lobe curves which could expressed weldablity and optimal welding condition were obtained according to 6 steel combinations. There were two combinations for same steel sheet which were DP780 1.0t, DP780 1.4t. Dissimilar steel sheet combination with different thickness was 1.0t and 1.4t of DP780. Different steel combinations were DP780 1.0t and SPRC440 1.0t, and DP780 1.0t and DP590 1.0t. Finally dissimilar combinations was and DP780 1.0t and DP590 1.4t. The trend of low boundary and high boundary variation of lobe curve were analyzed with a viewpoint of the contact resistance and the heat input.
Residual Stress Prediction in Multi-layer Butt Weld Using Crack Compliance Method
Kim, Yooil ; Lee, Jang Hyun ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 74~79
DOI : 10.5781/KWJS.2012.30.6.560
It depends on the joint configuration, dimensions and constraints of the joint whether the residual stress at the root of single-sided butt weld is tensile or not. Therefore, recommendation is generally made that high R ratio should be used in the fatigue test of welded joint in order to prevent excessively long life caused by compressive residual stress. In this research, the residual stress profile in butt weld joint was obtained through compliance method, using successive extension of a slot and measurement of the variation of strain during the slot extension. The residual stress profile was firstly assumed to be the linear summation of Legendre polynomials up to 9th order excluding 0th and 1st order. Strain variation on the surface was measured while the slot was being extended by cutting to find out the 8 unknown coefficients of each polynomial term. The cut was made by the electric discharge machine. It was concluded that the residual stress near the surface is positive valued, however, it turned into the negative value as soon as it passed through 2 or 3 mm of the depth.
A Study on the Measurement of Stress Intensity Factors for the Fatigue Crack Propagation
Oh, Dong-Jin ; Kim, Myung-Hyun ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 80~85
DOI : 10.5781/KWJS.2012.30.6.566
Fatigue cracks in structural components are the most common cause of structural failure when exposed to fatigue loading. In this respect, fatigue crack detection and structural health assessment are very important. Currently, various smart materials are used for detecting fatigue crack and measurement of SIFs(Stress Intensity Factors). So, this paper presented a measurement of SIFs using MFC(Micro Fiber Composite) sensor which is the one of the smart material. MFC sensor is more flexible, durable and reliable than other smart materials. The SIFs of Mode I(K I) as well as Mode II(K II) based on the piezoelectric constitutive law and fracture mechanics are calculated. In this study, the SIF values measured by MFC sensors are compared with the theoretical results.
Fatigue Assessment of Load-carrying Asymmetric Double Bevel Cruciform Welded Joints using Structural Stress Approach
Kim, Seong-Min ; Kim, Young-Nam ; Lee, Seung-Hyun ; Kim, Myung-Hyun ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 86~91
DOI : 10.5781/KWJS.2012.30.6.572
Fatigue tests and analyses were carried out to investigate fatigue strength and crack initiation point of load-carrying asymmetric double bevel cruciform welded joints. Mesh-insensitive structural stress approach was adopted to estimate high precise fatigue life and crack initiation point. Two different case material and weld shape were considered in this study. Results of fatigue tests and analyses were compared and discussed in consideration of applicability of structural stress approach as the reliable fatigue assessment method of cruciform welded joints.
Mechanical Properties and Fabrication of WC-Co Hard Materials by Rapid Sintering Method for Friction Stir Welding Tool Application
Park, Hyun-Kuk ; Youn, Hee-Jun ; Ryu, Jung-Han ; Jang, Jun-Ho ; Shon, In-Jin ; Oh, Ik-Hyun ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 92~97
DOI : 10.5781/KWJS.2012.30.6.578
Using the pulsed current activated sintering method, the WC-10wt.% Co materials were densified using a WC and Co powder. The WC-Co almost completely dense with a relative density of up to 99.5 % after the simultaneous application of a pressure of 60 MPa and an electric current for 3 minutes almost without any significant change in the grain size. The average grain size of about
. The hardness and fracture toughness at
Effect of Welding Condition on Tensile Properties of Friction Stir Lap Joint of Dissimilar Al Alloy, KS5J32/AA6K31
Kim, Sang-Ju ; Yoon, Tae-Jin ; Song, Sang-Woo ; Kang, Chung-Yun ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 98~105
DOI : 10.5781/KWJS.2012.30.6.584
The focus of this investigation is to evaluate the effect of joining parameter on the microstructure and mechanical properties of welds produced by friction stir lap welding. The dissimilar Al alloys, KS5J32 and AA6K31, were joined by friction stir lap welding technique under several welding conditions, and KS5J32 alloy was placed on the top of AA6K31 alloy. The tool rotation speeds were 1000, 1250, and 1500rpm, and the welding speeds were 100, 300, 500, 700mm/min, respectively. The results showed that two shapes of nugget, such as onion ring and irregular vortex type, were observed with various revolutionary pitch. In all welding conditions, fracture occurred at the soften region of bottom sheet(AA6K31) and the strengths were 64~78% of those of base metal. Fractured positions were classified into three types : HAZ, triple point, void depending on the revolutionary pitch. The actual thickness of specimen at the fractured location was decreased with decreasing heat input. A linear relationship exists between the effective thickness of fractured position and peak load.
Effect of Brazing Condition on Tensile Properties in Brazing Joints of Inconel-625/Ni-201 Using MBF-30
Yu, Jeong-Woo ; Park, Sang-Hyun ; Kim, Chang-Su ; Kang, Chung-Yun ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 106~112
DOI : 10.5781/KWJS.2012.30.6.592
This study was carried out to investigate the effect of bonding temperature and holding time on microstructure and mechanical properties in brazing joints of Ni-base superalloy using MBF-30 (Ni-4.5Si-3.2B [wt.%]). The heating rate was
/min to the bonding temperatures
under high vacuum condition. The holding times were 100s, 400s, 900s and 1600s.
phases and proeutectic Ni were observed in the interlayer of Ni-201. Then, Ni3B and Ni3Si were found in the middle region of brazing joint. Cr-boride phase appeared in the interlayer of Inconel-625. Tensile strength and elongation were decreased at
-400s. After observation the fracture specimens, There was Ni3B which is very brittle phase in the grain boundary of Ni201.
Design by Topology Optimization and Performance Test of Ultrasonic Bonding Module for Flip-Chip Packaging
Kim, Ji Soo ; Kim, Jong Min ; Lee, Soo Il ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 113~119
DOI : 10.5781/KWJS.2012.30.6.599
Ultrasonic bonding is the novel packaging method for flip-chip with high yield and low-temperature bonding. The bonding module is a core part of the bonding machine, which can transfer the ultrasonic energy into the bonding spot. In this paper, we propose topology optimization technique which can make new design of boding modules due to the constraints on resonance frequency and mode shapes. The designed bonding module using topology optimization was fabricated in order to evaluate the bonding performance and reliable operation during the continuous bonding process. The actual production models based on the proposed design satisfied the target frequency range and ultrasonic power. The bonding test was performed using flip-chip with lead-free Sn-based bumps, the results confirmed that the bonding strength was sufficient with the designed bonding modules. Also the performance degradation of the bonding module was not observed after the 300-hour continuous process with bonding conditions.
A Study on the Thermal Distortion Analysis of Welded Structures having K/X Groove using shell elements
Ha, Yunsok ; Choi, Jiwon ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 120~125
DOI : 10.5781/KWJS.2012.30.6.606
Because ships and offshore structures have very large dimensions and complicated shapes, it is difficult to determine the deformation or internal stress in the structure by simple lab tests. Thus, a rigorous analysis by using the computer simulation technology is essential for obtaining their distortions by considering the entire production process characteristics. The rapid development of computer technology made it possible to analyze the heat transfer phenomena, deformation and phase transformation in the welded joint. For large shell structures, shell elements modeling contributed primarily to this development. But if a welding is done by multi-pass, shell elements whose thickness are unchangeable can hard to describe the local situation. Recently, it was researched how to introduce the imaginary temperature for V grooved multi-layer butt welding in strain-boundary method (a kind of shrinkage methodologies). In the present study, we formulated the imaginary temperature for the double bevel and double V groove by considering the thickness change of each pass through the bead and the thickness directions simultaneously and also demonstrated the feasibility of the formula by applying it to the thermal distortion analysis of the erection process of crane pedestal.
A Study on Bead Geometry Prediction the GMA Fillet Welding using Genetic Algorithm
Kim, Young-Su ; Kim, Ill-Soo ; Lee, Ji-Hye ; Jung, Sung-Myoung ; Lee, Jong-Pyo ; Park, Min-Ho ; Chand, Reenal Ritesh ;
Journal of Welding and Joining, volume 30, issue 6, 2012, Pages 126~132
DOI : 10.5781/KWJS.2012.30.6.612
The GMA welding process involves large number of interdependent variables which may affect product quality, productivity and cost effectiveness. The relationships between process parameters for a fillet joint and bead geometry are complex because a number of process parameters are involved. To make the automated GMA welding, a method that predicts bead geometry and accomplishes the desired mechanical properties of the weldment should be developed. The developed method should also cover a wide range of material thicknesses and be applicable for all welding position. For the automatic welding system, the data must be available in the form of mathematical equations. In this study a new intelligent model with genetic algorithm has been proposed to investigate interrelationships between welding parameters and bead geometry for the automated GMA welding process. Through the developed model, the correlation between process parameters and bead geometry obtained from the actual experimental results, predicts that data did not show much of a difference, which means that it is quite suitable for the developed genetic algorithm. Progress to be able to control the process parameters in order to obtain the desired bead shape, as well as the systematic study of the genetic algorithm was developed on the basis of the data obtained through the experiments in this study can be applied. In addition, the developed genetic algorithm has the ability to predict the bead shape of the experimental results with satisfactory accuracy.