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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 32, Issue 6 - Dec 2014
Volume 32, Issue 5 - Oct 2014
Volume 32, Issue 4 - Aug 2014
Volume 32, Issue 3 - Jun 2014
Volume 32, Issue 2 - Apr 2014
Volume 32, Issue 1 - Feb 2014
Selecting the target year
Numerical Studies on Submerged Arc Welding Process
Kiran, Degala Ventaka ; Na, Suck-Joo ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 1~9
DOI : 10.5781/JWJ.2014.32.4.1
A quantitative understanding on the effect of the welding conditions on weld joint dimensions and weld thermal cycle is difficult through experimental studies alone. The experimental realization of temperature distribution in the weld pool is proved to be extremely difficult due to the small size of welds, high peak temperature and steep temperature gradients in weld pool. This review deals with the heat transfer and fluid flow analysis to understand the parametric influence of a single wire submerged arc welding (SAW) and multi-wire SAW processes on the weld bead dimensions, temperature and fluid flow distribution in the weldment.
Effects and Application Cases of Injection Molds by using DED type Additive Manufacturing Process
Kim, Woosung ; Hong, Myungpyo ; Kim, Yanggon ; Suh, Chang Hee ; Lee, Jongwon ; Lee, Sunghee ; Sung, Ji Hyun ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 10~14
DOI : 10.5781/JWJ.2014.32.4.10
Laser aided Direct Metal Tooling(DMT) process is a kind of Additive Manufacturing processes (or 3D-Printing processes), which is developed for using various commercial steel powders such as P20, P21, SUS420, H13, D2 and other non-ferrous metal powders, aluminum alloys, titanium alloys, copper alloys and so on. The DMT process is a versatile process which can be applied to various fields like the mold industry, the medical industry, and the defense industry. Among of them, the application of DMT process to the mold industry is one of the most attractive and practical applications since the conformal cooling channel core of injection molds can be fabricated at the slightly expensive cost by using the hybrid fabrication method of DMT technology compared to the part fabricated with the machining technology. The main objectives of this study are to provide various characteristics of the parts made by DMT process compared to the same parts machined from bulk materials and prove the performance of the injection mold equipped with the conformal cooling channel core which is fabricated by the hybrid method of DMT process.
Laser Additive Manufacturing Technology Review
Hwang, Myun Joong ; Cho, Jungho ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 15~19
DOI : 10.5781/JWJ.2014.32.4.15
Additive manufacturing technology is taking great attentions in these days because the term 3D-printing became a hot issue as the next generation manufacturing paradigm. Especially, laser additive manufacturing is at the center of interest thanks to the accuracy compared to other heat sources. In this report, recent papers about laser additive manufacturing are analyzed and reviewed. General technology is specified into three different categories and they are laser sintering, laser melting and laser metal deposition. Similarities and differences are clearly described by detailed technologies and used materials type. Representative application examples are selected then future of this technology is expected through those applications. Additionally, market of laser additive manufacturing systems itself and application fields are also predicted based on present 3D-printing market and technical progressions.
A Study on Joining of 3D Thermoset and Biodegradable Polymers
Yoon, Sung Chul ; Ma, Jae Kwon ; Bang, Dae Wook ; Choi, Hae Woon ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 20~25
DOI : 10.5781/JWJ.2014.32.4.20
Laser heat source was applied on 3D poly urethane model built by 3D printer and cellulous acetate for joining. A diode laser with 808nm wavelength was transmitted through the 3D model and applied on the boundary of ABS/Acetate and 3D poly urethane model. Based on the experimental result, the ABS and 3D built poly-urethane polymers was successfully joined, but the mechanical strength was not enough at the joining boundaries in the range of 6watt to 8watt of laser heat source. However, biodegradable acetate was successfully joined without damaging the 3D built model and mechanical strength was properly achieved. The optimum laser power was found between 5watt and 8watt with scanning speed of 500mm/min, 700mm/min and 1,000mm/min. Based on the SEM analysis the filling mechanism was that the applied pressure on 3D built model squeezed the fluidic thermoplastics, ABS and acetate, into the structure of 3D model. Therefore soundness of joining was strongly depending on the viscosity of thermoplastics in polymers. The developed laser process is expected to increase productivity and minimize the cost for the final products.
A Study on Characteristics of Dissimilar Welds between Super Duplex Stainless Steel UNS S32750 and Carbon Steel A516-70 with FCAW
Moon, In-June ; Jang, Bok-Su ; Kim, Se-Cheol ; Koh, Jin-Hyun ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 26~33
DOI : 10.5781/JWJ.2014.32.4.26
The metallurgical and mechanical characteristics, toughness and corrosion resistance of dissimilar welds between super duplex stainless steel UNS S32750 and carbon steel ASTM A516Gr.70 have been evaluated. Three heat inputs of 21.12, 24.00, 26.88kJ/cm were employed to make joints of dissimilar metals with flux cored arc welding(FCAW). Based on microstructural examination, vermicular ferrite was formed in the first layer of weld at low heat input(21.12kJ/cm) and
of 1.61 while acicular ferrite was formed in last layer of weld at high heat input(26.88kJ/cm) and
of 1.72. Ferrite percentage in dissimilar welds was lowest in the first layer of weld regardless of heat inputs and it gradually increased in the second and third layers of weld. Heat affected zone showed higher hardness than the weld metal although reheated zone showed lower hardness than weld metal due to the formation of secondary austenite. Tensile strengths of dissimilar welds increased with heat input and there was 100MPa difference. The corrosion test by ferric chloride solution showed that carbon steel had poor corrosion resistance and pitting corrosion occurred in the first layer(root pass) of weld due to the presence of reheated zone where secondary austenite was formed. The salt spray test of carbon steel showed that the surface only corroded but the amount of weight loss was extremely low.
The Effect of Fatigue Strength according to Carburizing Depth
Choi, Hyun Min ; Park, Yong Ha ; Shin, Yong Taek ; Kim, Myung Hyun ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 34~38
DOI : 10.5781/JWJ.2014.32.4.34
Carburizing treatments are the important way to developing fatigue strength and wear resistance. It is well known that the case depth is one of the most significant parameters determining fatigue strength. In this study, 3-point bending fatigue test was conducted to evaluate fatigue strength for the carburized depth with 18CrNiMo7-6 steel. As a result, fatigue strength increased with effective case depth decreased. It is shown that hardness in case hardened layer played principal role in the fatigue strength.
The Training Methods and Effectiveness using Augmented Reality Contents System for Machine Drawings Training Which is Essential in Welding Practice Courses
Koo, Chang-Dae ; Yang, Hyeong-Seok ; Lee, Dong-Youp ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 39~45
DOI : 10.5781/JWJ.2014.32.4.39
Today, the development of digitized information media and info-communications are bringing many changes. Due to the development of IT thechnology, we can learn wherever, whenever, regardless of time and place. Machine drawing subject is a very important in mechanical engineering course, but it's studyed only basic theory in a short period, average 1~2weeks. So that, students think that the mechanical drawing is of minor importance. Such ideas make them difficult to impove sense of space in isometric drawing and drawing skill. Therefore, in this paper, augmented reality-based contents through the system, Mechanical Drawing of education to meet the effectiveness and satisfaction, student learning can be spontaneously it was construct self-system. And, Theoretical part of the Mechanical Drawing is proposed ensure more efficient and easier training. In this paper, we were test operation for user effectualness of proposed service at Korea Polytechnics Colleges a industrial facilities management in Daegu. Target user are 66 students, and The students were divided into experimental group and comparison group. Experimental results, experimental group was able to do systematically experience many Projection Drawing and Pictorial Drawing in short schooltime. And, The test operation results showed that have the possibility to meet education effectiveness and user satisfaction in this augmented reality-based contents system.
Effect of Bonding Temperature and Bonding Pressure on Deformation and Tensile Properties of Diffusion Bonded Joint of STS304 Compact Heat Exchanger
Jeon, Ae-Jeong ; Yoon, Tae-Jin ; Kim, Sang-Ho ; Kim, Hyeon-Jun ; Kang, Chung-Yun ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 46~54
DOI : 10.5781/JWJ.2014.32.4.46
In this study, the effect of bonding temperature and bonding pressure on deformation and tensile properties of diffusion bonded joint of STS304 compact heat exchanger was investigated. The diffusion bonds were prepared at 700, 800 and
for 30, 60 and 90 min in pressure of 3, 5, and 7 MPa under high vacuum condition. The height deformation of joint decreased and the width deformation of joint increased with increasing bonding pressure at
. The ratio of non-bonded layer and void observed in the joint decreased with increasing bonding temperature and bonding pressure. Three types of the fracture surface were observed after tensile test. The non-bonded layer was observed in diffusion bonded joint preformed at
, the non-bonded layer and void were observed at
. On the other hand, the ductile fracture occurred in diffusion bonded joint preformed at
. Tensile load of joint bonded at
was proportional to length of bonded layer and tensile load of joint bonded at
was proportional to minimum width of pattern. The tensile strength of joint was same as base metal.
Corrosion Assessment of Al/Fe Dissimilar Metal Joint
Kang, Minjung ; Kim, Cheolhee ; Kim, Junki ; Kim, Dongcheol ; Kim, Jonghoon ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 55~62
DOI : 10.5781/JWJ.2014.32.4.55
The use of light-weight Al alloys in the automotive industry is increasing to meet requirements for fuel efficiency and emission reduction. Joining Al alloy to the conventional steel sheet is also very important issue with the increased use of Al alloy, and several joining processes have been introduced to enhance joining strength between dissimilar metals. This paper deals with a galvanic corrosion in the dissimilar metal joining. Salt spray tests up to 2000 hours were conducted on a self-piercing rivet, spot welded, adhesive bonded and weld-bonded joints, and cross-sections and tensile shear strength according the salt spray duration were analyzed at every 500-hour. Self-piercing rivet joint had relative low initial strength but the joint strength did not change regardless of the salt spray duration. The strength of other joints (spot welded, adhesive bonded and weld-bonded joints) decreased with the increase of salt spray duration and the corrosion behaviour of each joint was discussed.
Effects of PWHT on Tensile Properties and Impact Toughness of FCAW Weld Metal of FH Steels for Cargo Tank in LPG Carrier
Jeong, Sang-Hoon ; Kang, Chang-Yong ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 63~68
DOI : 10.5781/JWJ.2014.32.4.63
This paper has an aim to study the effect of PWHT and its conditions(peak temperature and holding time) on the tensile properties and impact toughness of FCAW weld metal in relation to microstructure. Impact toughness was evaluated to apply the cargo tank of liquified gas carriers under the various PWHT condition of each class societies. On the basis of these study, it was found that PWHT conditions within all class societies affect charpy absorbed energy of weld metal little or no, all PWHT weld metals kept similar level of charpy absorbed energy as as-weld weld metal down-to
and finally indicated lower energy value than that of as-weld weld metal at
. It is because the precipitation of 2nd phase was controlled from welding consumable and the grain size was grown by PWHT.
Analysis of Welding Distortion of Large Steel Plate by Using Analytical Solution of Temperature Distribution and Finite Element Method
Hong, Sung-Bin ; Bae, Kang-Yul ; Yang, Young-Soo ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 69~74
DOI : 10.5781/JWJ.2014.32.4.69
Welding distortions of large steel structures had mainly been estimated with some simplified formula obtained by lots of experience and numerical analyses for small steel structures. However, the large structures would have different characteristics of distortion with welding because of their own stiffness coming from the size itself. Therefore, in order to find some measures for preventing welding distortion of large structure, it is requite in advance to precisely analysis thermal stress and distortion during welding of the structure. Numerical analysis for larger structure has been known to take large amount of calculation time and have a poor convergency problem during the thermo-elasto-plastic calculation. In this study, a hybrid method is proposed to analysis the thermal stress and distortion of a large steel plate with the finite element analysis by incorporating with temperature distribution of the plate calculated by an analytical solution. The proposed method revealed that the thermo-mechanical analysis for welding of the large structure could be performed with a good convergence and produced precise results with much reduced time consumption.
Effects of PWHT on Weld Metal Properties of YS 460 MPa Steels for Ship and Offshore Structures
Kang, Chang-Yong ; Jeong, Sang-Hoon ;
Journal of Welding and Joining, volume 32, issue 4, 2014, Pages 75~79
DOI : 10.5781/JWJ.2014.32.4.75
This paper has an aim to study the effect of PWHT(for 140min. at
) on FCAW weld metal properties (tensile, charpy impact and CTOD value) of YS 460 MPa steels for ship and offshore structures. On the basis of these study, it was found that strength was decreased and elongation was increased by PWHT. These phenomenon resulted from the reduction of acicula ferrite volume fraction by grain growth. Also, Charpy impact and CTOD value were decreased by PWHT. These phenomenon resulted from grain growth. Because the grain boundary grown by PWHT can play a role as crack initiation site and make the crack propagate more easily. Although weld metal properties were decreased by PWHT, tensile and impact properties could meet the class societies requirements for welds of YS 460 MPa steel, but decrease of fracture toughness need to be consider seriously.