• Title/Summary/Keyword: Deposited Metal

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Prediction of Weld Penetration and Deposited Metal Area in Accordance with Weld Parameters in Tandem Submerged Arc Welding Process (탄뎀 서브머지드 용접 공법의 용접조건에 따른 용입깊이 및 용착면적 예측)

  • Park, Se-Jin;Nam, Seong-Kil;Kweon, Chang-Gil
    • Journal of Welding and Joining
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    • v.29 no.6
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    • pp.71-76
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    • 2011
  • Submerged arc welding method from both sides is generally applied to the welding of main panel manufacturing process during ship construction. The tandem SAW method is applied to improve the productivity. The various weld defects that occur during tandem SAW method are melt through, incomplete penetration, undercut and overlap etc. It could be thought that the reasons for these defects are mainly lack of prediction ability for penetration depth and deposited metal area. In this research, total 5 kinds of welding factors for experiment like current of lead pole, voltage of lead pole, current of trail pole, voltage of trail pole and welding speed are adopted. Weld tests are carried out for the analysis of variation effects of these factors on penetration depth and deposited metal area. Based on the test and analysis results, it is possible to obtain the prediction equation for the effect of these factors on the amount of deposited metal and penetration depth. As per the verification of the results by additional tests, it is confirmed that the prediction equation, include a error margin of ${\pm}2mm$ for penetration depth and ${\pm}10mm2$ for deposited metal area.

Characteristics of Fatigue Behavior and Fracture Surfaces by Rotary Bending Test in SM45C Welding Zone (SM45C용접부에서 회전굽힘시험에 의한 피로 및 파단면의 특성)

  • Lee, Yong-Bok
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.1
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    • pp.26-32
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    • 2010
  • SM45C steel rods using generally for machine components were selected and welded by butt-GMA welding method for this study. And then they were studied about characteristics of fatigue behavior and fracture surfaces by rotary bending test. Fatigue strength in weld zone present highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. The region of infinite life by Haigh diagram present highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. Fatigue cracks in unnotched specimens of base metal and weld zone introduce simultaneously from extensive out-side of circumferential cross-section and propagate to the other side indicating beach markings and dimples according to consolidation of fatigue cracks. Fatigue cracks in all of notched specimens introduce simultaneously in out-side of circumferential cross-section by high stresses and propagate to center of it indicating beach markings.

An Experimental Study on Fatigue Behavior in Welded SM45C Steel Rod (SM45C 환봉 용접재의 피로거동에 관한 실험적 연구)

  • Lee, Yong-Bok;Jung, Jae-Keun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.6
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    • pp.519-525
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    • 2008
  • For this study, SM45C steel rods using generally for power transmission shafts and machine components was selected and welded by butt-GMAW method. And then it was studied about estimation of fatigue strength and the region of infinite life by Haigh diagram using Goodman's equation. Fatigue strength in weld zone presents highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. This result agrees with distribution of hardness in weld zone. Fatigue strength in base metal zone presents highly compared with weld zone in low cycles between $10^4$ cycles and $10^6$cycles, but it presents the lowest fatigue strength on the order of heat affected zone in the vicinity of $10^6$cycles. It is the result that the first high compressive residual stress distributed by drawing process of the steel rods is released and the base metal is softened by alternating stresses. The region of infinite life by Haigh diagram presents highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. From this results, it is demanded that the stress for safety design of machine components using SM45C butt-welded steel rods must be selected in the region of the lowest infinite life of heat affected zone.

A Study on Fatigue Strength Characteristics of Weld Joint using Metal Type Flux Cored Wire (금속계 플럭스들이 용접이음부의 피로강도 특성에 관한 연구)

  • 강성원;신동진;김환식
    • Journal of Welding and Joining
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    • v.12 no.4
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    • pp.151-161
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    • 1994
  • FCAW has wide application in ship fabrication, maintenance and field erection. It has many advantages over SMAW.SAW and GMAW process. In many applications, the FCAW provides highquality weld metal. This method can reduce weld defects especially porosity and spatter. But the fatigue characteristics of those deposited metal have been rarely investigated. The purpose of this study is to investigate the cyclic stress-strain behavior and fatigue tests by the constant strain control were carried out on the rounded smooth specimen with deposited metal using the metal type flux cored wire. As the results of this study for the deposited metal welded by the metal type flux cored wire, the hardening or softening characteristics under cyclic load were investigated and cyclic stress-strain curve, strain-fatigue life curve, stress-strain function and fatigue life relation which are useful to estimate the fatigue life under the stress concentration condition were obtained.

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Effect of Sigma Phase on Electrochemical Corrosion Characteristics of a Deposited Metal of ER2594 (ER2594 용착금속의 전기화학적 부식특성에 미치는 시그마상의 영향)

  • Jung, Byong-Ho;Kim, Si-Young;Seo, Gi-Jeong;Park, Joo-Young
    • Journal of Power System Engineering
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    • v.19 no.6
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    • pp.75-81
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    • 2015
  • A deposited metal specimen of ER2594 which is a super duplex steel welding wire used to investigate the effect of sigma(${\sigma}$) phase on electrochemical corrosion characteristics was prepared by gas tungsten arc welding. Aging treatment was conducted for the specimen at the temperature range of $700^{\circ}C$ to $900^{\circ}C$ for 5 to 300 minutes after annealing at $1050^{\circ}C$. Corrosion current density has decreased a little with an increase of aging time over 60 minutes at $700^{\circ}C$ to $900^{\circ}C$ and the uniform corrosion of deposited metal had more influence on the precipitation of ferrite than the precipitation of sigma phase. Therefore, the precipitation of sigma phase did not have much effect on the uniform corrosion. Pitting potential representing pitting corrosion has shown decreasing tendency as the precipitation of sigma phase increased. The degree of sensitization representing intergranular corrosion has shown increasing tendency as the precipitation of sigma phase increased at $700^{\circ}C$ to $800^{\circ}C$, while it has decreased at $900^{\circ}C$ for 60 to 300 minutes.

Evaluation of Characteristics of Welding Zones Welded with Inconel 718 Filler Metal to Piston Crown Forged Material (피스톤 크라운용 단강에 인코넬 718 용접재료로 용접된 용접부의 특성 평가)

  • Lee, Sung-Yul;Moon, Kyung-Man;Jeong, Jae-Hyun;Lee, Myeong-Hoon;Baek, Tae-Sil
    • Journal of Ocean Engineering and Technology
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    • v.30 no.4
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    • pp.334-340
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    • 2016
  • The combustion chamber of a diesel engine is often exposed to a more serious wear and corrosion environment than other parts of the engine because its temperature increases as a result of using heavy oil of low quality. Therefore, repair and built-up welding methods must be performed on worn or corroded parts of the piston crown, exhaust valve, etc. from an economical point of view. In this study, Inconel 718 filler metal was used in repair welding on the groove of a forged steel specimen for a piston crown, along with built-up welding on the surface of another forged steel specimen. Then, the corrosion characteristics of the weld metal zone for the repair welding and the deposited metal zone for the built-up welding were investigated using electrochemical methods in a 35% H2SO4 solution. The deposited metal zone indicated better corrosion resistance than the weld metal zone, showing a nobler corrosion potential, higher impedance, and smaller corrosion current density. It is considered that metal elements with good corrosion resistance were generally included in the filler metal, and these elements were also greatly involved in the deposited meta by built-up welding, whereas the weld metal consisted of metal elements mixed with both the filler metal and base metal elements because of the molten pool produced by the repair welding. Finally, it is considered that the hardness of the weld metal was increased by the repair welding, whereas the built-up welding improved the corrosion resistance of the deposited metal.

Estimation of Fatigue Life in Butt-Welded Zone of SM45C Steel Rod (강 봉(SM45C) 맞대기 용접부의 피로수명 평가)

  • Oh, Byung-Duck;Lee, Yong-Bok
    • Journal of Welding and Joining
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    • v.26 no.3
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    • pp.45-50
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    • 2008
  • SM45C steel rods being used generally for power transmission shafts and machine components was selected and welded by Butt-GMAW(Gas Metal Arc Welding) method. An estimation of fatigue life was studied by constructing S-N curve. Fatigue strength of base metal zone showed higher values than one of weld zone in low cycles between $10^4$ and $10^6$cycles. However, significant decrease in fatigue strength of base metal was found around $10^6$cycles, which were almost same as one of heat affected zone. This decrease was attributed that initial residual stress of the steel rods distributed by drawing process was diminished by continually applied load, and resulted in softening of base metal. The fatigue limit of the weld zone was highest in the boundary between deposited metal zone and heat affected zone, and followed by in the order of deposited metal zone, base metal zone, and heat affected zone. Based on these results, it is revealed that the stress for safety design of machine components using SM45C butt-welded steel rods must be selected within the region of the lowest fatigue limit of heat affected zone.