• 제목/요약/키워드: Erichsen test

검색결과 36건 처리시간 0.024초

알루미늄 레이저 용접에서 용접부 성형성 평가와 성형성 예측 모델 개발에 대한 연구 (Weld Formability Evaluation and Formability Estimation Model Development in Aluminum Laser Welding)

  • 박영환
    • 한국레이저가공학회지
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    • 제13권3호
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    • pp.7-12
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    • 2010
  • In this study, laser welding of aluminum AA5182 with AA5356 filler wire was carried out and the formability of the weld joint was evaluated through Erichsen test according to laser power, welding speed and wire feed rate. Fracture was occurred in both directions, perpendicular and parallel to the weld line at 0.75 of Erichsen ratio. Second order Regression model to estimate Erichsen ratio with experimental variables was proposed and the performance of model was evaluated with F-test and average error rate.

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피복된 판재의 성형 특성에 관한 실험적 연구 (An Experimental Study on the Forming Characteristics of Pre-Coated Metals)

  • 김호윤;왕신일;배원병
    • 소성∙가공
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    • 제9권5호
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    • pp.463-468
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    • 2000
  • An experimental study has been performed to investigate the forming characteristics of pre-coated metals(PCMs) widely used in domestic appliances through Erichsen tests and deep drawing tests. Erichsen tests are performed to find out the forming limits of seven pre-coated metals in normal conditions. Rectangular deep-drawing tests are carried out to know the effects of die materials and blank metals on forming loads and surface defects of final PCM products. In the deep-drawing test, four die materials [STD11(TiCN), STD11, STD11(TD), AMPCO] are used. In the Erichsen test, the forming limits of PCMs are obtained from flaking or crack of pre-coated films and lower than those of base metals. In respect of surface roughness and forming load, STD11(TD) and AMPCO materials are superior to my other die-materials used in the deep-drawing test.

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보론강 용접 맞춤 판재의 고온 에릭슨 커핑 평가 (Formability Evaluation of Tailor Welded Blanks of Boron Steel Sheets by Erichsen Cupping Test at Elevated Temperature)

  • 김영일;김지훈;김용;이문용;문영훈;김대용
    • 소성∙가공
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    • 제20권8호
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    • pp.568-574
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    • 2011
  • The combination of tailor welded blank (TWB) and hot stamping often offers improved crash-worthiness and reduced mass of stamped parts in the automobile body. To investigate the formability of laser TWB and the reliability of weld line, the present study used 22MnB5 boron steel sheet of the same thickness and used the Erichsen cupping test at elevated temperatures. The effects of laser direction, die temperature, weld line positions and forming speed on formability(the limiting dome height) were studied and the results were compared with the formability of the base material.

STUDY ON HIGH SPEED WELDING IN GTA WELDING PROCESS

  • Cui Li;Jeong, Ho-Shin;Park, Byung-Il;Kim, Sung-Kab
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.89-93
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    • 2002
  • A study of noticeable improvement in welding speed in thin-plate Type 304 stainless steels gas tungsten arc (GTA) welding was investigated. The welding speeds were increased to more than 3m/min, up to 8m/min. During the welding, Direct Current Straight Polarity (DCSP) and pulsed current GTA welding processes were carried out, respectively. The appropriate high speed welding parameters were established while achieving a high quality weld. After this, Erichsen test and tensile test were performed. The results obtained wert summarized as following: ultra high speed welding for thin-plate Type 304 could be satisfactorily welded with high speed from 3m/min to 8m/min in both DCSP and pulsed GTA welding; Increasing welding speed was found to decrease the ductility, tensile strength md elongation of welded joint; The optimal frequency would be 200Hz-500Hz for high speed welding in pulsed current welding; DCSP welding could obtain the better results of Erichsen test and tensile test than those of pulsed current welding obtained.

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매쉬심 용접판재의 성형 특성에 관한 실험적 연구 (An Experimental Study for Forming Characteristics of Mash Seam Welding Sheets)

  • 이명호;신외경;금영탁;황보원;유동열
    • 소성∙가공
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    • 제9권6호
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    • pp.582-589
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    • 2000
  • In recent automotive industry, vehicle weight can be reduced by one-step forming of tailored blanks welded with two or more sheets of metal blanks. Mash seam welding shows an overlap joint, a much wider welding area, and heat affected zone(HAZ) than a laser welding. This paper deals with the forming characteristics of mash seam welded tailored blanks. Mash seam welded blanks of same or different thickness combinations were prepared, and tensile, hardness, erichsen, and dome stretching tests were done.

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18Cr 페라이트계 스테인리스강의 용접부 저온 특성 평가 (Evaluation of Low Temperature Properties in 18Cr Ferritic Stainless Steel Welds)

  • 이원배;우인수;엄상호;이종봉
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2007년 추계학술발표대회 개요집
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    • pp.138-140
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    • 2007
  • This study aimed to evaluate the low temperature properties of the 18Cr ferritic stainless steel weld. Applied welding methods were LB(Laser Beam) and GTA(Gas Tungsten Arc) welding to compare the different low temperature properties of the welds. Low temperature properties were evaluated by the Charpy impact, Erichsen and Expansion test at low temperature. LB weld showed superior low temperature properties in the cases of the Charpy impact test and expansion test at low temperature, while GTA weld showed a superior low temperature property in the case of Erichsen test at low temperature. The different low temperature properties with test methods are still under analysis and may be due to different crack path depending on the microstructure, test speed and stress concentration during test.

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Effect of Welding Speed on the Microstructure and Mechanical Properties of Austenitic Stainless Steel Welds

  • Li, C.;Jeong, H.S.
    • International Journal of Korean Welding Society
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    • 제3권1호
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    • pp.23-28
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    • 2003
  • The effect of the welding speeds on the weld bead shape, microstructure, and mechanical properties in type 304 austenitic stainless steels was investigated by microscopic test, Erichsen test and tensile test. In this study welds were produced using autogeneous Direct Current Straight Polarity (DCSP) and pulsed current GTA welding. This study shows the ferrite content, ductility, tensile strength and elongation of high speed welds are decreased with increasing welding speed. The high speed welds exhibits satisfactory tensile strength, though the ductility is not good as that of the base metal.

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새로운 개념의 Tailored Blank 레이저 용접성 경가 방법에 관한 연구 (New Concept in Evaluation of Laser Tailored Blank weldability)

  • 정봉근;고광문;정경훈;이창희
    • 한국레이저가공학회지
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    • 제2권1호
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    • pp.61-67
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    • 1999
  • This study introduces the new concept in the evaluation criteria of the $CO_2$ laser Tailored Blank weldability, The materials used are 0.7mm, 1.5mm thick low carbon automotive galvanized steels. Welding tests were conducted for both similar thickness(0.7mm-0.7mm, 1.5mm-1.5mm) and dissimilar thickness(0.7mm-1.5mm) cases. The criteria developed for optimum welding conditions were based on relationship between results of die press forming test, weld transverse tensile test Erichsen test and weld penetration measurements. Application of the developed criteria(fracture ratio, strength ratio and D/To) in obtaining optimum welding condition revealed that a weld which satisfied any of the criteria did not fracture during actual die press test.

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유한요소법과 연성파괴이론에 의한 AZ31합금 판재의 온간 드로잉 공정에서의 파단예측 (Failure Prediction for an AZ31 Alloy Sheet during Warm Drawing using FEM Combined with Ductile Fracture Criteria)

  • 김상우;이영선
    • 소성∙가공
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    • 제21권4호
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    • pp.258-264
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    • 2012
  • The forming failure of AZ31 alloy sheet during deep drawing processes was predicted by the FEM and ductile fracture criteria. Uniaxial tensile tests of round-notched specimens and FE simulations were performed to calculate the critical damage values for three ductile fracture criteria. The critical damage values for each criterion were expressed as a function of strain rate at various temperatures. In order to determine the best criterion for failure prediction, Erichsen cupping test under isothermal conditions at $250^{\circ}C$ were conducted. Based on the plastic deformation histories obtained from the FE analysis of the Erichsen cupping tests and the critical damage value curves, the initiation time and location of fracture were predicted under bi-axial tension deformation. The results indicate that the Cockcroft-Latham criterion had good agreement with the experimental data. In addition, the FE analysis combined with the criterion was applied to another deep drawing process using an irregular shaped blank and these additional results were verified with experimental tests.

오스테나이트계 내열 스테인리스강의 용접성 평가에 관한 연구 (The Study on Evaluation of Weldability of Austenitic Heat Resistant Stainless Steel)

  • 변경일;지병하;정호신
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2000년도 추계학술대회 논문집
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    • pp.236-239
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    • 2000
  • It is important to evaluate austenitic heat resistant stainless steel because of low weldability of austenitic heat resistant stainless steel containing high Si. This study took varestraint test for evaluation of solidification cracking sensitivity and Erichsen test for evaluation of weld metal ductility. As a result of tests, solidification crack sensitivity increased with adding $N_2$ to shielding gas, and W had detrimental effect on crack resistance, but Ce had beneficial effect on crack resistance. Under same heat input, ductility of weld metal increased with welding speed.

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