Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Role of Post Weld Treatment Methods in the Improvement of Fatigue Life for T-type Welded Structures Made by SM 50A Steel

SM 50A 강으로 제작된 T-형 용접형상의 용접후처리 방법이 피로수명 증가에 작용하는 역할

  • Han, Chang-Wan (School of Mechanical Engineering. Pusan National Univ.) ;
  • Lee, Jae-Hoon (School of Mechanical Engineering. Pusan National Univ.) ;
  • Song, Jun-Hyouk (School of Mechanical Engineering. Pusan National Univ.) ;
  • Lee, Hyun-Woo (School of Mechanical Engineering. Pusan National Univ.) ;
  • Park, Seong-Hun (School of Mechanical Engineering. Pusan National Univ.)
  • Received : 2011.08.03
  • Accepted : 2011.11.07
  • Published : 2012.03.01
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Abstract

This study aims to investigate the effect of the post weld treatments on the fatigue life of T-type welded structure made by a SM50A steel material, generally used for excavators, because changes in the geometry, material and surface properties of welded regions affect the fatigue life of welded structures. T-type test specimens were prepared by the CO2 welding of rolled steel plates (SM50A steel) with a thickness of 10 mm at a welding speed of 30 cm/min and these Ttype welded specimens were further treated by UIT (Ultrasonic Impact Treatment) and/or toegrinding post welding treatment methods. In order to investigate improvements on the fatigue life of the samples. 3-point bending fatigue tests were conducted with a stress ratio of R=0.1 under a cyclic loading environment at a frequency of 5 Hz, via a hydraulic fatigue testing machine (${\pm}100\;kN$, MTS 809). The tests were performed at room temperature. The fatigue life of UIT specimens was approximately 25 times longer than that of as-welded specimens at a stress amplitude of 281 MPa, while toe-grinding specimens exhibited 4.15 times longer fatigue life. The current results could provide important guidelines to determine the proper post weld treatment methodologies of T-type welded parts for excavators with a satisfactory fatigue life although under severe operating conditions.

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References

  1. Maddox, S. J., "Fatigue Strength of Welded Structures, 2nd Edition," Abington Publishing, pp. 17-37, 1991.
  2. Stephens, R. I., Fatemi, A., Stephens, R. R. and Fuchs, H. O., "Metal Fatigue in Engineering, 2nd Edition," John Wiley & Sons, Inc., pp. 401-427, 2001.
  3. Haagensen, P. J. and Maddox, S. J., "Specifications For Weld Toe Improvement by Burr Grinding, TIG dressing and Hammer Peening for Transverse Welds," International Institute of Welding Document, Commission XIII, Working Group 2, 2001.
  4. Almar, A., "Fatigue Handbook," TAPIR, pp. 259-285, 1985.
  5. Lee, H., Kim, J. and Kim, H., "The Static Overload Effect Estimations on Fatigue Strength by The Measurement of Local Strain Variation at The Weldment Toe," Journal of the Korean Society of Precision Engineering, Vol. 18, No. 6, pp. 59-66, 2001.
  6. Bergan, P., Lotsberg, I., Fricke, W., Francois, M. und Pisarski, H., "Overview of the FPSO : Fatigue Capacity JIP," Proceeding of the 18th International Conference on OMAE, Vol. 3, pp. 411-418, 2002.
  7. Statnikov, E. S., Muktepavel, V. O. and Blomqvist, A., "Comparison of Ultrasonic Impact Treatment (UIT) and Other Fatigue Life Improvement Methods," Welding in the World, Vol. 46, No. 3-4, pp. 20-32, 2002. https://doi.org/10.1007/BF03266368
  8. Galtier, A. and Statnikov, E. S., "The Influence of Ultrasonic Impact Treatment on Fatigue Behaviour of Welded Joints in High-Strength Steel," Welding in the World, Vol. 48, No. 5-6 , pp. 61-66, 2004. https://doi.org/10.1007/BF03266433
  9. Lihavainen, V. M., "A Novel Approach for Assessing the Fatigue Strength of Ultrasonic Impact Treated Welded Structures," Ph.D Thesis, Department of Mechanical Engineering, Lappeenranta University of Technology, 2006.
  10. Song, J. H. and Lee, H., "The effect of Ultrasonic Impact Treatment(UIT) for fatigue life of weldment," Trans. of Korean Society of Automotive Engineers, Vol. 18, No. 6, pp. 38-45, 2010
  11. Connor, L. P., "Welding Handbook, 8th Ed.," American Welding Society, Vol. 1, pp. 152-153, 1987.

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