The Effect of HFMI Treatment on Stress Concentration for S355J2C+N Steel with Fillet Weld Joint

Abstract

In this study, the effect of weld toe improvement application (HFMI) on stress concentration (Kt) was investigated. Welding connection and load type specified in IIW No. 511 / FAT 80 are preferred. The structure was joined with MAG welding and S355J2C+N was used as the main material. After the HFMI application, the geometry (width: 3 mm, 3.75 mm, 4.5 mm, 5.25 mm, 6 mm and depth: 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm) formed at the transition from the welding tip to the base material was determined as a variable and modeled using the Creo Parametric package program. These values are referenced from the IIW recommendations document. The structure was analyzed with the finite element method using the MSC Marc package program. This scope of work; only surface improvement was focused, compressive stresses after HFMI were not modeled. Analyzes were made by changing the transition geometry, and the stress values were read for each. According to the analysis results obtained, it has been observed that the stress concentration in the transition geometry decreases with the increase in width but increases with the increase in depth. In parallel with this result, the lowest stress concentration was seen in the geometry with 6 mm width and 0.2 mm depth dimensions.

Keywords

• High frequency mechanical impact (HFMI)
• Stress concentration
• Weld toe

References

1. Alden, R., Barsoum, Z., Vouristo, T., Al- Emrani, M. (2020). Robustness of the HFMI techniques and the effect of weld quality on the fatigue life improvement of welded joints. Welding in the World, 64, 1947–1956.
2. Askaynak. (2022, Jun 14). AS MIG SG2 performance. Retrieved from https://www.askaynak.com.tr/urunler/ kaynak-elektrodlari-telleri-ve-tozlari/gazalti-(mig-mag) -kaynak-telleri/as-mig-sg2-performance.pdf
3. Aydogdu, K., & Genel, K. (2002). Kaynaklı baglantıların yorulma dayanımını etkileyen faktorler. Sakarya University Journal of Science, 6(1), 84-89.