Enhancing Fatigue Strength in High-Strength Steel Welds: HFMI and TIG Dressing Techniques
The demand for lightweight structural solutions is driving the use of high-strength steels (HSS) in applications such as railway vehicles, bridges, offshore structures, and high-speed ships. Welding, the primary joining method for these structures, often faces challenges like stress concentration, tensile residual stresses, and locally deteriorated microstructures, making fatigue the key design consideration.
This study highlights advancements in post-weld treatment techniques to enhance fatigue strength and enable lightweight designs. Two widely used methods—High-Frequency Mechanical Impact (HFMI) treatment and Tungsten Inert Gas (TIG) dressing—are evaluated through a meta-analysis of over 1,500 fatigue data points. Key findings include:
Effectiveness of HFMI and TIG Dressing: Both techniques show promising improvements in fatigue performance, particularly under constant amplitude loading. HFMI, in particular, induces beneficial compressive residual stresses, while TIG dressing improves surface profiles but increases mid-plate stress.
Fatigue Regimes: HFMI-treated joints outperform others in medium- and high-cycle fatigue regions due to flatter S-N curves, while all methods converge in low-cycle fatigue due to localized plasticity.
Design Implications: Although TIG and HFMI treatments provide less improvement under spectrum loading compared to constant amplitude loading, they still enable significantly higher allowable stresses, contributing to lightweight design.
If you use our data please cite as:
@article{yildirim2017recent,
title={Recent results on fatigue strength improvement of high-strength steel welded joints},
author={Y{\i}ld{\i}r{\i}m, Halid Can},
journal={International journal of fatigue},
volume={101},
pages={408--420},
year={2017},
publisher={Elsevier}
}
Data availability:
Comments