Enhancing Hardenability of Steels Through Advanced Quenching

Enhancing Hardenability of Low Alloy Steels Through Advanced Quenching A Comparative Study of Pressurized Water and Ultrasonic-Assisted Quenching Al Zughal Chaudhary IMAT 2026 — Poster Presentation Conventional quenching methods often fail to achieve sufficient hardened depth in low alloy steels, particularly in larger cross-sections, due to vapor blanket formation that insulates the part surface during cooling. This study investigates pressurized water and ultrasonic-assisted water quenching as alternatives, examining their effects on hardness profiles, residual stress distribution, and microstructural evolution across multiple low alloy steel grades (1018, A36, 1045), benchmarked against conventional water quenching. Hardness was characterized using Vickers and Rockwell C testing, residual stress via the hole drilling method, and microstructure through optical and SEM imaging with martensite fraction analysis. Ultrasonic agitation was found to disrupt the vapour blanket, increasing heat flux and promoting more uniform martensitic transformation, while pressurized flow sustained nucleate boiling and high heat transfer coefficients even in larger cross-sections where conventional quenching loses effectiveness. Both advanced quenching methods outperformed conventional water quenching, achieving at least a 5% increase in hardness, deeper hardened zones, and more favorable compressive residual stress profiles with reduced tensile stress at depth. These improvements were achieved without any change in alloy composition, offering practical, cost-effective value for industrial heat treatment. Future work will extend the study to additional steel grades and cross-section sizes, incorporate fatigue testing, CFD modeling of quench media flow, techno-economic analysis for scale-up, and optimization of ultrasonic and pressurization parameters. Acknowledgements: Dr Gopal Nadkarni, The University of Akron