Presentation Information

[20p-B205-10]Dry Laser Peening of 1180MPa Grade Ultra-High Strength Steel in Vacuum

〇Yoshiki Komatsubara1, Tomokazu Sano1 (1.Osaka Univ.)

Keywords:

femtosecond laser,laser peening,ultra-high strength steel

Dry laser peening (DLP) processing is a method that aims to enhance the fatigue properties of metallic materials using femtosecond laser-driven shock wave, which induces surface hardening and compressive residual stress through the shock-induced plastic deformation. The objective of this study is to investigate the DLP effects on ultra-high strength steel processed in vacuum in order to avoid the air breakdown. DLP treatment was performed on 1180 MPa grade ultra-high strength steel in vacuum using pulse energies ranging from 0.5 mJ to 5 mJ with a wavelength of 800 nm wavelength and a pulse width of 100 fs. The results confirmed the presence of significantly high compressive residual stress on the surface of the specimens under various laser irradiation conditions. This study demonstrates that DLP treatment in vacuum can achieve a significant peening effects on such a high strength steel.