Abstract
Laser peening introduces compressive residual stresses on the surfaces of various materials and is effective in enhancing fatigue strength. Using a small microchip laser, with energies of 5, 10, and 15 mJ, the authors applied laser peening to the base material of an HT780 high-strength steel, and confirmed compressive residual stresses in the near-surface layer. Laser peening with a pulse energy of 15 mJ was then applied to fatigue samples of an HT780 butt-welded joint. It was confirmed that laser peening with the microchip laser prolonged the fatigue life of the welded joint samples to the same level as in previous studies with a conventional laser.
Highlights
Steel structures as used in industry and in social infrastructure, such as bridges, buildings, power plants, energy storage, and transportation, are important social capital stock in Japan
MLPare areequivalent equivalenttotothe theprevious previousstudies studiesresults resultswith withaaconvenconven tional large laser, and it can be said that there is a large improvement in fatigue strength
Tional large laser, and it can be said that there is a large improvement in fatigue strength In Figure 15, it is shown that these values are exceeded by adding arrow marks to those
Summary
Steel structures as used in industry and in social infrastructure, such as bridges, buildings, power plants, energy storage, and transportation, are important social capital stock in Japan. Much of this social capital stock was constructed during Japan’s rapid growth in the 20th century, and is approaching the end of its design life. Its renovation and maintenance have become an urgent matter. With the increases in traffic volume and weight in recent years, cracks have been found in highway bridges that far exceed the expected number and length. The importance of improving fatigue strength by replacement, repair or reinforcement of steel bridges is widely recognized. Of the various methods (shot peening [1,2,3,4,5], hammer peening [6,7], ultrasonic impact treatment [8,9], laser peening [5,10], cavitation peening [3,4,5], water jet peening [5], etc.)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
