Abstract

Fatigue crack growth test was executed to determine fatigue behavior in the metallic plates of AHSSDP350/ 600 however, this new material is widely used this day in automobile manufacturing industry henceforth controlling fatigue character is a major challenge in the production unit. The influence of laser shock peening with multiple choice of pulse energies on AHSS-DP350/600 was investigated and its improvement of material properties was the ultimate objective. Measuring compared of both residual stress and fatigue cycle behavior, observation of morphologies, impact hardness of facture surfaces and roughness/damage fractal was performed. It resulted that the compressive residual stress can be injected into the outer layer of the specimen, with LSP pulse energy of S20J, S30J, D20J, and D30J. It again indicated that shocking pulse of square sharp edge introduced tiny cracks on the outward layer which the wave’s inner compressive residual stress vice versa with enclosure significantly stepped up with enlargement of LSP coverage area. LSP sample of D30J significantly revealed higher influence among other specimens.

Keywords: AHSS-DP350/600; Laser shock peening; Fatigue crack growth; Pulse energy; Residual stress; Fatigue crack initiation