Effect of laser clad repair on the fatigue behaviour of ultra-high strength AISI 4340 steel
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Date
2014-06-12
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
The fatigue behaviour of an ultra-high strength steel (>1800 MPa) was evaluated to assess the potential of using laser cladding as a repair tool for such steels in aeronautical structural applications. AISI 4340 and AerMet 100 steel powder were used to clad over a grind-out region in an AISI 4340 steel substrate using a 2.5 kW ND:YAG laser. Post-clad heat treatment (PCHT) was also investigated. Results showed very poor tensile properties and significantly reduced fatigue life of the AISI 4340 as-clad with a very high hardness and brittle fracture in the clad and HAZ zone. Residual stress results showed a compressive residual stress in the clad region and tensile residual stress in the HAZ. Changing the alloy of the clad layer to AerMet 100 steel, as well as applying a PCHT process, showed promising results as the fatigue life was improved from that of the grind-out substrate. © 2014, Elsevier B.V.
Description
Keywords
Fatigue, Stainless steels, Lasers, Residual stresses, Cladding, Tensile properties
Citation
Sun, S. D., Liu, Q., Brandt, M., Luzin, V., Cottam, R., Janardhana, M., & Clark, G. (2014). Effect of laser clad repair on the fatigue behaviour of ultra-high strength AISI 4340 steel. Materials Science and Engineering: A, 606, 46-57. doi: http://dx.doi.org/10.1016/j.msea.2014.03.077