access icon openaccess The effect of laser shock peening on hardness and microstructure in a welded marine steel

Residual stress is generally considered as the main criterion in laser shock peening for enhancement of fatigue life. However, changes in material hardness, microstructure and surface roughness can also affect component performance. These three aspects are investigated in this paper for welded marine steel samples subjected to laser peening. After laser peening an increase in hardness was seen across the weld and parent metal, with the local hardness dependent upon the initial hardness of the region before peening. The increase was relatively higher for the weld metal which had lower initial hardness. The local surface displacement profiles reflected the number of laser peening layers applied, and the peening also affected the distortion of the specimen after welding.

Inspec keywords: welds; laser materials processing; steel; surface roughness; surface treatment; internal stresses

Other keywords: surface roughness; material hardness; local surface displacement profiles; welded marine steel; weld; component performance; microstructure; fatigue life; residual stress; parent metal; laser shock peening

Subjects: Laser materials processing; Laser materials processing; Surface treatment and coating techniques; Engineering materials; Joining processes and welding

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