Improvement of the wear resistance of 20CrMnTi steel gear by discrete laser surface melting

•The depth of melting zone and heat affected zone of the discrete laser surface melted units was measured.•The microstructure, phase composition and element distribution of the discrete laser surface melted units were observed.•The microhardness, residual stress and surface roughness of the discrete laser surface melted units prepared by different laser scanning speeds were characterized.•Based on the gear bench test results, the improvement of the wear resistance of 20CrMnTi steel gear by discrete laser surface melting was investigated. The experimental results show that the discrete laser surface melted gear with larger cross-sectional area and volume will has better wear resistance.