This study concentrates on the annealing effects of a laser-treated area by a successive laser pass in a plain carbon, a chromium, and a tungsten steel. Transmission electron microscopy (TEM), optical microscopy (OM), and wear and hardness measurements revealed substantial effects on the properties and microstructure of the plain carbon and tungsten steel which have a partly martensitic cellular structure after the first laser treatment. Close to the melt zone, martensite was again formed, whereas further away, nucleation of carbides was observed. The hardness increased in the former area and decreased in the latter. An analytical model sustained that the softening is due to carbon diffusion and martensite tempering. The softer zone in the tungsten steel exhibited a decrease of wear rate relative to the not-annealed zone in contrast to the plain carbon steel. Besides some diffusion, no annealing effects were found in the chromium steel which possessed an austenitic cellular structure after the first laser treatment.

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In general, neon implantation is not very effective in reducing wear rates. However, neon implantation into laser-melted steel turns out to reduce the wear rate substantially as a result of a conversion of residual tensile stresses into compressive ones. Nitrogen implantation, on the other hand, at a high dose of 3×1017 ions/cm2 at 90 °C exhibits a deleterious effect on the wear performance. A brittle layer of ε-Fe2(C,N)1−x nitrides is formed. At a lower dose of 1×1017/cm2 or implantation of nitrogen at 150 °C, the wear rate is also reduced.

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