Clad layers of chromium onto a mild steel substrate are obtained by low-pressure laser spraying and their composition dependence on impinged energy density is studied in detail with their microstructure and microhardness. When impinged energy density E(i) is selected to be 64 W mm(-2), the obtained clad layer consists of a Cr30Fe70 alloy. The thickness of the alloying layer decreases with decreasing impinged energy density E(i). A single phase of chromium grows when E(i) is selected to be smaller than 13 W mm(-2). The presence of CrFe alloying layer extremely enhances corrosion resistance on steel surface.