Low alloy steel substrates (1Cr0.5Mo), were coated by HVOF (High Velocity Oxy-Fuel) and arc spraying. The coatings were the Fe-based Metcoloy 2 (0.36Cl2.4Cr0.6Ni0.4Mn0.4Si) and Metco 3007 (80Cr(3)C(2)-16Ni4Cr). The microstructures, porosities and oxide inclusions were metallographically characterised. The coated samples were exposed in an erosion corrosion rig in air for two weeks at 520 degreesC or 550 degreesC. The erodent was alumina particles, less than or equal to 0.3 mm, velocity about 3 m/s and inclination angle 30 degrees. Solid 304 steel was used as a reference material. The erosion attack was determined by utilising a stylus profilometer. ABS and X-ray diffraction were used to characterise the oxides formed during exposure. The rates of the erosion corrosion attack of the coatings are about 0.7 +/-0.2mm/10000hr. The thicknesses of the oxides formed on the eroded area are considerably (about one order of magnitude) thicker than the oxides formed on a non-eroded area of the same sample. The mechanism of erosion corrosion is discussed.