Burner rig and laboratory tests have been used as part of a systematic investigation of the corrosion performance of gas turbine materials under exposure conditions anticipated in solid fuel fired gas turbines. In the burner rig tests carried out, candidate coatings and base alloy materials (eg IN738LC) have been exposed at metal temperatures of similar to 650-900 degreesC to combusted gas streams of up to 1200 degreesC for periods of up to 4000 hours. The combustion gas streams have been doped with realistic levels of both gaseous (SOx and HCl) and vapour phase (Na, K, Pb, Zn) contaminants, Parallel laboratory tests have been carried out using the well established 'deposit replenishment' technique, with 'deposits' of Na, K, Pb and Zn compounds and realistic partial pressures of SO. and HCl. The performance of materials in all these tests was determined by use of accurate measurement techniques based on pre-exposure contact metrology and post-exposure optical microscopy/image analysis. The results of the laboratory tests have been used to upgrade existing corrosion models, with predictions correlating well with the burner rig results.