Alloy　316　stainless　steel　(SS)　is　an　important　candidate　material　for　supercritical　water　oxidation　facilities,　but　severe　corrosion　negatively　affects　its　life-span　and　potential　application.　In　this　work,　ZrO2　and　TiO2　were　coated　on　the　316　SS　substrate　by　air　plasma　spraying　and　then　exposed　in　oxygenated　sub-　and　supercritical　water.　The　results　show　that　the　coatings　could　greatly　improve　the　corrosion　resistance　of　316　SS　in　oxygenated　sub-　and　supercritical　water　in　the　range　from　300　degrees　C　to　480　degrees　C　at　24　MPa　with　3　wt%　of　oxygen　content　for　100　h.　Increasing　temperature　accelerated　the　corrosion　of　tested　TiO2-　and　ZrO2-coated　samples.　ZrO2　and　TiO2　coatings　could　inhibit　the　outward　diffusion　of　metal　elements　in　the　316　SS　substrate　and　the　inward　diffusion　of　oxygen.　The　oxide　film　of　the　ZrO2-coated　sample　was　composed　of　Cr2O3,　Fe3O4,　Fe2O3,　NiFe2O4　and　NiCr2O4,　while　that　of　the　TiO2-coated　sample　consisted　of　Cr2O3,　Fe3O4　and　Cr2MoO6　at　480　degrees　C.　Compared　with　the　ZrO2　coating,　the　TiO2　coating　exhibited　better　protective　effects　on　reducing　316　SS　corrosion　in　oxygenated　supercritical　water.　The　TiO2-coated　sample　led　to　lower　absolute　values　of　weight　changes,　more　uniform　and　denser　corrosion　surface,　and　better　inhibition　on　the　outward　diffusion　of　metal　elements　(especially　Ni)　and　on　the　inward　diffusion　of　O.　This　suggests　that　the　TiO2　coating　on　the　316　SS　substrate　via　air　plasma　spraying　is　an　effective　approach　to　improve　316　SS　corrosion　resistance　in　tested　oxygenated　supercritical　water.　(C)　2019　Elsevier　B.V.　All　rights　reserved.