HIGH-TEMPERATURE PROPERTIES OF MCRAIY(TI, HF) COATED STEEL X 45 CRSI 9 3 AT 600-DEGREES-C AND 700-DEGREES-C

Within the COST-project 501.2 WP6 several plasmasprayed MCrAlY- and Zi rkonia-coatings were tested for application in diesel engines as anti corrosion coatings and as thermal barrier coatings respectively.With c oated and uncoated specimens of steel X 45 CrSi 9 3, creep tests up to 1700 h at 600 and 700-degrees-C were carried out in air and under str eaming hot gas simulating diesel engine exhaust gas. Under the hot gas condition a strong sulphur induced corrosion occurred at the nickel- and ironbase alloys. Silicon containing alloys exhibited the best hot gas corrosion resistance. An additional thermal barrier coating increa sed the corrosion resistance effectively. In all cases the coated spec imens exhibited a higher creep strength in comparison to the uncoated specimens. However, no strength decrease due to the hot gas corrosion was observed.