CORROSION-RESISTANCE OF AUSTENITIC STEELS AND ALLOYS IN HIGH-TEMPERATURE WATER

An ampoule corrosion tests technique is presented for making a compara tive corrosion-proof estimation of austenitic steels and alloys which are candidate materials for the ITER first wall and shield blanket. In fluence of Cl- on the rate and character of corrosion cracking has bee n determined. The dependence of time before destruction on Cl- content s was obtained by experiments in twice-distilled water at a Cl- conten t value of less than 0.05 mg/l. Kinetics of a corrosion crack growth h as been determined by way of acoustic emission and measurement of elec trical resistance. It has been revealed, that corrosion cracking of 31 6L and 316Ti steels in water with 100 mg/l of Cl- takes place at tempe ratures over 50 degrees C. For 316L (Russian analogue), 316Ti, 08Cr18N i10Ti (type 304), 00Cr16Ni15Mo3Nb (type 316) steels and CrNiMo-1 (42-4 7%Cr, 1%Mo, Ni-base) alloy corrosion long-term strength and crack-resi stance characteristics were obtained. Results of tests show, that corr osion characteristics are near the same for all austenitic steels unde r investigation with CrNiMo-1 alloy being the exception. It was not de stroyed during ampoule tests.