Comparative investigation of corrosion of sheet and bar rolled steel 12Kh18N10T, 08Kh18N10T and 03Kh23N6 in boiling nitric acid

Comparative study of corrosion of the 03Kh23N6, 12Kh18N10T, 08Kh18N10T austenitic steels has been carried out. Sheets of two thickness (6 and 10 mm) and disks of two sizes (50 and 100 mm in diameter) of three steel types were tested in boiling solutions of pure nitric acid of the concentration 12 mol/l, and with additions of HF (20 mg/l) or HF(1g/l)+Al3+(2.7g/l). It is shown, that the 0323N6 austenitic-ferritic steel is considerably more stable in boiling concentrated solutions of nitric acid in the absence of somewhat significant difference between the sheet and disk even in the most aggressive solution, containing 1g/l HF and 2.7 g/l Al3+, where the difference does not exceed 20%. The disk of the 03Kh23N6 steel surpasses the disk of austenitic steels, as to the corrosion resistance in pure acid, by an order; in acid, containing fluorides, 16-20 times as much