STRENGTH PROPERTIES CHANGE OF HYDROGEN CYLINDERS AT POWER GENERATING UNITS OF POWER PLANT FOR CONTINUOUS OPERATION

Abstract

The changes in exploitation characteristics after prolonged usage, and the hydrogen content in the samples with 45 steel used for the hydrogen manufacture cylinders are defined. By testing degraded material samples in the air sharp yield point which disappears during tests in hydrogen was observed. Main feature inherent in investigated material – metastability, that is the presence of more or less marked time-and temperature-dependent processes of structural relaxation. Degradation processes lead to exploitation properties changes. Intermediate (between baseline and after prolonged use) values of fracture toughness were chosen so as to minimize standard deviation (err) of experimentally obtained drift values from the theoretical curve corresponding exponential relaxation function.