KRAUS Martin VSB-Technical University of Ostrava

Spoluautoři BYSTRIANSKÝ Jaroslav, MAREŠ Vratislav

Incidence of long term operating conditions with complex influence of many factors results in a properties degradation of structural unit. These processes effect on all metals volume or surface only. And influencing for example mechanical properties or materials decrease in various range. This paper deals with materials degradation of tubular heat resistant steel components of the power plants pressure circuit components after operational exposition range from 80 000 till 190 000 hours. A lot of types of destructive and others testing methods and number of test for each of them were used to clarify of the extent and mechanism of the damage these components. Changes of material properties were by those methods evaluated in state after operational exposition and after heat reprocessing, always in the entire profile of the wall thickness of structural part. Measured values of properties were compared with the assumed properties of the non-degraded material in origin state. The specific problem is inhomogeneity (values oscillation) by wall thickness and perimeter of tubular parts. Generally is possible to find, material failing to satisfy several parameters of standardised required mechanical properties for new products from mentioned steel.

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