Microstructural Evolution in Long Duration Creep Specimens of a Mn-Cr Austenitic Steel

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

RUEDL Erich;  MATERA Roberto; 

1995-03-15

JRC5262

https://publications.jrc.ec.europa.eu/repository/handle/JRC5262,