26-57 MODIFICAREA STRUCTURII UNOR OŢELURI ÎNALT ALIATE ÎN URMA APLICĂRII UNUI TRATAMENT TERMIC ŞI CRIOGENIC (I)


STRUCTURE MODIFICATION OF HIGH-ALLOYED STEEL BY APPLYING A HEAT AND CRYOGENIC TREATMENT (I)
Cryogenic treatment completes the classic heat treatment of steels with higher carbon content of 0.6 %, bringing substantially improving on properties, being very simple. Application of cryogenic treatment immediately after hardening has led to the increase in the percentage hardness of highalloyed steels HS 18-1-1, RUL1 and X200Cr12 with 26.56 %, 34.5 % and 9.7 %. At the same time, Hardness Vickers values were increased with 41, 49 and 61 units, representing a 4.8 %, 6.3 % and 6.7 %, increase, as a result of martensitic transformation.
Keywords: martensitic transformation, low temperature, optical microscopy, Vickers hardness

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