TY - JOUR AU - Tatyana MECHKAROVA AU - Yaroslav ARGIROV AU - Daniela SPASOVA AU - Aneliya STOYANOVA PY - 2021/03/15 Y2 - 2024/03/29 TI - Structural Changes of Nitrogen Ferrite After Aging in Temperature Interval up to 100 °С JF - The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science JA - mms VL - 44 IS - 1 SE - Articles DO - https://doi.org/10.35219/mms.2021.1.04 UR - https://www.gup.ugal.ro/ugaljournals/index.php/mms/article/view/4319 AB - This paper aims to determine the extent of aging of nitrogen ferrite at temperatures below 100 °C and the structural and strength changes that occur in the process. The tests are carried out on samples of technically pure iron (Armco). The specimens are pre-deformed by tension and re-crystallisation heating to achieve a large-grain ferrite structure. A large-grained structure has been chosen to more accurately track the change in micro-hardness of the individual grains during the aging process. Nitric ferrite results from gas carbonitriding and subsequent hardening. Upon hardening, the samples are stored in a refrigerator, and then the surface layer formed is removed through electrochemical corrosion. Afterwards, aging heat treatment at temperatures below 100 °C is undertaken. After the aging process, micro-hardness of the individual grains is examined and X-ray structural analysis is performed. ER -