STUDY OF THE EFFECT OF DOUBLE ANNEALING ON THE QUALITY OF SPHEROIDAL GRAPHITE CAST IRONS
DOI:
https://doi.org/10.34185/1991-7848.itmm.2025.01.012Keywords:
cast iron, rolling roll, double annealing, structure, propertyAbstract
The study of the influence of double annealing on the structure and properties of rolled cast irons of the LShNM-58 design was carried out. As a result of the studies conducted using a complex plan obtained by combining plan 24 with a 4×4 Latin square, the optimal double annealing mode was selected: stage I - temperature 1000 °C, holding time 1 h; stage II - temperature 600 °C, holding time 3 h. Double annealing of cast irons of the working layer led to spheroidization of pearlite and graphitization of pearlite and eutectic cementite, in cast irons from the necks of the rolls - to a structure heterogeneous in morphology of eutectoid transformation products, which included graphite, ferrite, pearlite of different dispersion, bainite, martensite and phosphide eutectic. At the same time, the strength properties of heat-treated cast irons were higher than those of cast iron rolls by 8...96%. As a result of the research, a technology for high-temperature heat treatment of rolling rolls of the LShNM-58 design was developed, tested and recommended for implementation.
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