ALUMINUM CARBONITRIDE AND ITS EFFECT ON THE PROPERTIES OF DYNAMO STEEL

Aluminum carbonitride Al5C3N was observed in low-carbon dynamo steel c ontaining 0.20-0.30% aluminum. The carbonitride precipitates are influ enced by the schedule of recrystallization annealing: slow heating of steel in a bell furnace promotes the formation of the carbonitride, wh ereas rapid heating during continuous annealing favors decomposition o f the carbonitride into two phases, Al4C3 and AlN. Aluminum carbonitri de crystals are coherent with grains having an octahedral orientation which is the reason of their stability in the structure of annealed st eel. in contrast, aluminum carbide crystals are coherent with grains o f cubic orientation. Dynamo steal recrystallized under conditions of c ontinuous annealing possesses better magnetic properties compared with steel annealed in bell furnaces.