한국주조공학회

The evolution of microstructures in two rapidly solidfied niobium microalloyed steels was studied. These alloys were rapidly solidified by two powder process techniques: nitrogen gas atomization and centrifugal atomization. It was found that in both powder processes, powder particles larger than 20μм in diameter were martensitic, and that the nitrogen gas atomized particles solidified cellularly while those that were centrifugally atomized tended to solidify dendritically. Particles smaller than 1μм were not completely characterized because of wide variation in composition.