This paper discusses issues related to modifying the structure of material depending on the amount of silicon carbide additive and on the applied cooling rate. The study was conducted for Astaloy CrL modified powder with 1 wt.% or 3 wt.% SiC addition and 0.6% C introduced through mechanical alloying. It was concluded that the MA process as well as the addition of silicon have a significant influence on lowering the temperature of iron alloyed with 1.5 wt.% Cr and 0.2 wt.% Mo transformation. Moreover, changing the cooling rate has a very significant influence on formation and control of the sintered material's microstructure. It was further observed that silicon carbide decomposes and silicon diffuses into the Astaloy CrL base powder. (C) 2013 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.