Abstract: According to konopicky's theory, the interrelation between specific pressure (P) and relative density (Rp) of iron powders compacted in a pressure range of 20-80kgf/mm² can be defined by means of following equation:
P=Aln$\frac{{1-{\rm{Ro}}}}{{1-{\rm{Rp}}}}$
in present paper the compressibility of iron powders with the code name of AG, CD, T J, AS and YQ, etc. from different plants are studied by this theory.The composition,particle size apparent density and flowability of above iron powders have been determined and the changes of value A and Ro of iron powders before and after annealing have been calculated. The influence of above factors on the compressibility has been discussed. By measuring the equal density curves,the changes of compact density of iron powders with different particle size and different pressure were investigated.
The present has prove work that the sieve classification and blend of iron powders are useful to improve the qualities and extend the varieties of iron powders. The annealing process is necessary to improve the compressibility of iron powder and to get medium and high compact density.