Abstract: The problem of previour powder-particle boundary (PPB) was studied in a nickel-base P/M superalloy FGH95. The results indicate that carbides begin to form on the powder surface while atomization and continue to precipitate and grow into continous networks during HIP-consolidation. As a result of complex composition of carbides the different type carbides interact probably. The amount of PPB precipitation increases significantly during post-HIP heat treatment. The formation of PPB carbides is related to the amount of residual oxygen or oxygen contamination in alloy.