PULVERMETALLURGISKT FOERFARANDE SAMT ANORDNING FOER ATT UTFOERA FOERFARANDET

摘要

The high alloy or superalloy steel or mixt. is packed in a capsule so that the pore volume is 20-35% of the total capsule volume i.e. a relative pore volume of 0.2-0.35. The capsule is closed and heated to above 900 deg.C. The capsule is then deformed so that the compression zone completely surrounds at least part of the body. This is carried out so that there is a continuous tapering of the part from an initial portion. The capsule is step-wise fed forward after each flow of the tool. The capsule thus undergoes compression given by equation (I) (where Ho(in) is the height of a unit of an arbitrary distance from the centre line in the cross-section of the initial portion and (Hi(out) corresp. for the other portion. A signifies the corresp. areas. X is at least 0.8. Vp is the relative pore volume in the capsule before compression.