Fatigue crack growth in some PM low alloy steels consolidated by rotary forging and sintering

Fatigue crack propagation rates under plane strain conditions have been inv estigated for three PM low alloy steels consolidated to high densities by r otary compaction followed by sintering and heat treatment. It is shown that the densities and properties are intermediate between those of pressed and sintered materials and of powder forged materials. Threshold stress intens ities compare satisfactorily with those for wrought counterparts, but resis tances to crack growth are inferior to those of wrought steels. Possible re asons for the properties of the rotary compacted materials are considered i n the light of their microstructures and the behaviour of other PM material s. PM/0882.