Sintered metal parts and method for the manufacturing thereof

摘要

The invention relates to a method consisting of the steps of providing a pre-alloyed iron-based metal powder comprising at least 1.3-3.5% chromium, 0.15-0.7% molybdenum, manganese and unavoidable impurities, mixing said powder with 0.1-1.0% graphite, compacting the obtained mixture at a pressure of at least 600 MPa, sintering the compacted part in a single step at a temperature above 1100° C., shot-peening the part and after sintering optionally hardening the component. The invention also relates to a powder metallurgical part and use of a low chromium prealloyed powder for preparing notched sintered parts having a bending fatigue limit of at least 340 MPa at a sintered density of 7.15 g/cm³, preferably at least 400 MPa at a sintered density of 7.3 g/cm³.