Influence of Sintering Temperature on Properties of Low Alloyed High Strength PM Materials
PM² TEC 2001, in New Orleans, USA. Author: Ulf Engström. New applications for PM steels are continuously introduced on the market. This is primarily due to development taking place within the PM industry but also a result of new designs of engines etc. Many of these new applications utilise the unique possibilities of PM to achieve high strength in combination with close dimensional tolerances with a minimum of manufacturing operations The diffusion alloyed materials D.AE and D.HP-1 and the completely prealloyed material Astaloy CrM are all aimed for applications combining high strength with close dimensional tolerances. These materials reach tensile strength levels in the range of 850 MPa to 1000 MPa after conventional compaction at room temperature and sintering in belt furnaces at1120°C/ 2048°F. By applying high temperature sintering i.e sintering at temperatures >1200°C/ 2200°F, these strength levels can be increased. By combining high temperature sintering with warm compaction PM materials with even higher strength levels can be obtained. In this paper the influence of sintering temperature on static properties for both convention-ally and warm compacted D.AE, D.HP-1 and Astaloy CrM is described. The effect of using higher sintering temperatures than 1120°C/2048°F on the dimensional change for these materials is also presented.