Stellite 4 Alloy
Stellite 4 is a cobalt-based alloy having greater wear resistance than Stellite 6 and is used for applications subject to only moderate mechanical shock. It is a machinable casting alloy having extremely good high-temperature strength due to the higher tungsten and carbon contents. It has very good galling resistance at room and elevated temperatures. It exhibits a very low coefficient of friction when rubbed against itself and hard steels.
Stellite 4 is often used for dies, hot pressing, and hot extrusion of copper base and aluminum alloys. It has also been used with success in pumps in corrosive and erosive conditions. Stellite 4 is also used for bushings and sleeves for Zn-Al hot dipping process.
Nominal Composition
Base: Co
Cr: 30
W: 14
C: 1
Others: Mn, Fe, Si, Ni
Hardness HRC: 45-49
Typical UTS: 757 MPa
UNS: R30404
AMS: Not listed