Precipitation-hardening fine-grained structural steels, but not stainless steels
Precipitation hardening, or simply ‘hardening’, is a heat treatment comprising solution treatment and ageing. The hardening process is essentially based on the temperature-dependent solubility of the iron lattice for foreign atoms; in the case of unalloyed steels, these are mainly nitrogen atoms. These are responsible for the
generally undesirable ageing of the steel, which occurs over time, particularly in uncalm and semi-calm steels. Aluminium (Al), which is usually used for calming anyway, binds nitrogen (N) to form aluminium nitride (AlN.)
Typical materials in group 3.3
| Name / Grade | Number | Standard | Product | Remarks |
|---|---|---|---|---|
| K12521 |