Normalising

What is normalising?

Normalising removes inhomogeneities in the structure and produces a finer grain. It is mostly applied to semi-finished products or steel castings to improve machinability and the material’s response to later heat treatment.

How is it done?

The part is heated slightly above the transformation temperature of the steel (roughly 830–930 °C for unalloyed steels), held there until the structure has fully transformed to austenite, and then cooled in still air. Air cooling gives a finer, more regular structure than annealing with slow furnace cooling; since there is no quenching, the part does not harden.

Which parts?

Normalising is also useful for refining the coarse grain of parts exposed to uneven heat, such as parts forged or rolled at high temperature, or areas around weld seams. Typical examples are forgings, flanges, cast housings and welded structures made of carbon, quenched and tempered or engineering steels.

For a quote

State the steel grade, how the part was made (forged, cast, rolled or welded), its dimensions and weight, and any processes to follow normalising in the quote form.