Normalising

  • Normalising is a process typically used to homogenise or stabilise materials that have been rolled, cast, welded or proof machined.
  • The basic normalising process applied to carbon, carbon-manganese and some low alloy steels consists of heating to a high temperature typically in the range of 830°C to 930°C (austenitising temperature), soaking at that temperature then followed by air cooling (natural or forced depending on material and requirements).
  • Commonly carried out on carburising steels prior to most machining, where the processing temperature should be above the final carburising temperature.
  • Normalising carried out on carbon/low alloy steels that are to be subsequently hardened and tempered can be carried out at or a little above the hardening temperature.
  • Normalising adds stability to materials that are subsequently to be machined or materials that will subsequently be through hardened and tempered or induction hardened.
  • In many materials promotes a fine grained homogeneous structure with more predictable properties.
  • Helps to ensure future dimensional stability. 
  • The process allows conditioning of the steel to ensure that the component responds suitably to a subsequent hardening operation with less distortion.
  • Stabilises grain size.
  • Can optimise tensile/yield strength (forced air cooling). 
  • Improved machinability of properly normalised material.
  • Normalising is used to refine and homogenise an existing microstructure, especially relevant to steels which require further processing, eg carburising.  It can soften, harden or stress relieve a material, depending on its initial state and chemical composition.
  • One specialised application of normalising, and normalise and tempering is in the pre-treatment of alloy case hardening steel which ultimately will be subjected to high carburising temperatures.  To control distortion and generally increase stability, these materials benefit from a specialised high temperature normalise (and if necessary final temper) treatment before machining to the grinding stages.
  • This treatment is mainly applied to carbon, low alloy steels, certain SG and cast irons, and copper alloys, 080M40 (EN8), 070M55 (EN9), 150M19 (EN14), 150M36 (EN15), 070M20 (EN3), 655M13 (EN36).
  • Components up to 1120mm diameter and 1730mm long can be treated vertically using special jigging.  Weight up to 2000Kg.

James Menzies

Production

Leonard Powell

Technical Planner

David Wright

Production Director

Mark Barron

Business Development Manager