Heat treatment of wrought iron

Appendix G
Heat treatment of wrought iron
G.1. General provisions
G.1.1. Heat treatment of wrought-iron gear should consist of
heating the gear uniformly in a suitably constructed muffle furnace
until the whole of the metal has attained a temperature between
600˚C (1,100˚F) and 650˚C (1,200˚F), then withdrawing the gear
from the furnace and allowing it to cool uniformly.
G.1.2. If the past history of wrought-iron gear is not known,
or if it is suspected that the gear has been heat-treated at an incor-
rect temperature, before putting it to work it should be given nor-
malizing treatment (950˚-1,000˚C or 1,750˚-1,830˚F) followed by
uniform cooling. Precautions should be taken during the heat
treatment to prevent excessive scaling.
G.1.3. Sling assemblies should be made of materials having
similar properties.
G.1.4. However, if the assembly has some components of
wrought iron and others of mild steel (e.g. mild-steel hooks per-
manently connected to wrought-iron chains), it should be nor-
malized at a temperature between 920˚ and 950˚C (1,700˚ and
1,750˚F), removed from the furnace and cooled uniformly.

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