On 04 Dec 2003 20:09:54 GMT, S (Whunicut) wrote:

Actually they are out of 'normaized' condition 4130 plate/sheet.
In the mean time annealed condition is still avaliable. Would an experienced
member please outline procedure for normalizing from annealed back to usable
normalized condition (prior?) to cutting out parts.

Thanks in advance, Lyle


In annealing an alloyed steel, the part is heated to just above the "critical"
(varies according to the alloy, 1550 degrees F rings a bell for 4130)
temerature. Around 50 degrees F above, IIRC, at which point the steel is single
phase austenite. The part is then slowly cooled, austenite is retained, as much
as possible. Steel is then very ductile and easy to work.
To normalize, the steel is first heat treated to the hardened state by, again,
heating to critical temperature but this time quenching in the proper medium
for that particular alloy. 4130, I think, can be either oil quenched or air
quenched. The steel is then tempered or "drawn" to the correct R "c" scale for
normalizing.
Some steels do not require the tempering step in the normalizing process and
can be cooled in still air from the critical temperature and be ready to go.
So...make your parts from the annealed material. It will work easier, bend
using a much smaller radius without cracking and be easier on your drill bits.
Take the parts to a commercial heat-treater and tell them you want the parts
normalized. Specify "no scale" and they will come back shiny and bright from
being heat-treated in a vacuum furnace or take them to a Tool&Die shop who will
probably heat treat them for free if you dont mind waiting until they have a
load to go into their furnace. To prevent scale, they will wrap the parts in SS
foil before placing in oven.

Regards,
Warren

I must admit to not understanding his question. In Australia
normalised and annealed mean the same thing.
Stealth Pilot