Jim , if my memory serves me correctly , the Straw color that you are
referring to is called Tempering , if you would bring a piece of High Carbon
Steel like a chisel or other tool up to red color and quench it in oil , it
would be very hard and have very little ductility , the reheating or
tempering to what I remember was about 450 deg. would make the part more
serviceable and less likely to shatter , the cherry red that we use to
finish out our TIG welds has somewhat the same effect except that it helps
to bring the entire cluster back to the original 90 ksi and removes the
push-pull and strain that is locked in for 1000 yrs. or so.
Phil
"Morgans" wrote in message
...

"Charles Vincent" wrote

4130 is indeed hardenable by heat treatment or cold working. And 4135
even more so. I have hardened them both using both water and oil
quenches, though if you took the time to read one of the metallurgical
tomes on the subject, you would find they are spec'd as an oil hardening
alloy. Water has worked fine for me on small sections, though my
default quench (i.e. the bucket next to the forge) is water with a layer
of olive oil floating on the top. I used to use used ATF or motor oil as
it was cheap, but burning olive oil is more friendly.

After you harden it by quenching, do you then go though the normalizing,
by heating to "straw" color, and over a period of several minutes, remove
the heat, a distance at a time?

That was what I was taught eons ago, but only in reference to working mild
"God only knows" what type of steel. I'm talking in cars and trailers and
tractors and such.

I hear people talking about heating up the weld and tube to "cherry" and
that is not what I thought was the proper procedure, for normalizing. I
was taught that "straw" was attainable, by barely seeing any color in a
semi-dark area.

Can anyone straighten out my conceptions, and mis-conceptions, here? g
--
Jim in NC