Hamon on D2 ???

[Dan Gray]

Uddeholm (BUCorp) spec for D2 at 1850° is a 40 minute soak, 1880° at 30 minutes. BUCorp starts at 1810° for 60 minutes and goes to 1920° for 30 minutes.

Crucible shows 1825° to 1875° and 30-45 minutes.

Timken Latrobe shows 1800° to 1900° all at 30 minutes soak.

for a thick piece say in tool and die making you'd have to soak longer depending on the thickness.
but for knives, 15min once at full temp should be a good avg..

galadduin
the steel will be a lot harder off the shelf than something like 1095 ( both annealed ,,) so it could have felt harder than it was.

 

[Steve Hayden]

Here is a link to Bohler/Uddeholm's publication, "Heat Treatment of Tool Steels"

http://www.bucorp.com/pdfs/UddeholmHeatTreatmentofToolSteel.pdf

An excerpt on soak time:

Holding time at hardening temperature
It is not possible to state exact recommendations
briefly to cover all heating situations.
Factors such as furnace type, furnace rating,
temperature level, the weight of the charge in relation
to the size of the furnace etc., must be taken
into consideration in each case.
We can, however, give one recommendation
that is valid in virtually all situations:
when the steel has reached hardening temperature
through its entire thickness, hold at this temperature
for 30 minutes. An exception to this rule is for
thin parts heated in salt baths at high temperature,
or high-speed steel. Here the entire period of
immersion is often only a few minutes.

 

[Dan Gray]

virtually in all situations: virtually means there are exceptions to the rule, remember we are a minority in the steel biz..

Here is a link to Bohler/Uddeholm's publication, "Heat Treatment of Tool Steels"

http://www.bucorp.com/pdfs/UddeholmHeatTreatmentofToolSteel.pdf

An exception to this rule is for
thin parts heated in salt baths at high temperature,
or high-speed steel. Here the entire period of
immersion is often only a few minutes.
virtually in all situations:

exactly
it's the edge we are looking to heat treat (it's very thin) salt baths conduct fast
so that's the answer there in equalizing the whole part.

I'm thinking also Bohler/Uddeholm isn't caring much about grain growth or Knife making or even polishing the steel
as we do.
D2 is a tool steel for dies. we are sorta out side the box here

edited to add
BTW
the times I qutoted are from the chart that TKS uses for all their customers knife blades that they treat..I'd dare say Paul Boss would be in this range also
I could be wrong though