I recently aquired a 2 1/2" diameter by 5 1/2" long rod of D2 steel, and I'm taking a metalsmithing course this semester (will be retaking it in the fall, too). I plan to make many knives with it (and potentially daggers, if I get that far without it falling apart)
I've been doing some research, and it sounds like D2 is a nightmare to forge. Too hot, and it crumbles, too cold, and it cracks. Is it really that difficult to forge? Do you have any better explanation than temperatures (I don't have a thermometer that reads that high, so the temperature in degrees is utterly useless for me right now)? Things like "bright yellow, yellow-orange, orange, red-orange" will work for me, since it is a night class (hard to tell the temperatures during the day, in the Tucson sun!).
I will have access to a powerhammer, so that will allow me to get more drawing done than if I were doing it entirely by hand. Any estimates on how many seconds I can forge it with the powerhammer before I need to throw it back in?
If you're wondering why I chose D2, its because I've been reading up on it some, and it seems to be the best steel for holding an edge on a non-impact blade (impact meaning: swords, axes, etc, versus knives not really hitting/being hit by stuff). That, of course, was after I bought the steel (it was on sale)
Last edited by bstrickler; 04-28-2010 at 04:10 AM.
well you are asking for a very long explaination about metallurgical reactions and variables...
1st2 is an excellent alloy steel
its referred to by many makers as high chrome tool steel
its basically a tool steel with lots of chrome ,but not enough to make it stainless steel
as an alloy steel the many exotic elements it contains makes the temperature margin for forging less
with a power hammer you have the advantage of moving the steel quickly...
thats great if you're in the right temp. range
the only way to see is by doing it ...
generally speaking a cherry red is safe.
orange will be close to "red shorting"...thats too much time spent too hot,
that makes the grain growth too big and splits occur in the billet,especially if you try to move the steel too much under the hammer
its always good to feel the billet under a hand hammer to get a feel of it .
now when you hammer a red hot billet on the anvil you will see it slowly lose colour...
pay attention to the subtle colour shift...imagine a red oval shape on the billet,as it cools you will see a ring or shadow where the steel goes from red to darker red and back to the same red again...
this is important
whats happened is the crystalline structure of the steel has transformed,its under gone an energy exchange from martensite to austenite...basically you don't hit it after its had the darker shadow go through it..
if you're going to smack out that billet get it cherry red and try to make it 1" by 1/2"
for shaping later...it will hold the heat for a while if its big and fat...e.g less surface area.
also room temp anvil temp etc...all make a diff
at the 1" by 1/2 you get 10 to 15 seconds before it goes cold
don't hit it after the dull red is fading,it will start to sound more ringy as well
it should sound dull and even a bit wet.
if you don't get any sucess try using good old tool steel
O1 and 1000 series steel is the bread and butter stuff of bladesmiths
1075 is a great steel to work with ..very forgiving and lots of carbon for great sharp knives of just about any type...
small to big axes etc.
If I was you I would do a knifemakers course...there are many top makers all over the US...make friends and pick their brains...(that's in a non-zombie type of way)
I have made a few knives with D2, A machette a camp ax and a hunting/skinning knive. Super strong but a bitch to work with. A2 is also a nice steel I made a sushi knife from it. 1095 is a great non alloy steel easy to work with and a nice edge. Probably more than you wanted to know but...
my sushi knife