what IS powder steel?
was asked once why a katana was so solid compared to, say, a leaf
spring of the same width. The answer is NOT the material. Not the
prayers. Not what your game designer says it is. The reason for the
solididity, the "stiffness" is the tension/compression created by the
uneven shrinking during the differential tempering. Imagine lifting up
a shelf of books by squeezing the stack of books together. You have a
beam. If you really really squeezed that pile of books, you would have a
beam strong enough to sit on. That's the physics behind it. If you
were to go to the same trouble to heat treat a tool steel sword the same
way the national treasures of Japan treat their folded swords, you
would get similar results. I can't even imagine how many ways there are
to screw it up though. My hat is off to the people who do this for a
Karl says it better....
(Karl is a regular member of the "sword forum", and is worth
following ON the sword forum. Below is the nicest explanation I
have ever seen of Powder Steel. And why it is a "little" better than
folded steel for some purposes.)
Karl ---> I believe I read something once that said there is a difference between
powdered steel, and particle steel (CPM steels). This link:
is a post by a fellow who describes the CMP process very well. He says
the CPM process is a powdered metal process. If I recall, there is a
difference between powder and particle methods, but it isn't significant
for a person wanting a general idea of what is going on.
Advantages of the powdered methods is that you get perfectly homogeneous
steel. Think of steel as a chocolate chip cookie. The dough is the
regu;ar steel parts, and the chips are the carbodes. Carbides are very
hard aloyed bits that can really make a nice toothy edge in a knife.
Mr. Larman said that Howard Clark's 1086 blades take longer to burnish
than "regula" blades, and they wear his burnishing tools faster. This
is because of the vanadium carbides in the steel. There are all kinds
of carbides. In stainless steel you'll get chromium carbides. Some
carbon steels have chromium in them too (not at levels to make them
stainless), forming chromium carbides. As you cut with yopur blade, you
are going to wear away the steel. As you sharpen, you wear away the
steel. Imagine if your chogolate chip cookie had clusters of chips with
lots of dough spaces in it. you can pictire the dough crumbling away
and leaving these odd clumps of chips, that now have little dough
support and such. In regular steel, you can get clumping of carbides
nad such because of migration of the carbides as the steel cools. With
particle metallurgy, you start with a bunch of tiny particles of the
perfect elemental make-up, and then you press them all together into a
solid billet. No migration, nothing. Just a perfect chocolate chip
Oh, I think that another advantage of this method is that you can make
alloyes that you can't make by traditional methods. Crucible (the
company, the makers od the CPM steels among others) has steels with
crazy amounts of vanadium, and amounts of carbon exceeding 2%!!!
The above was shamelessly ripped off from Karl's post on the Sword Forum.
Karl is a regular member of the "sword forum", and is worth following ON the sword forum. The above is the nicest explanation I have ever seen of Powder Steel. And why it is a "little" better than folded steel for some purposes.