Subject: Suggestions for Wrought Iron?

From: [email-masked] (Ralph Snel)
Date: Wed, 26 Jan 1994 17:17:27 GMT

I managed to get my hands on a fair amount of wrought iron,
to be used for making laminated and damascus blades (whenever
I get good enough...). I've tried forgewelding a bit of
wrought iron to what is called 1770 steel here in Sweden, it's
one of the more forgiving steels, about 0.7% carbon.
The weld took perfectly (using quartz sand), but when I
hardened the laminated blade in water the back of the (wedge
shaped) blade cracked irregularly in the center, along the
entire length of the blade (so much for water... oil next time).

Any suggestions/warnings that I should know of when using
wrought iron like this? I guess the cracking was the result
of different thermal expansion coefficients for WI and 1770.

Anything else WI is particularly well suited for?

Ralph
[email-masked]

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From: [email-masked]
Date: 26 Jan 94 15:53:29 -0500

> Anything else WI is particularly well suited for?
You've experienced the wonders of delamination - the bane of the 
pattern-welding blade maker.  If the weld isn't good enough, 
delamination may even occur in an oil-quench.  The recommendation
that I got from some professional knife makers was to try to
limit forging the billet on line with the weld planes, i.e.,
                                  -----------
==> avoid hitting this surface => -----------
                                  -----------
     while pounding primarily on this ^^^^ surface.  Since you
will have to hit occassionally on the weld plane to prevent the
billet from getting overly wide, just be sure that the billet
is at a good welding heat and be sure to forge it a bit in the
normal plane to insure that if there was separation, it will
go away.  Also be religious about cleaning the weld surfaces -
even a bit of fire scale can come back to haunt you.  I keep a
small angle-grinder near the vise, so that when I make the notch
in the billet and start the fold, I can buzz off all scale from
the weld surfaces and slightly crown the surfaces to boot.  When
the weld is made, the flux and scale will then tend to flow out.
I've had great luck using wrought-iron and O1 (with apprx 300-
600 layers at termination) using a propane forge and commerical
heat-treating oil (of course, the 50lb power hammer helps).

Good luck - Steve Bloom (IronFlower Forge)

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From: [email-masked] (Doug Blain)
Date: 28 Jan 1994 17:57:29 GMT

Ralph Snel ([email-masked]) wrote:
: I managed to get my hands on a fair amount of wrought iron,
: to be used for making laminated and damascus blades (whenever
: I get good enough...). I've tried forgewelding a bit of
: wrought iron to what is called 1770 steel here in Sweden, it's
: one of the more forgiving steels, about 0.7% carbon.
: The weld took perfectly (using quartz sand), but when I
: hardened the laminated blade in water the back of the (wedge
: shaped) blade cracked irregularly in the center, along the
: entire length of the blade (so much for water... oil next time).

: Any suggestions/warnings that I should know of when using
: wrought iron like this? I guess the cracking was the result
: of different thermal expansion coefficients for WI and 1770.

  You might want to try the technique used by the Japanese when hardening
a samurai sword. A paste is made of water, fine powered clay, ground
charcoal and small amounts of abrasive material left over from the rough
grinding of the blades (I assume that a small amount of fine sand will
work). The paste is put onto the blade in a thichness approaching 1/4
inch. However the edge of the blade is scapped down to the bare metal (a
band anywhere from 1/8-3/4 inch). For some of the specialized effects that
the Japanese blades are famous for, scalloped edges, thin ribbons of paste
running to the edge, etc, create the multitude of different patterns these
blades exhibit. Once the paste dries, the entire blade is heated to cherry
red (described as the color of the rising moon in August). Once it is at
the right temperature the blade is thrust quickly into the water (the
water is luke warm) and quenched. The paste acts as an insulator to lessen
the hardening of the back. This keeps it flexible so it won't snap in
battle. The edge is glass hard and in the mixed high carbon steel used in
the blades, you get crystals of marsenite that are visible to the eye. 

  The charcaol in the paste helps keep the carbon loss down. The small
ribbons of paste (usually 1/8" apart and sometimes at angles, cause the
hard edge to have softer areas that acts to compartmentalize the edge so
that if a hard object is hit, the chipping will be contained within the
softer areas. 

  Once the blade has been cleaned up, some of the sword smiths follow up
with a second heating to a much lower temperature to help relieve some of
the internal stresses this process causes. Typically the Japanese start
out with much higher carbon content in their steel, up to 7-8% and allow
the repeated folding to reduce the carbon content to 4-5%. An excellent
book on the process is called 'The Art of the Japanese Sword' by Knapp and
Yoshinda. 

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 Doug Blain                                     Email: [email-masked]   
 Manager, Computing Centre Services             Phone: (519) 824-4120 x6475
 Computing & Communications Services            Fax:   (519) 763-6143
 University of Guelph
 Guelph, Ont., Canada.  N1G 2W1        
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