[TheForge] A36 vs 1018

Wed Feb 11 19:36:57 EST 2009

Sounds like dong anything relaibly with A-36 that invlolves its 
matallurgical composition is hopeless.  As I appreciate it. "A-36" is a 
performance spec with a very loose chemical criteria.  that's why it costs 
32 buck to get the actual spec.. The chemical composition is highly 
variable, and can include manganese, phosphorous, sulphur, silicon and 
copper.  The Typical formulation is usually given with 25 points of carbon. 
But that's effectively an average, so its like saying if you have one foot 
in the fire and one in a block of ice, on average you're very comfortable.

If you need to forge weld often and consistently, I would pay the extra 
bucks for the 1018, or even try to find 1008 or 1010.  Look at it this way: 
even if the material costs twice as much, you wont be wasting it.

----- Original Message ----- 
From: "Paul N" <crosspein at sbcglobal.net>
To: "Blacksmithing List Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Wednesday, February 11, 2009 7:11 PM
Subject: Re: [TheForge] A36 vs 1018

> Thanks for the voice of experience. I guess when I see a spec like the
> ones I cited and expect the "typical" values to be, well, typical.
>
> I suppose I could spring for the $32 and order the ASTM  A36 spec, but
> I'm not sure that will really tell me anything. Maybe I'll have to swing
> by the library and see if I can find it there.
>
> I've been stubbornly trying to find a way to reliably weld the A36,
> maybe that's a bad choice. I figure I've "enough" success with it to
> make me think this can be done, and perhaps I was determined that I can
> find a way around my failures. But with little more than empirical
> experience, I'm probably setting myself up for a lot of frustration.
>
> As you noted, the cost of 1018 has me hoping that I could make A36 work.
> Since I'm not in production, my time at this isn't all that valuable (in
> terms of $$) but it may be time to give up on A36, and stop wasting time
> on it.
>
> **pn
>
> David Childress wrote:
>> In our group there is much debate about A-36.  I know from job
>> experience ( engineer in a tool & die shop) something about a36.  The
>> fact is that A36 is made from scrap and is junk.  Most of the specs
>> are max without min. or min. without max. and there are many metals
>> that are not mentioned  at all that may or may not be present.  Our
>> forgemaster really dislikes A36, but when a found a a distributor that
>> was willing to sell 1018 to us at his cost the cost still freaked most
>> of us out ( about 185% of A36 cost).
>>
>> I have been told that the lead and copper in A36 is what makes it hard
>> to forgeweld.  These are allowed for ease of machining, but due to the
>> processing of A36 they are not necessarily evenly distributed.  So
>> some places will forge weld and maybe 6" down the bar it will not weld
>> at all.
>>
>> I had a diemaker  tell me that once they got a piece of A36 that he
>> could not drill a hole thru.  some other Die maker cut the peice up
>> and found a piece of coil spring that had never melted at the end of
>> the attempted hole.  As another example my daughter made her first
>> knife ( letter opener) out of A36.  Being impatent as she always is (
>> 13 yrs old)  when she got it shaped she threw it in the quench tank.
>> We could not sharpen it (Hrc 68).
>> A36 is just like that.  It is good enough for most structural uses,
>> but you can never tell what it will be like.
>>
>> David Childress
>> Rocky Forge Blacksmith Guild
>>
>> On 2/11/09, Paul N <crosspein at sbcglobal.net> wrote:
>>
>>> OK, I've been reading that PDF that Frosty posted a couple weeks ago,
>>> and I'm about halfway through my first pass at it. (It will likely
>>> require more than 1 to understand it)
>>>  (It was this one: http://www.feine-klingen.de/PDFs/verhoeven.pdf)  And
>>> many thanks for posting that. It's just the kind of description I had
>>> been looking for.
>>>
>>> We should probably start "Frosty's Book Club" discussions, as I'm sure
>>> that there are things I think I understand, but that I've
>>> mis-interpreted. But that's a different story.
>>>
>>> I'm finding the "book" very enlightening, and not horribly difficult to
>>> read. (Although anything even approaching an hour at a time seems to
>>> stimulate the auto-nap response) I had taken a metallurgy class in
>>> college over 30 years ago, but studying to pass a class is totally
>>> different from studying to LEARN. So while I've been exposed to this
>>> stuff before, this time is different and enlightening.
>>>
>>> OK, now for my real question:
>>>
>>> I've occasionally been stymied while trying to forge weld with hot
>>> rolled A-36 steel, and since it occurred last night while I was
>>> demonstrating how to make a basket handle (using 6 pcs of 1/4" round
>>> A36) I thought maybe it's time to ask. I've made dozens of these, so
>>> it's not exactly a new process for me.
>>>
>>> My problem last night was that the person that asked for the demo had a
>>> pretty hollow (coal) fire, but I thought that I'm finally getting pretty
>>> good at this, so why not go ahead with it as is. The first weld, with
>>> all the pieces kind of loose, went off without a hitch. Welded nicely on
>>> the step of the anvil. But when I went to the other side, which I've
>>> always found easier as it's more stable, it didn't take. That's not
>>> really a problem in itself. I've been here plenty of times.
>>>
>>> What became an issue is, now even after correcting the fire, I can't get
>>> it to weld. After about 4 attempts, the ends are now hopelessly
>>> distorted and difficult to repair and I abandoned my demo in
>>> frustration. BTW, I was using straight 20-mule team borax as a flux.
>>>
>>> So, what happens to the metal? Does it pick up contaminants? Did it
>>> de-carburize (there was a little sparking, but not what I'd consider
>>> significant, and even if it did, wouldn't the lower carbon level make it
>>> easier to weld? )
>>>
>>> In the past, when I've had a failure like this with A-36, Usually end up
>>> cutting back the ends to get a successful weld, so I'm expecting that
>>> there has been some metallurgical transformation here. So I'm wondering
>>> if anyone knows what that change might be.
>>>
>>> Since I'm feeling a little more knowledgeable now, I've looked at  the
>>> chemical compositions of 1018 and A-36, and aside from the slightly
>>> higher carbon content of A-36 (about 0.25% C vs 0.18% C) there isn't all
>>> that much difference, chemically. Perhaps it's the inherent grain size,
>>> and with a little annealing the A-36 would behave better?
>>>
>>> (Using references from:
>>> http://www.benjaminsteel.com/Technical%20Data/A-36-properties.htm and
>>> http://www.geocities.com/haimanaua/htdocs/steels/1018.html )
>>>
>>> So, can anyone explain the differences in behavior in A-36 and 1018 when
>>> it comes to forge welding?
>>>
>>> thanks,
>>> **pn
>>>
>>>
>>>
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