On Thu, 08 Oct 2015 13:59:42 -0500
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:
I got in a hurry on a job, and had to run 10-mi to the scrapyard for some
heavy 4" angle, rather than driving the 80-mile round-trip to the only
distributor around. It ended up being some 9.8lb/ft 4x4 angle (so,
pretty heavy angle, 3/8" flanges).
They had only one piece that would suit: It was obviously hot-dip
galvanized (no problem in itself), had cut ends (after galvanizing), and
had sat in the yard, in the weather (wet) for weeks to months before I
rescued it.
It welds perfectly with mild steel MIG wire and CO2. Did some test welds
before comitting to all the cutwork I needed to do on it. It made clean,
smooth, STRONG welds that I could not break even bending the piece at the
weld... it just bent there, being just a line-weld, and thinner than the
flange.
'Funny thing, though, none of the few gouges and dings in it had even a
trace of rust. Neither did the cut ends ??? I did some fresh cuts,
exposed them to overnight dew and 85F temps (just to see), and not a SIGN
of corrosion.
Hmmm... I'm not familiar with the alloy. It's obviously NOT any of the
3xx series stainless I often work with, and although those will braze,
and will weld Eh..OK with mild steel wire, they don't usually produce as
strong a weld as the base metal. It's also as strongly magnetic as A36
would be.
My experience has been that when heavily galvanized members like this
show up in the scrapyard, they've often come from power company pull-
downs.
Has anybody worked with a steel that demonstrates these properties? I
think I'd like to find more of it! G
I've heard of smearing when galvanized sheet steel is cut with a shear.
Which I'm sure you have too.... From a little bit of searching I found
this that may explain it some:
http://www.astm.org/SNEWS/APRIL_2006...ide_apr06.html
Should make more sense to you with your background... but the gist I
get is that even though you exposed untreated metal the treatment
still close by is somewhat protecting it (shrug).
--
Leon Fisk
Grand Rapids MI/Zone 5b
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