On Sat, 24 Jun 2017 15:18:10 -0500, Terry Coombs <
snag...@msn.com>
wrote:
Let's hope it holds together. I'll bet it will be perfectly fine.
Although there is an entire mythology about welding 4130, it's really
relatively ductile, which makes it more forgiving that many people
think.
As I said in that article, the reason 4130 leads to so much
head-scratching is that it's *very* slow-quenching. In thin tubes,
which are almost always welded in the normalized condition, it can
wind up quench-hardened from welding. It actually will air-harden.
That's why it was two decades before TIG welding it was accepted. It's
only recently (the last couple of decades) that MIG welding has met
the approval of the "experts." Stick is similar.
Sections as thick as you're welding generally don't experience that
quench-hardening problem, but the quench characteristics can produce a
very confused HAZ. That's why the pre-heating and the slow cooling.
Every authority I've talked to over the last decade or so says that's
all it takes.
--
Ed Huntress