Noise while heating mild steel?

[Josh Bernbaum]

Sry, I don't know what to title this thread, hope it's not misleading. Just more of a curiosity for me than any sort of a problem, but I welded up a new pastorale (sp?) fork a couple months ago out of some mild steel to replace the old one I used for 10 plus years. This is for heating up plates of cane in the GH. The old one never made any noise when it got hot, but for some reason this new one started making a 'tink, tink, tink' sound (rapidly and repeatedly) after just one or two heats when the metal started heating up. My guess is it's some kind of expansion/contraction thing? What's even more interesting to me is that, although not fully stopped at this point, the noise has almost gone away after a couple months of use. (I don't use it everyday) So what do you think has happened to the steel after a couple months? Has something happened at a molecular level to silence what I'd been noticing? Again, just a curiosity, and to see what a possible explanation might be.

[Eben Horton]

Expansion. Have you ever been in an old house with steam heat and cast iron radiators?? They bang.

[Josh Bernbaum]

Well, yeah, I know what you're saying about radiators. But I'm still curious why it would stop making that noise after a while with my fork. Did the steel get 'seasoned' over time somehow? That doesn't seem to be the case with old cast iron radiators anyway, they keep making noise after years and years.

[Kenny Pieper]

Josh if your welds did not penetrate all the way through the joint it could be you are hearing the metal moving around in there.

[Pete VanderLaan]

I agree with Kenny

[Josh Bernbaum]

Okay, perhaps. But although I'm not an expert welder, I do feel like I've gotten good penetration on the thousands of welds I've done in my life. But no one's x-raying my welds, and I'm sure they wouldn't let me do welds on a nuclear submarine, so maybe you're right. However, even though I find myself not confident of most things in life, I would indeed sleep under something I welded without any reservations. What's still not explained by what you're saying though, is why did the sound stop after a couple months?

[Eben Horton]

I think the steel degrades with a bunch of heat cycles. I christened a new blow pipe last month and it banged on me. I was shocked

[Pete VanderLaan]

think more likely of abrasion. If two pieces don't normally touch when cold, that's where to start. Then heat the mass and it expands to the point where those pieces do touch, make a little noise passing each other but eventually, the passage abrades the contact, and it stops.

We see a similar effect in electrical contacts quite frequently. It's fine when it's cold but not once it expands. The electrical one we tend to notice more since it shorts things out.

[Kenny Pieper]

Yea what Pete says

[Lawrence Duckworth]

if your welds are as good as you say they are.. maybe it's the tuning fork shape

[Josh Bernbaum]

Haha, yup, tuning fork..
I'm liking the abrasion theory Pete, that does seem plausible.

[Marty Kremer]

Originally Posted by Eben Horton

Expansion. Have you ever been in an old house with steam heat and cast iron radiators?? They bang.

That's trapped air banging, not the cast iron.

[Eben Horton]

Originally Posted by Marty Kremer

That's trapped air banging, not the cast iron.

Prove it. I do t believe you

[Michael Ahlefeldt-Laurvig]

Wrong welding rods?

[Pete VanderLaan]

Originally Posted by Eben Horton

Prove it. I do t believe you

***
Have you never listened to your water pipes after an airlock in the lines?

[Marty Kremer]

Originally Posted by Josh Bernbaum

..... What's still not explained by what you're saying though, is why did the sound stop after a couple months?

Needs new batteries.

[Pete VanderLaan]

the scraping of the metal was making noise but that was abrading the metal as well. Eventually, there was no contact, thus, no noise.

[Franklin Sankar]

Jumbles.
Franklin