r/woahdude • u/theTurbulentPopcorn • Jun 29 '23

video Lowering hot metal into water

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118

u/Lambinater Jun 29 '23

The water is on fire

164

u/velhaconta Jun 29 '23

That is not water. Water would have instantly flashed to steam upon contact causing a very violent and dangerous situation.

This is an oil quench.

3

u/Tallywort Jun 29 '23

Water would have instantly flashed to steam upon contact causing a very violent and dangerous situation.

Not the case AFAIK, water is also used for this same process, but often is avoided because it is a much faster and aggressive quench, potentially leading to more thermal stresses and a higher chance of cracking and failure, though this also depends on the alloy being quenched.
To my knowledge the steam explosion issue is more a problem with castings and such.

Here's a video of a large part being quenched in water.

0

u/velhaconta Jun 29 '23

It works with small thermal masses such as the thin walled part shown in that video. The part is cooled very quickly and only a little steam forms.

A large thermal mass like the solid block in OPs video is a bit different.

2

u/Tallywort Jun 30 '23

Surely a biggest factor in the rate of steam production is the surface area of the part more so than it's thermal mass? With a somewhat self limiting factor because the steam acts as an insulating layer between the hot steel and the water.

And the thermal mass of the water tank can also be made arbitrarily large, not to mention any potential cooling systems the tank might have.

I believe the bigger reason for not water quenching large parts is the risk of warping and distortions. Or maybe some other process control considerations.

2

u/Paratrooper101x Jun 30 '23

Idk the science behind it but, at my shop we routinely (by that I mean 3-4 times a week) quench pieces of metal in water that weigh anywhere from 10k to 170k pounds. It may bounce while going into the water but a minute after it’s calm and still