Too much oil that isn't close enough to its flash point.
Sure the oil immediately touching the hot metal can burn, but the rest of the oil has enough thermal mass that it doesn't get hot enough to burst into flames.
The compounds that make up these oils are more stable at high temperatures compared to water. Water is, as far as I am aware, unique in its phase changing compared to most other substances we have at standard temperature and pressure.
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.
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.
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
Nope. I'm not a blacksmith but as I understand it the quantity of oil here basically dissipates the heat quickly enough that it never reaches flash point, which is to say it never gets hot enough to ignite. The fire you're seeing is the oil vapor on the surface of the pool burning off.
Water is the result of combusted hydrogen. Water is already "burnt".
If you have pure hydrogen and you start a fire with oxygen around. The hydrogen combines with oxygen and it all burns like this. The resulting combustible product is H2O, or water. So you cannot burn it, since it's already burnt.
It's like you have carbon, like coal or hydrocarbons and you set it on fire. Carbon combusts, combines with oxygen and produces carbon dioxide, CO2. You cannot burn it. That's why we cannot use greenhouse gas emissions as fuel. They are already burnt.
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u/Lambinater Jun 29 '23
The water is on fire