A question for all engineers and metallurgists: How can steel melt below its melting temperature?

Question

The melting temperature of aluminium is about 580 C (around 1076 F). Try to melt aluminium foil in your own open air fire, using kerosene or petrol burning in open air. eg. roll up some aluminium foil and expose it to open flames from your gas stove, or fire from a pan full of burning kerosene (any hydrocarbon fuel), where the only source of oxygen is open air.

Does the aluminium foil melt and start dripping like a liquid?

If so, your air fire is hotter than the melting temperature of aluminium (around 580 C, or 1076 F). Go on, try it ! In fact, paper fire burns at Fahrenheit 451 F or about 233 C. Even under strong winds, with lots of extra oxygen supplied, air fires rarely get hotter than 600 C, and can barely melt aluminium or glass.

Now the melting temperature of steel (iron+carbon) is 1532 C, or 2790 F.

Iron can only be melted in a specially designed blast furnace (where lots of extra oxygen is pumped into the furnace), or by using an arc or induction furnace.

Answer 1

Wow.  There's 5 minutes of my life I can never have back.

Answer 2

by cooid moulding proces

Answer 3

in electrical fuse link, they use brass strip with tin coated on the center. the overall melting point of brass is lowered because of the migration of molten tin into the brass. but in your question, i think you are referring to wtc

in the case of wtc the melting temp of the steel is lowered due to tremendous pressure created.  

example melting of iron at standard pressure is 1811K (1538C), but when the pressure increases to 100 - 300 GPa, the melting of iron is reduces to 1420 - 1470K. thats why below 5,100km at center core of the earth is a solid iron core while the outer core is a layer of molten iron.

for any demolition, when the explosive charges were placed  at the bottom of the building support coulomb the amount of pressure causes the whole building to collapsed like the video you shown.

Answer 4

A eutectic like sulfur will lower the melting point of steel, which is why they found so much sulfidation in the WTC core columns. They also have found high-tech thermate whose properties were documented only by DARPA and other Pentagon friendlies prior to 2001.

Answer 5

Let's see... You have a PhD and teach materials engineering at University level.  And you get a lot of material from YouTube and don't seem to be aware of coal-fired furnaces that can melt iron.  Yikes!!!

Answer 6

it is not the temperature but the amount of produced heat that allows melting - it is accumulated inside the material and rises it's temperature, regardless of paper combustion temperature.

Also, thin foil gets heated faster than massive slab of material, thus transferring heat throughout it's "volume" and rising temeprature up to the melting point. It is simple as that...

By the way - paper IGNITION point is 450F - not it's combustion temperature (which is much higher, depending on it's components).

Answer 7

Go to Saugus MA, and visit the iron furnace from the 1700's they have there.

A furnace using coal that melts iron ore and produces molten iron. No oxygen, just air.