No. We would see a completely different microstructure. Thermite doesn't work by intergranular attack. It works by transferring the heat to the material to be melted. We would also expect to see large quantities of iron, in the form of alpha ferrite, on the surface of the sample. We don't see that.
thermate?
They said the type of attack was similar.
similar even at 150C more than what they said the wtc 7 steel experienced. could they get similar results at 950C? how high can we go and for how long or short to see "similar" results.
As long as the steel is solid, in this case the austenite phase, then a solid state diffusion mechanism will be observed. I can see what your angling at but it's incorrect.
solid state diffusion occurs on cooling as far as i can read. the austenite stays solid for many more degrees than 950C.
incorrect how?
Your making an elementary mistake with regard to sulphur concentration. I'm not even sure I can explain this in laymen's terms. There is a liquid that contains Fe, O and S that has been formed by internal sulphidation and oxidation via solid state diffusion.
there still has to be that much sulfur in the eutectic if the 950C is correct.
via solid state diffusion? please explain since the paper states:
"Sulfidation in the solid state into the austenite grains occurs much slower and is observed on cooling as a gradient of precipitated sulfides and oxides or oxidized sulfides with many of these particles containing silicon."
they say on cooling...
As the liquid penetrates the grain boundaries sulphur from this liquid will diffuse further into the steel lowering the concentration of sulphur, however, sulphur from the atmosphere will continue to diffuse in the liquid. Sulphur is far more readily diffused into a liquid than a solid. Get a lump of ice and put some sugar on top. Does the sugar dissolve in the water? Now melt that ice and do the same thing. Now heat the water up and do the same thing. More sugar will dissolve in hot water than cold than solid ice.
which begs the question, how much sulfur would one need to "corrode" 15.9mm of a36 steel in just 8 days!!
You don't need a concentration of 31% S in a gas to form FeS or Fe-O-S. You also aren't considering the effect of CO/CO2 or of alloying elements etc. This is not a simple science, it's damn complicated.
but you do need that much sulfur in the "slag" at 950 like they state for there to be a "eutectic"? and a continuous supply of it.
Again the reason for using FeS powder at that temperature is to demonstrate the effect. It's got nothing to do with office furniture or how much "metal can be dissolved". It's a proof of concept experiment.
and that is exactly what type of experiment needs to be done to show that a "eutectic" can form from office material to form the "eutectic" that can attack steel like the wtc samples!!!!
On slide 46 it's self evident, but then of course I know what I'm looking at. In my first job one of the tasks was ensuring that the plating process was carried out to the relevant specification and therefore measurement of the copper and nickel layers was required. The copper strike is the "pinky-orange" layer below the Ni layer (see below). It's fairly standard practice to put a copper strike or flash on before nickel plating.
considering some parts of that beam are 95% gone, how you can tell that is amazing!! they didnt show what parts were scanned. they just said some of the most corroded parts so im assuming the parts that were almost gone.
Again you misread what I posted. I said that the experiment with the FeS powder served a purpose for a specific time and budget. It was done for a very quick test to look at the effect of FeS on steel at that temperature. It was not designed to mimic an office fire or burning in the rubble pile.
all he was doing was playing with eutectics and steel. he wasnt trying to figure out how an office/debris fire could cause a eutectic to form to attack steel.
No. We would see a completely different microstructure. Thermite doesn't work by intergranular attack. It works by transferring the heat to the material to be melted. We would also expect to see large quantities of iron, in the form of alpha ferrite, on the surface of the sample. We don't see that.
thermate?
They said the type of attack was similar.
similar even at 150C more than what they said the wtc 7 steel experienced. could they get similar results at 950C? how high can we go and for how long or short to see "similar" results.
As long as the steel is solid, in this case the austenite phase, then a solid state diffusion mechanism will be observed. I can see what your angling at but it's incorrect.
solid state diffusion occurs on cooling as far as i can read. the austenite stays solid for many more degrees than 950C.
incorrect how?
Your making an elementary mistake with regard to sulphur concentration. I'm not even sure I can explain this in laymen's terms. There is a liquid that contains Fe, O and S that has been formed by internal sulphidation and oxidation via solid state diffusion.
there still has to be that much sulfur in the eutectic if the 950C is correct.
via solid state diffusion? please explain since the paper states:
"Sulfidation in the solid state into the austenite grains occurs much slower and is observed on cooling as a gradient of precipitated sulfides and oxides or oxidized sulfides with many of these particles containing silicon."
they say on cooling...
As the liquid penetrates the grain boundaries sulphur from this liquid will diffuse further into the steel lowering the concentration of sulphur, however, sulphur from the atmosphere will continue to diffuse in the liquid. Sulphur is far more readily diffused into a liquid than a solid. Get a lump of ice and put some sugar on top. Does the sugar dissolve in the water? Now melt that ice and do the same thing. Now heat the water up and do the same thing. More sugar will dissolve in hot water than cold than solid ice.
which begs the question, how much sulfur would one need to "corrode" 15.9mm of a36 steel in just 8 days!!
You don't need a concentration of 31% S in a gas to form FeS or Fe-O-S. You also aren't considering the effect of CO/CO2 or of alloying elements etc. This is not a simple science, it's damn complicated.
but you do need that much sulfur in the "slag" at 950 like they state for there to be a "eutectic"? and a continuous supply of it.
Again the reason for using FeS powder at that temperature is to demonstrate the effect. It's got nothing to do with office furniture or how much "metal can be dissolved". It's a proof of concept experiment.
and that is exactly what type of experiment needs to be done to show that a "eutectic" can form from office material to form the "eutectic" that can attack steel like the wtc samples!!!!
On slide 46 it's self evident, but then of course I know what I'm looking at. In my first job one of the tasks was ensuring that the plating process was carried out to the relevant specification and therefore measurement of the copper and nickel layers was required. The copper strike is the "pinky-orange" layer below the Ni layer (see below). It's fairly standard practice to put a copper strike or flash on before nickel plating.
considering some parts of that beam are 95% gone, how you can tell that is amazing!! they didnt show what parts were scanned. they just said some of the most corroded parts so im assuming the parts that were almost gone.
Again you misread what I posted. I said that the experiment with the FeS powder served a purpose for a specific time and budget. It was done for a very quick test to look at the effect of FeS on steel at that temperature. It was not designed to mimic an office fire or burning in the rubble pile.
at 1100 and not the 950 like they state the steel reached.
As for Sissons, good luck to him. I sure as hell wouldn't want to write the brief for that experiment! When you look at what he's potentially studying (see below - taken from your link) then he's got an almost infinite set of conditions to test. How do you recreate a unique, localised set of conditions you know very little about? There's a decade of work there.
at least he understands that one needs to look at the office/debris fire that is suppose to cause the eutectic in the first place.
Sorry I was wanting something a bit more detailed than that. It's not that simple and it doesn't take into account the myriad of complex factors that need to be detailed and accounted for. Anyone can say "burn stuff" but that isn't going to help.
hummmmmm...office/debris fire......8 days......15.9mm of a36 steel gone....
I'd like more information on these two specific pieces of steel examined. We can't say exactly when they were removed nor do we know where in the pile they were found. Either way it still doesn't point to thermate being the cause.
wouldnt we all.
Argument from personal incredulity.
Prove that bolded statement please or cite a paper.
and you can show a paper that states that corrison of 15.9 mm in just 8 days or one inch to razor thin in just 8-18 days?
