Decomposed > Is that believable? According to www.911research.wtc7.net, steel melts at a temperature of 2,777 degrees Fahrenheit, but jet fuel burns at only 1,517 degrees F. No melted steel, no collapsed towers.
Ahhhh . . .
But was it necessary to actually melt the steel supports? Or just get it hot enough to bend and warp such that the weight of the floors above would have been enough to cause the collapse?
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http://www.associatedsteel.com/does-heat-affect-steel/
Give or take a country mile; steels will melt around 3000°F. Whereas aluminum will melt around 1200°F. Short of those temperatures, you should not have to worry about your steel leaking off the shelf. Steels will begin to soften, however, at a wide range of temperatures based on their chemical composition and the thermal processing that got them to the current hardness.
Temperatures need not be extremely high to begin to lower the properties of the steel. Some of the very hard wear plates found in industrial applications (near diamond hard) will begin to soften at 280° to 350°F. You can cook a pork butt at 280°F.
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What grade of steel was used in the World Trade Center?
http://science.howstuffworks.com/engineering/structural/grade-of-steel-used-in-world-trade-center.htm
Even though the girders that comprised the twin towers wouldn't turn to molten steel in the jet fuel fire, they would certainly have weakened in the heat. In fact, one estimate says that they would have lost half of their strength at 1,100 degrees Fahrenheit (593.3 Celsius) [source: Popular Mechanics]. It's important to also note that other items would have caught on fire in the buildings in addition to the jet fuel, and could have contributed to higher burning temperatures.
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Yes, De, you covered the same thing . . . I got hung on the second paragraph . . .
Zim.
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