New Way to Make Lighter, Stronger Steel -- In a Flash

[GreyGeek]

http://www.eurekalert.org/pub_releas...-anw060911.php

[wizard10000]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

Yeah, but it ain't transparent aluminum.

[img width=400 height=247]http://cdn.gajitz.com/wp-content/uploads/2009/11/scotty.jpg[/img]

[ardvark71]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

Yeah, but it ain't transparent aluminum.

[img width=400 height=247]http://cdn.gajitz.com/wp-content/uploads/2009/11/scotty.jpg[/img]

How quaint

[dibl]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

Kind of amazing to think there's anything new in steel making, in 2011.

[MoonRise]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

Yeah, but it ain't transparent aluminum.

[img width=400 height=247]http://cdn.gajitz.com/wp-content/uploads/2009/11/scotty.jpg[/img]

+1.... Agreed!

[blobfish]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

Cola further claimed that his steel could be drawn – that is, thinned and lengthened – 30 percent more than martensitic steels without losing its enhanced strength.

I am taking this to mean that the stock can be run through the heat treat process and then run through the stamping process. If that is true it will be a great improvement, but if they want to sell us on some heat treat process after stamping....RUN!

[GreyGeek]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

Kind of amazing to think there's anything new in steel making, in 2011.

That's what I thought, which is why I found this article so interesting.

Imagine being able to replace all those specialized uses of Titanium (because it is so expensive and difficult to process) with this kind of steel, which would be better, and more economical.

[woodsmoke]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

Very nice article GG, I'll incorporate this in the new Physical Science class that I'm teaching this next fall.

woodsmoke

[erchie]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash



if they want to sell us on some heat treat process after stamping....RUN!


[/quote]

Why?

[blobfish]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

getting acceptable sheet metal parts out of a stamping die for automation is hard enough.

[woodsmoke]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

I remember when the first really big onslaught of Japanese made roll sheet steel for things like the bottoms of t.v. cabinets, refrigerator doors, etc. first hit the U.S. markets in the 70's.

They just had a "different" way of annealing the metal, and when a stamp hit the metal it would tear the metal instead of "forming" it.

This stuff may be "harder" but that does not mean that it is necessarily amenable to being worked without an inordinate cost in new equipment.

it could woik or it might not as Curly used to say!

woodsmoke

[GreyGeek]

Re: New Way to Make Lighter, Stronger Steel -- In a Flash

From the article:

Though the typical temperature and length of time for hardening varies by industry, most steels are heat-treated at around 900 degrees Celsius for a few hours. Others are heated at similar temperatures for days.

Cola's entire process took less than 10 seconds.

He claimed that the resulting steel was 7 percent stronger than martensitic advanced high-strength steel. [Martensitic steel is so named because the internal microstructure is entirely composed of a crystal form called martensite.] Cola further claimed that his steel could be drawn – that is, thinned and lengthened – 30 percent more than martensitic steels without losing its enhanced strength.

If that were true, then Cola's steel could enable carmakers to build frames that are up to 30 percent thinner and lighter without compromising safety. Or, it could reinforce an armored vehicle without weighing it down.

"We asked for a few samples to test, and it turned out that everything he said was true," said Ohio State graduate student Tapasvi Lolla. "Then it was up to us to understand what was happening."

Cola is a self-taught metallurgist, and he wanted help from Babu and his team to reveal the physics behind the process – to understand it in detail so that he could find ways to adapt it and even improve it.

He partnered with Ohio State to provide research support for Brian Hanhold, who was an undergraduate student at the time, and Lolla, who subsequently earned his master's degree working out the answer.

Using an electron microscope, they discovered that Cola's process did indeed form martensite microstructure inside the steel. But they also saw another form called bainite microstructure, scattered with carbon-rich compounds called carbides.

In traditional, slow heat treatments, steel's initial microstructure always dissolves into a homogeneous phase called austenite at peak temperature, Babu explained. But as the steel cools rapidly from this high temperature, all of the austenite normally transforms into martensite.

"We think that, because this new process is so fast with rapid heating and cooling, the carbides don't get a chance to dissolve completely within austenite at high temperature, so they remain in the steel and make this unique microstructure containing bainite, martensite and carbides," Babu said.

Lolla pointed out that this unique microstructure boosts ductility -- meaning that the steel can crumple a great deal before breaking – making it a potential impact-absorber for automotive applications.