From shipping containers to skyscrapers to turbines, good old steel is still the workhorse of our modern world. Now, scientists are discovering new secrets to make the material better, lighter, and stronger.

Today a team of material scientists at Pohang University of Science and Technology in South Korea announced what they’re calling one of the biggest steel breakthroughs of the last few decades: an altogether new type of flexible, ultra-strong, lightweight steel. This new metal has a strength-to-weight ratio that matches even our best titanium alloys, but at one tenth the cost, and can be created on a small scale with machinery already used to make automotive-grade steel. The study appears in Nature.

“Because of its lightness, our steel may find many applications in automotive and aircraft manufacturing,” says Hansoo Kim, the researcher that led the team.
Bend, Don’t Break

The key to creating this new super-steel was overcoming a challenge that had plagued materials scientists for decades. In the 1970’s, Soviet researchers discovered that adding aluminum to the mix when creating steel can make an incredibly strong and lightweight metal, but this new steel was unavoidably brittle. You’d have to exert lots of force to reach the limit of its strength, but once you did, the steel would break rather than bend.

Scientists soon realized the problem: When creating the aluminum-steel alloy, they were occasionally fusing atoms of aluminum and iron together to form tough, crystalline structures called B2. These veins and nuggets of B2 were strong but brittle—until Kim and his colleges devised a solution.

“My original idea was that if I could somehow induce the formation of these B2 crystals, I might be able to disperse them in the steel,” he says. The scientists calculated that if small B2 crystals were separated from one another, then the surrounding alloy would insulate them from splintering.
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Hansoo Kim
B2 crystals (light gray) are dispersed in the aluminum-steel alloy (dark gray.)

Kim and colleagues spent years devising and altering a method of heat-treating and then thinly rolling their steel to control when and where B2 crystals were formed. The team also discovered that adding a small percentage of nickel offered even more control over B2 formation, as nickel made the crystals form at a much higher temperature.
More Super-Materials to Come?

Kim’s team has created the new metal on a small scale. But before it can be mass-produced, researchers must confront a tricky production issue.

This new metal has a strength-to-weight ratio that matches even our best titanium alloys

Currently, steelmakers use a silicate layer to cover and protect mass-produced steel from oxidation with the air and contamination from the foundry. This silicate can’t be used for Kim’s steel because it has a tendency to react with the cooling aluminum, compromising the final product. Before we starting building skyscrapers out of super-steel, they’ll have to figure out a way to protect the material out in the real world.

It’ll be worth it. The final product of all this tinkering “is 13 percent less dense compared to normal steel, and has almost the same strength-to-weight ratio compared to titanium alloys,” Kim says. That’s remarkable, but Kim insists that the method is actually more important than the result. Now that his results are published, he expects scientists to cook up a multitude of new alloys based on the B2-dispersion method.

Scientists Invent a New Steel as Strong as Titanium
South Korean researchers have solved a longstanding problem that stopped them from creating ultra-strong, lightweight aluminum-steel alloys.

I bet Uri Geller is shitting himself…
😀

Oh god no.. not more frame materials for people to fap over…

Will it be better than unobtanium ?

what about corrosion resistance? in my world that’s the real benefit of titanium over steel.

Isn’t 953 already stronger than titanium? Reynolds lists it’s “Ultimate Tensile Strength” as way higher than their titanium tubing. (I am not an engineer)

+1 jam bo, that next to last paragraph says there is a corrosion problem, though I am sure it is a an oxide layer rather than silicate layer as they say. Off to look up the Al to Fe galvanic gap.

And materials engineers the world over just spaffed their pants. I love the fact that we’re still discovering things about steel despite the fact that it’s been in use for ages!

Reynolds 953 has my vote

Sounds like frames are about to become laterally stiff yet vertically compliant.

Second paragraph, third line

flexible, ultra-strong, lightweight steel

I wonder how flexible?

Its still not a carbon Nanotube is it 😐

Coat it n Graphene – that will stop it rusting

zilog6128 – strength to weight rather than strength. Although I’m sure I’ve heard the same claim for some Reynolds steels.

Of course the issue is to get the same frame you’d have to make tubing tissue thin to keep the weight down and tube diameter up, and you’d find that in a practical scenario Aluminium will give you a better balance of weight/durability.

Still, interesting development which might be useful for more highly stressed components.

Isn’t 953 already stronger than titanium? Reynolds lists it’s “Ultimate Tensile Strength” as way higher than their titanium tubing. (I am not an engineer

Yes, Titanium isn’t all that strong in absolute terms. From the article it looks like they mean that the new material has a better strength to weight ratio.

Steel is generally stronger than titanium for a given tube, afaik – it’s just heavier.

Mostly Balanced – Member

I wonder how flexible?

£5 says it’s within 5% of 207 GPa.

Meanwhile in Sheffield, it’s 100 years since the invention of stainless. And is the UK celebrating one of the greatest engineering / science inventions ever? is it heck.

Meanwhile in Sheffield, it’s 100 years since the invention of stainless. And is the UK celebrating one of the greatest engineering / science inventions ever? is it heck.

Shouldn’t we actually be inventing new stuff rather than celebrating old stuff?

Shouldn’t we actually be inventing new stuff rather than celebrating old stuff?

Meh. I prefer steel to carbon.

“Meanwhile in Sheffield, it’s 100 years since the invention of stainless. And is the UK celebrating one of the greatest engineering / science inventions ever? is it heck.”
“Shouldn’t we actually be inventing new stuff rather than celebrating old stuff?”

I live in Sheffield and am a research associate at the local Uni’s materials science dept. I do a lot of research into ‘old’ iron & steel – and can confirm that the 100 years of stainless has been celebrated (& the Historical Metallurgy Society held a special conference up here to celebrate).

However, though my specialism is in older materials, I do think we should always be forging ahead (ahem), concentrating our main effort into developing new materials – oh, and it might not reach the mainstream news, but this IS happening in the UK (although I guess we could always do more if the Govt encouraged British companies to spend more on R&D!)

Shouldn’t we actually be inventing new stuff rather than celebrating old stuff?

We should be doing both.
My complaint is that we celebrate anniversaries of playwrights and painters and politicians, but the achievements which make a better worls remain unnoticed.

I live in Bristol and work at the local Uni’s purpose built composite materials development centre and can confirm that there’s plenty of effort and money being spent by both industry and the UK government on the development of new materials and their manufacturing technologies 😉

[/quote]My complaint is that we celebrate anniversaries of playwrights and painters and politicians, but the achievements which make a better worls remain unnoticed

Just cos some Northerner accidentally dropped some Chromium in a furnace we should make it a national holiday ?

😉

Meanwhile in Sheffield, it’s 100 years since the invention of stainless. And is the UK celebrating one of the greatest engineering / science inventions ever? is it heck.

Possibly because it wasn’t invented in Sheffield and it was going to be discovered around then anyway, see

Stainless steel discovery

zilog6128 – strength to weight rather than strength. Although I’m sure I’ve heard the same claim for some Reynolds steels.

Of course the issue is to get the same frame you’d have to make tubing tissue thin to keep the weight down and tube diameter up, and you’d find that in a practical scenario Aluminium will give you a better balance of weight/durability.

Still, interesting development which might be useful for more highly stressed components.

Yep, my reading was that they’ve developed a steel (alloy) with Relatively good Strength to weight properties, by overcoming a ~40 year old processing issue?

What the article doesn’t really go into is all the questions you’d actually ask when considering making a structure out of this stuff, what are it’s actual mechanical properties like? UTS? How Ductile is it? and as a manufacturing material How consistently can it be produced, considering it’s a steel full of diffused crystalline structures, can this new production method eliminate/minimise the risk of seams/fines big clumps of brittle material being formed and not detected? will I be able to get reliable cert’s from a Mill, have they processed this stuff before?

And how weldable is it? That’s the key thing with Titanium alloys (and why I personally don’t think it’s the best thing to make Bicycle frames from), Yes it has good general mechanical performance and Strength to weight, but fabricating with it is much more of a specialist task, and when it goes wrong it may not be obvious…
If this new steel can be welded like any other carbon steel and produce strong consistent joints, great! but can it?

In most industries Engineers like to use proven, well understood technologies/materials/methods of manufacture where they can to minimise the risk of failure, New materials are often left to niche businesses, motorsports, and people with a limited understanding of liability…

I do think we should always be forging ahead (ahem), concentrating our main effort into developing new materials

or get better at using what we already have around us in new and clever ways?

For example, making houses out of straw bales could reduce cost and energy consumption.

Interesting, I wonder what crazing welding process will have to be used to minimise the clumping of these B2 crystals?

and why I personally don’t think it’s the best thing to make Bicycle frames from

I was just thinking about this – surely from an engineering point of view carbon has to be the absolute best material?

Well carbon fiber already does make many (all!) top quality frames. If you mean elemental carbon, no that’s just daft.

Interesting.
We use a small amount of Ti in our industry (mostly because it is good with seawater) however it is expensive, and doesn’t offer big enough advantages over CuNi to warrant the additional costs.
As others have said Ti is difficult to weld (worse than CuNi) and its strength to weight properties are not really needed in our game (shipbuilding)

The other advantage Ti has over steel is it is much more stable as it warms up.
Steel starts ‘moving’ at about 30% of its melt-point, where Ti can be good for almost 70%, which is why it is used for things like turbine blades (in gas turbines – not wind-turbines)

Personally I’d not buy a Ti bike, as I don’t think it offers enough advantages over Ally or carbon to justify the costs + there seems to be a lot of quality issues.

Currently on the front page here http://singletrackworld.com/2015/02/is-the-future-in-korean-steel/

with the claim that it is easier to work with as it is a steel, which is a bit misleading as the op’s link above does not mention anything to do with weldability or machinability (unless I’ve missed it somewhere).

The Economist’s version of the story has this little beauty.

Steel is useful because it is strong and cheap. But it is also heavy. It has, therefore, always been useless for applications such as aircraft.

🙄

Freeagent CuNi is also liked for use in seawater service because it has antifouling properties. It doesn’t like high flow rates however.

Isn’t it a bit soon to be calling this the new messiah?

I mean, when you can but 10 tonnes of it, easily, cheaply and in any form factor, then yes, we can talk about using it instead of alluminium or Ti etc. Till then, nah! (and you can bet the people who have spent 10 years trying to get this new material to work won’t be giving away that knowledge for free……….)

(and it still won’t be as good as CF, as it won’t ever be a “uni-directional” material)

If it has the same Young’s modulus as regular steel, then if you make stuff super-thin out of it, taking advantage of it’s super-strength-to-weight-ratio, won’t it be super-flexible?