New Steel: "as good as titanium, at a tenth of the cost"

[tumbler]

This could be interesting if the lab work is translatable to production.

http://www.economist.com/news/science-and-technology/21642107-alloy-iron-and-aluminium-good-titanium-tenth?fsrc=scn/tw/te/pe/ed/wingsofsteel

[paredown]

Perfect morning coffee reading...

Thanks

[weisan]

How'bout corrosion resistant?

[Kirk Pacenti]

That is pretty interesting, looking forward to reading more about the industrial scale tests... especially as it pertains to weldability.

[buddybikes]

Invest in POSCO? ...and JP Weigle frame saver...

[ceolwulf]

Very interesting, it sounds like it behaves very similarly to a metal matrix composite.

[Mikej]

Cheaper but how? I'D have to see actual parts and tubes and then we'll see. Labor is the real cost.

[EricEstlund]

Material costs when doing large construction projects (like high rise building and bridges) can be astronomical, and percentage variation can be huge for the cost of a project.

No so much with bike tubes.

The most expensive bike tubes have less steel then the cheapest ones, but as noted, the most work put into them as far as shaping, butting and heat treating.

If we see this trickle down into bike tubes it won't be as a way to make ti bikes out of steel for less money.

[BumbleBeeDave]

The story refers to a company that is going to test producing the new steel on an "industrial scale." That means thousands of tons. I would imagine the tubing companies for bikes--Columbus, etc.--would buy their several tons per year and that cost would be a relatively small part of their production cost.

The story says, "Dr Kim has produced a material which has the strength and the lightness of titanium alloys but will, when produced at scale, cost a tenth as much."

So the new material would be as strong as Ti and as light for a given strength, but Weisan is right--will it have the same corrosion resistance? And even if the resulting metal is 1/10 the cost of Ti, will it also be cheaper to build a bike of a certain weight and strength than it would be to make the same bike from carbon?

I would think that if this new material lives up to its promise in production cost, then it might be appropriate for certain high stress parts in cycling applications where its strength will give it an advantage over a carbon part of equivalent strength. But it might not be a cost-utility effective improvement for frames.

BBD

[abalone]

Back to the bike world of steel vs ti Tubing applications...

If you compare the bike frame weights of new steel (ie. the new Columbus, Reynolds, Deda, etc), you might be surprised that they are actually quite competitive with Titanium frame weight. In fact, there is much more customization of the tubing butt lengths and hence weight and ride quality that a custom framebuilder can to more easily with steel than with Ti.

New steel can be made to be lighter than new modern Titanium. Steel is available in very thin diameters for 35+mm oversized tubes. Over the years, the outside diameters of tubes have gotten bigger. The bad thing with Ti is that the wall thickness has remained the same, so you get a heavier Ti frame today compared to a Ti frame from years ago that doesn't have the super oversized tubing.

End result: Steel frames have gotten lighter through the years, while modern Ti frames have become heavier.

[Louis]

I'd be more interested in its mechanical and fatigue properties.

[zmudshark]

That is pretty interesting, looking forward to reading more about the industrial scale tests... especially as it pertains to weldability.

I found this comment from someone smarter than I am:

welding is a very popular manufacturing technique, but it can be a pain in the ass on something like this, since letting the metal melt and re-solidify ruins all the careful processing effort you put in to get the microstructure just right. You could end up with great big brittle precipitates in the heat-affected zone, which would make the weld way less durable than the rest of the metal- never a good position to be in, unless you like your products falling apart at the seams.

[DarkStar]

I found this comment from someone smarter than I am:

welding is a very popular manufacturing technique, but it can be a pain in the ass on something like this, since letting the metal melt and re-solidify ruins all the careful processing effort you put in to get the microstructure just right. You could end up with great big brittle precipitates in the heat-affected zone, which would make the weld way less durable than the rest of the metal- never a good position to be in, unless you like your products falling apart at the seams.
Wasn’t that the issue with the M4 metal matrix frames Specialized was selling in the early nineties?

[charliedid]

I'd be more interested to know if it will make me faster.

[mtechnica]

That would be ironic if you'd need lugs to build a frame with it, versus welding the material, the grain structure of the metal seems critical to its ability to flex and also bear high loads.

[abalone]

I found this comment from someone smarter than I am:

welding is a very popular manufacturing technique, but it can be a pain in the ass on something like this, since letting the metal melt and re-solidify ruins all the careful processing effort you put in to get the microstructure just right. You could end up with great big brittle precipitates in the heat-affected zone, which would make the weld way less durable than the rest of the metal- never a good position to be in, unless you like your products falling apart at the seams.


That was the argument back in the 80s and early 90s about why glued/bonded bikes, even steel and aluminum bonded bikes, had superior strength at the tube joints than welded bikes.

[oldpotatoe]

That was the argument back in the 80s and early 90s about why glued/bonded bikes, even steel and aluminum bonded bikes, had superior strength at the tube joints than welded bikes.

Also why lugs with steel and until the Reynolds(and now others), 'air hardened' steel, like 853, TT Plantinum, Columbus Nemo(?)...

[tumbler]

I'd be more interested to know if it will make me faster.

As with most bike upgrades, the answer is likely no (or maybe a negligible yes). We can always pretend though :)

[Coalfield]

The next unobtanium?

[ceolwulf]

Wasn’t that the issue with the M4 metal matrix frames Specialized was selling in the early nineties?


Very similar. In that case the ceramic particles suspended in the metal matrix tended to migrate away from the weld zone, leaving that as the weakest area.

[Scooper]

I splurged and forked over $32 for the Nature article.

The subject material is called "high-specific-strength steel", or HSSS. The first thing that struck me is that the claimed elongation (measure of brittleness/ductility) at the highest tensile strength condition is 20%, which is quite ductile; most steels used for bicycle frame tubing is in the 10% - 15% range.

The claimed density of HSSS is 6.82 grams/cubic cm, which really isn't that much lower than most other steels which are ~7.8 - 8.1 grams/cubic cm, so calling it "low density", while technically correct, could be misleading.

The chemical makeup of HSSS is interesting in that it contains no chromium. Stainless steels (corrosion resistant) by definition have more than 10% chromium by weight, so I doubt HSSS has much corrosion resistance.

Here's the chemistry of HSSS:

Weight %

Carbon (C) 0.86
Silicon (Si) 0.02
Manganese (Mn) 16.1
Aluminum (Al) 9.6
Titanium (Ti) 0.042
Niobium (Nb) 0.004
Nickel (Ni) 4.9
Iron (Fe) Balance

The article doesn't discuss weldability at all.

The claimed yield strength of HSSS is greater than 1 GPa. In comparison, Reynolds 953 stainless steel (Carpenter Technology Custom 455®) which has the highest yield strength of commonly used steels for bicycle frames, has a yield strength of 1.45-1.9 GPa (1450-1900 MPa), so the description of "ultrastrong" may be hyperbole.

Flow curves of HSSS show large ductility and phenomenally high strain hardening capability even at ultrahigh yield strength levels of over 1 GPa.

Still, I think this bears watching for further developments.