Stainless steel treatment for reduced friction on ice...Thoughts?? 2

[MeridianDesign]

Hello!

First post on this very cool and helpful forum. I'm looking for some creative feedback on an issue I'm currently researching. So here we go, any feedback is greatly appreciated.

I am currently researching the relationship between steel blades and ice in the sport of bobsleigh. I've already tested using different compositions of steel, some harder, some softer, etc. For this particular experiment I'm just using stainless steel. So here is the question, can anyone think of any methods for treating or polishing the steel to reduce friction or introduce a lubricating effect between the steel and the ice?

Whatever the treatment is it must obviously possess some sort of water resistance (sliding on ice), chemical resistance (contact with acetone and citrus so it must be able to withstand these chemicals as well). I've considered using certain lubricants, waxes, and embedding chemicals in the pours of the steel but I am way outside of my expertise the area of manipulating steel in this way.

So, if anyone can think of any chemicals, treatments, or polishing techniques to make this bobsled go a little faster down the ice track please post them.

Hopefully this unique post has made someone smile haha, have fun!

 

[EdStainless]

In short, harder is better.
I don't recall about surface finish, but there is such a thing as too smooth.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[MeridianDesign]

I absolutely agree. I've read several articles which confirm that the harder steel will be faster on ice. Here is the tricky part, the blades for the bobsled can only be made from a certain type of stainless, its partly a rule thing and partly what the manufacture's choose to use. So unless there is someway to change the composition of the steel and make it harder I think the key to this problem lies in correct methods for polishing, or finding a versatile lubricant. I had heard about a ion immersion technique which could harden the steel but again this is way beyond my expertise.

 

[swall]

It would be helpful to know what grade of stainless you are working with.

 

[1gibson]

Check into carbon diffusion coatings (kolsterizing is one.)

 

[TVP]

The ion immersion treatment is likely to be Kolsterising, as 1gibson mentioned above. Here is a link for more information:

http://www.kolsterising.bodycote.com/

 

[salmon2]

I did a lot of research work about friction/lubrication in metal working before. Some basic informations have to verified first IMHO, such as what is the temperature at the interface given the speed, what is the lubricant really (is it water or none?), what is the ice hardness and roughness, etc. These informations will help to understand where the friction exactly is coming from and then improvement can be made more specifically.

Without knowing your application, I think the hardness of your blades won't matter much at a microscopic viewpoint because it will be always harder than ice. But if it helps I think it is because with greater strength, aka hardness, your structure is stiffer then you can get more uniform pressure at interface, instead of localized higher pressure right below the center of weight (will shift back or forth depending on acceleration) if structure is not stiff enough. Therefore thickenint your blades may be a quick solution. Just a "maybe" because you have to consider contact area, structural weight, cost, etc as well.

Regarding hardness, smoother finish can prevent harder surface from plowing softer surface; but two really smooth surfaces will tend to stick together and a little bit rougher surface can trap lubricant better. This goes back to what is the lubricant between ice and steel blade? If lubricant exists, what is the pressure at the interface? If pressure is low and there is no direct contact between blade and ice, then all friction is coming from shearing resistance of lubricant. If pressure is high and there is direct contact of ice/blade, this is another source for friction and has to be considered accordingly.

I may have written too much, but couldn't help

 

[tomwalz]

We were peripherally involved in this a few years ago. As I recall the stainless steel runners run on water and not ice. It has been a long time and is not my field but I think it was both pressure and friction.

This would suggest a design that created water as s soon as possible would be advantageous. Or, perhaps, a design where the runners penetrated through the water and rode on ice.


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[MeridianDesign]

Very interesting contributions everyone!

You've certainly given me a lot to think about and research.

I should have mentioned this before but the steel is 304L stainless and that unfortunately cannot be changed, so however I intend to speed up the steel it must be done with the 304L.

With regards to the smoothness of the steel and lubrication I agree that polishing too much does seem to reduce the effectiveness of a lubricant. Does anyone know of a good lubricant which would be resistant to water, acetone, and long lasting enough to survive 60seconds on ice at speeds above 80mpH?

 

[MeridianDesign]

I agree with what TomWalz mentioned above. It seems it is advantageous to create a situation where there is a layer of melted ice (water) between the steel and the ice. Heating the blades isn't an option because it too rapidly melts the ice at the start and quickly cools down. If you could achieve the slight melt and layer of water between the blade and the ice during the entire run (which is generally 1200-1500m over approximately 60s, reaching speeds of around 80mpH) that would surely result in some very quick times.

 

[MeridianDesign]

One additional thought as well. I had heard rumours of a technique used by the german team where the steel was heated and then dipped in a vat of wax. The theory was that during the race the friction between the 304L would heat the steel, releasing the wax from the pours. The waxy surface would presumably be faster than the steel surface alone. This however requires are far greater understanding of the steel then I have haha

 

[1gibson]

So just to be clear, the only rule is that it needs to be 304L?

You can dip it in wax, heat it, soak it in holy water... In the absence of any apparent rules/regulations:

1) Can you line the bottom with another material? Potentially including a substantial layer of frozen lubricant (wax, heavy grease?) that would be expended during the run?
2)Can you file grooves in the sides to retain a small volume of wax or other lubricant that would flow down as it melted, onto the blade?
3) Less visible, can you drill holes in the side for lubricant to seep out of?
4) Does the bottom of the rail have to be flat? Can you alternate between lubricant 'reservoirs' and contact patches, localising the heat input from friction and melting a lubricant that is stored in the center of the rail ("gun-drilled" style)?
5) Can you have an active lubrication system? Force lube grease reservoir that is expelled based on operator weight (hydraulic reservoir underneath the seat cushion)

List can go on and on, with very little to do with metallurgy... Kolsterizing or other surface hardening (shot peening - may work in conjunction with the wax dip) are the only "real" answers I think.

 

[arunmrao]

"Least friction on ice, with good heat transfer
thread330-118794"


I could search this thread on a similar topic in this forum. There was yet another thread,I recall,which had a long discussions and was interesting to understand the demands for a good material. ( I come from a place ,where it does not snow).



_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[IRstuff]

Seems to me that the blade bottom morphology would have a significant impact on performance. Tire manufacturers spend thouands of manhours trying to eliminate hydroplaning, but it seems here, we want the opposite, so there must be something that can aggravate hydroplaning.

However, that's not the whole story though, is it? Most bladed sports require razor-sharp and hard edges, and I would think that sleds are no different. Being able to precisely control a sled trajectory down the chute is sometimes more critical than just about anything else. Note that the sides of the blades will also be important to performance.

Finally, ice conditions can drastically affect performance. Slush kills performance, and in those conditions technique and skill are everything.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[arunmrao]

I can recall,we commonly agreed to suggest a hardened steel ( D2? )with carbide inserts ,to retain the sharpness and accuracy of the profile.

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[MeridianDesign]

All very good points which have been raised here. The basic problem is in order to work within the rules you must use the pre-made blade which is the 304L stainless. Any modifications must be made discretely so drilling holes to release wax or some kind of lubricant would be a brilliant idea but unfortunately not feasible. I think Kolsterizing is a great idea that show's a lot of promise, and I will certainly research it further.

Does anyone know who I could contact about researching the heated wax dip further? It sounds like a good idea but I wouldn't even know what industrial application would normally employ that technology.

Finally can anyone recommend a lubricant which is water resistant, acetone resistant, and works well for the conditions (cold weather, water, etc etc)? Perhaps there is something I can buy or quickly have a chemist make up for me?

Thanks for all the excellent input so far. If these ideas result in a gold medal winning blade then I'll have to make sure the athletes mention the contributions from Eng-Tips.com users are responsible for the success! haha.

 

[IRstuff]

"Does anyone know who I could contact about researching the heated wax dip further? It sounds like a good idea but I wouldn't even know what industrial application would normally employ that technology. "

Just go to your local ski shop. Or your local luger(?). They already know all there is to know about waxing for ice. In fact, there are probably dozens of waxes available on the market for skiing, skating, and luge, and for different ice conditions. Just be aware that no aftermarket applique will survive more than a couple runs.

It's a little perturbing that you don't know about waxing. The East Germans and Russians have probably spent tens of millions of dollars on the subject of blades and waxing, and THEY are your competition.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[tbuelna]

I took a look at the bobsled rule book for the FIBT, and the regulations for runners are very strict. There is a standard material and runner, as well as hardness limits. The rules also state no materials may be added in any way. I would interpret that to include coatings.

A carefully controlled surface texture may be helpful for reducing friction. I remember reading a few years back that the America's Cup boat hulls were given a very carefully controlled surface texturing that promoted adhesion of a surface boundary layer of water. The theory apparently being that water sliding against water produced less friction than water against the hull material. I would imagine that the same principle would apply to the sled runner surface and a water film.

Terry

 

[MeridianDesign]

Terry, that is a very interesting point about the haul's of ships. For the races you're right, the guidelines are very strict, the purpose of this thread was to develop ways in training to achieve higher speeds to teach the pilots to react to steering a few kms/hr more. So the things discussed here aren't really for the races, more for the training aspect, so we can be a little more flexible in terms of how the steel is manipulated. We'd just like to keep the equipment as close to race day as possible, so totally redesigning a blade with different material or what have you isn't really feasible. If anyone has anymore info on the yacht haul coating I'd love to hear more about that.

IRStuff, I wonder if using regular ski wax and an iron to heat the steel would have it penetrate the pours deep enough? In luge the steel is totally unregulated but in bobsled as Terry pointed out there are a lot more regulations, so in the bobsled world we are a little further behind the luger's in terms of techniques for making quick blades.

Does anyone know of a lubricant / chemical compound that would be a good choice for this application? Something with some chemical resistance as well as water resistance? and a good lubricant for sliding?

 

[arunmrao]

There have been reports of some concern regarding Kolsterizing. Essentially,they report of inconsistent,and layer thickness defects. You might want to check more about it,before adopting them.

You may also explore a process popular in Europe by Prof Somers and his group.

http://www.expanite.com/Technology.php.

Hope it helps.

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year