Steel rims in fires

G'day,

Since this is like the only forum I post on, I thought I'd ask here. You may or may not have heard about the bush fires in Victoria, Australia. Anyway my Dad's place was taken (along with the neighbours). Including some really cool stuff like a Suzuki Sierra 4x4.

Basically my question is, is it possible to use (steel) car rims if they have been through a fire? The fires are hot enough to split bricks, and melt aluminium so I'm not sure. It would be nice if it is safe as they're expensive rims. Here is a pic anyway:



Thanks
Zac

I wouldn't - if it's that hot (Al melts around 6-700'C), it's likely to have changed the properties of the steel (made it softer for example).

--
Mats

Sorry to hear about your father's loss of property.

As for the rims, they weren't engineered for use with fire damage in mind, so play it safe and don't use them.

I'm sorry for your dad's loss of his home. I've been tracking this on the news here in the USA. Somebody is a real asshat.

I hope nobody was hurt, and that your dad had insurance.

As for the rims, heat alters the structure of most metals including steel. Depending how hot the fire got, how fast it got hot, and how fast it cooled down, those rims could be brittle, have internal cracks, be invisibly deformed...

Maybe nail them to the fence to remember the event, but I certainly wouldn't use them for anything.

EDIT: I suppose you could take them to a metal shop and have them checked out with an X-ray or a magnetic crack finder followed up with some heat treatment, but that would cost money of course.

If the tires seal properly and you can get the tires to balance without huge weights, they are fine. I wouldn't use them for racing at high speeds, but they are perfecly safe for highway speeds or below. I like the theories people have about it changing the properties of the steel, but sorry to say rims don't go through heat treating to begin with, so they can't be annealed. In fact they they don't make rims out of steel, steel is unsafe, they are cast iron.

Thanks for the kind words.

Yes it probably isn't a good idea to use them, of course it is insured but as always it's worth more than they'll give you. It wasn't a high speed car anyway, topped out at 70kmh / 43mph. We even lost our pet (wild) Koala, but I won't post a photo of him

Thanks again, and lets hope they catch the arsons eh!

Well, by high speeds I mean 140 mph and up. As I said, if they hold air, they are fine. Cast iron doesnt anneal, so the heat itself cant effect them unless it deformed them. If they are deformed they wont hold air. At very high speeds, 140+ mph, small deformities, which arent unsafe at normal speeds could cause issues, so again, dont take them out racing, but highway speeds are perfectly safe, and if you get killed because of them you have my permission to punch me in the nuts.

I have those same rims on ym truck

Originally Posted by abachler

Cast iron doesnt anneal

But cast iron in a dirty fire does. Carbon soot from the fire can actually diffuse into the surface of the iron, turning it (the topmost layer, that is) into steel, which then becomes brittle if quenched (as would happen while putting out a fire).

This is actually how they discovered steel in the first place.

I would say the metal in the rims has certainly gone through some changes due to the heat. To suggest that it has not defies every piece of metal I've ever worked with. I'm sure the rims are most likely out of round somewhere if even by a few thousandths but it would be enough to make a huge difference in the ride, the wear pattern of the tires, the strength of the alloy, and the overall structure of the rim.

To measure a rim you need some type of depth gauge affixed to a stand. Place the depth gauge end on the rim and slowly rotate the rim. The measurements should not differ by much. I used this as an auditor several times to check if the rims on the unit I was auditing were out of round. Often times I would get a unit that had an extremely rough ride. Most digital calipers have a depth gauge on one end of them that you can use. To determine if they are out of round you must get a hold of the OEM specs for the rims. All rims will have acceptable tolerances and you will also have to account for any normal wear and tear on them to this point. They should also have an absolute safe maximum acceptable tolerance and if they are out I wouldn't use them.

I like the theories people have about it changing the properties of the steel, but sorry to say rims don't go through heat treating to begin with, so they can't be annealed. In fact they they don't make rims out of steel, steel is unsafe, they are cast iron.

Not all rims are cast iron either. In fact I would say that 90% of them are not. Most factories are using some type of alloy in the rims to make them both cheaper to make and lighter thus improving fuel economy. My poor alum. alloy rims would definitely not make it through a fire. Steel rims would certainly become brittle and any alloy would also experience some type of change due to the heat and sudden quenching. Even if the rims have been heat treated to make them stronger this also makes them more brittle. Heat treating was common practice on several of our components and it made the metal super hard but also super brittle. Those rims have definitely been heat treated now and through an out of control process.

Let's just say as a former auditor I would not allow them past me knowing what they had been through and I certainly would not entrust my life nor my family's life to them.

Here is some information related to re-manuf. rims that might apply to your situation.
http://news.carjunky.com/car_safety/...s-cdh100.shtml

If they are out of round enough to be a safety hazard, they will not hold air, AND they will require far more than the normal amount fo weight to bring them into balance, hence my assertion holds.

And obviously if they are alloy rims they are worthless, but the OP stated they were 'steel' which since noone makes steel rims, means they are cast iron. If they got hot enough to change the surface to high carbon steel, they would have melted, because the rate of crabon diffusion is insignificant below 1300K

http://www.springerlink.com/content/r57777658462t1u1/
http://cat.inist.fr/?aModele=afficheN&cpsidt=3559203

At most you would end up with a surface layer of very mild steel, which is neither brittle nor ductile

http://en.wikipedia.org/wiki/Carbon_steel

If they are out of round enough to be a safety hazard, they will not hold air, AND they will require far more than the normal amount fo weight to bring them into balance, hence my assertion holds.

This does not fit with my experience as an auditor of heavy machinery. I have had several rims that were completely out of spec and yet had no trouble holding air.

Your statement about heat treating is also incorrect. Many types of rims do undergo heat treating at the factory where they are produced.

And you are making quite a few assumptions here about the original structure of the rim and what the rim is composed of.

I like the theories people have about it changing the properties of the steel, but sorry to say rims don't go through heat treating to begin with, so they can't be annealed. In fact they they don't make rims out of steel, steel is unsafe, they are cast iron.

I would say some wheels are indeed made of steel but most are alloys. The only cast iron wheels I can find on the net are for train cars and industrial vehicles.

Steel wheels:
http://www.carpartswholesale.com/cpw/nissan~wheels.html
http://www.steel.org/AM/Template.cfm...entDisplay.cfm
http://www.autosteel.org/AM/Template...ontentID=25683

Alloy wheels with heat treat
http://www.techeblog.com/index.php/t...e-alloy-wheels

Article on automotive wheels:
http://www.just-auto.com/article.aspx?art=1210&type=2

Differences in steel and cast iron:
http://en.wikipedia.org/wiki/Steel

Steel grades:
http://en.wikipedia.org/wiki/SAE_steel_grades

On the units I audited cast iron was only used for the main frame components, wheel housings, and differential housings. It had distinctly different surface properties and specs as opposed to the other steel components. I do not have the specs anymore as I am no longer employed by the company but I assure you all types of metals were used throughout the unit. Cast iron was common but I also audited heavy construction vehicles where weight really did not matter.

I'm absolutely sure those rims are not cast-iron. They are most likely steel plate that has been rolled and pressed into the shape wanted - this is how all common (and nearly all of the less common) steel rims are made. Any road-going car that hasn't got Aluminium rims (or magnesium in very rare cases) have pressed steel rims.

Steel is a material that changes properties when heated - whether it is heated and cooled quickly or slowing will determine in what way it changes its properties.

It may well be fine to use those rims. But I wouldn't risk it. There are some things worth risking, and others not worth it.

Also, by the time you've cleaned them up and painted them, you have probably paid nearly half of the price of a new rim anyways.

--
Mats

I just saw a picture on MSNBC and thought of this thread:
http://www.msnbc.com/modules/interac...29067017&pg=11

The web-page will try to open a pop-up with the pictures so you'll need to enable that.

[edit]Picture 20 also looks like it might deal with melted rims.[/edit]