Cost & Feasibility of Metallurgical Analysis

[rxmelaun]

I'm a layperson who is in need of some basic information; is it possible to determine what steel has been used in the manufacture of an OEM crankshaft? If so, any idea as to what that would cost?

Thanks in advance and sorry if it's a silly question.

 

[kenvlach]

First use the Internet to find or at least narrow down the potential alloys used. I.e., by vehicle, engine, performance options. Maybe only cast nodular iron for stock engine; forged steel for high performance.
One source mentions
"5140, 4130, and 4340 steel"

http://www.popularhotrodding.com/tech/0710phr_crankshaft_tech/index.html

So, narrow done the possibilities. If more than one, then only need to test for a few specific alloying characteristics.

 

[rxmelaun]

I'm aware of the various basic alloys; the problem is it is an OEM Honda motorcycle crankshaft and there appears to be a total dearth of information about what they use.

I know that everything from nodular iron to E4340 is used; how can I determine what has been used in such an OEM item when the manufacturer won't say?

 

[metengr]

rxmelaun;
If you have a spare or the original crankshaft that is out of the engine, you can have the material typed at a Metallurgical Lab for under $200.

 

[rxmelaun]

Brilliant; thanks.

Rich

 

[DaveScott]

rxmelaun, there is another, older, method which I came across once: If you could get some samples of known crankshaft material and use a high speed grinder, then you could compare the sparks from the known types to the unknown type. Perhaps if you got someone to photograph the results it might help as well.

See the following links for further info:

http://www.ohiosteel.org/homepage/Spark Testing for Mystery Metals.pdf

metalworking.com/Dropbox/NAVY-repairmans-manual-Chapter03.pdf

 

[rxmelaun]

Dave - thanks for that. amazingly, I found the same document last night after some subsequent searching.

What degree of accuracy can this laboratory typing achieve? For example, can it distinguish between say 1045 and 4340? Or is it more general than that? Thanks again.

 

[CoryPad]

A true metallurgical evaluation will tell you the exact alloy, the production method (casting, forging, cut grooves, rolled fillets, whatever), presence of surface hardening, etc. Of course, this evaluation is destructive. If you need non-destructive, then you are more limited. There are techniques that can give you an idea of the composition, but it may not be able to differentiate low alloy steels.

I wouldn't bother with the spark evaluation. That is more for sorting. What would you do with the incredibly basic information it provides?

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[rxmelaun]

I am trying to determine if the crankshaft can be case hardened, or induction hardened, and/or shot peened; the shop needs to know the material so it knows what process(es) it can apply - if any. I want to know if it is worth pursuing as a crankshaft in a racing engine.

Or is it a nice doorstop?

 

[tripleZ]

An EDS scan of a few areas of the shaft will give you the approximate elemental composition of elements above an atomic # of 12. You can get the percentages below 12, but they're a little spottier due to surface oxides and whatnot. Probably an EDS scan and a couple pecs of material for carbon analysis will give you the ballpark range of elements, which can be compared to the standards.

That's been our procedure in the past for identifying foreign metallic material (customers sometimes like to jump to conclusions that every problem is our fault), and so far it's relatively accurate. It'll probably cost in teh $200 range for something that basic.

 

[rxmelaun]

So what lab are you with? Or should I try to find a local lab?

 

[NickE]

My favoirite lab is Steel Testing Laboratory here in Detroit. But they can only do hardness and 16 element chemistry, usually really low alloy low carbon steels.

A much more comprehensive evaluation can be done by IMR Test labs...

IMR Metallurgical Services
4120 Bishop Lane
Louisville KY 40218
PH: 502-810-9007
FX: 502-810-0380
imr(at)imrlouisville.com

One note:
Metallurgical Laboratories do exactly what you ask them, nothing more, nothing less. You must know the right questions to ask to get the answers you want.


Nick
I love materials science!

 

[rxmelaun]

Nick,

Thanks;I'm going to contact the guys in Louisville.

Richard

 

[tripleZ]

We use Metallurgical Associates Inc. in Milwaukee. If you're anywhere near a group of automotive/motorcycle/transmisson parts manufacturers, there will inevitably be a met lab nearby somewhere. They get all kinds of goofy things to analyze. Last time I was over there, it was a slew of engine components from Harley and some transmission components from OshKosh (trucks).

 

[rxmelaun]

Thanks - the guys in Louisville apparently also have automotive experience. I believe that several manufacturers have factories there. I know that the Corvette plant is in Bowling Green and I think that Honda also has a plant in the state.