High Expansion Coefficient Steels

[will123]

I am in the UK and would like to find a source of steel with a expansion coefficient in the region of 20?m/m.°C, preferably in plate form (although larger section bar, which could be forged flat could be acceptable).At the moment we are using austenitic stainless, but ideally need to increase the expansion.
Our primary supplier of metal cannot get hold of AMS 5623 and the lead time on Aubert & Duval's GD223 is too long.
I would appreciate any advice on alternative steels with expansion coefficients around this value or possible suppliers I could try.
Thank you in advance.

 

[mcguire]

The maximum for austenitic stainless steel is 19m/m/C at nickel equivalent of 13% and chromium equivalent of 17%. The closest commercial alloy to this is 305. The rate drops off quickly as the alloy becomes leaner in nickel equivalent.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[israelkk]

will123 and mcguire

It is really annoying that you both use "m" once for Micro meter and once for meter. Why not write 0.000020 m/m?

 

[will123]

Israelkk,

Apologies for causing your annoyance - I cut and pasted my message from Word and unfortunately I did not spot that the Mu did not reproduce correctly.

 

[EdStainless]

Some of the 200 series alloys also have high CTE, like 201. This might give you more options.

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[will123]

Thank you for the responses - I should have added in the original message that the service temperature of interest is in the region of 20-150°C. In this range, according to my reference 201 has a coefficient of expansion of 0.0000157m/m.°C and 305, 304, 302 etc are at 0.0000173m/m.°C.
The 300 series alloys is the fall back option at the moment, should I fail to secure a source of steel with higher expansion than these.

I appreciate the likely higher cost, but this is for a motorsport application and performance in service is of primary importance.

 

[rorschach]

Must it be steel? What about Aluminum?

 

[EdStainless]

What about strength and corrosion resistance?
There are many common brass grades with values that are about 20.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[will123]

Again thank you for your replies.
The application is as a stiffening plate fixed to aluminium components. Therefore I wish to maximise the modulus, which rules out aluminium. I did consider brass, but again the reduced modulus is a factor.
The part is stiffness rather than strength limited and therefore strength of the material is not a major concern. Also corrision resistance is not a priority- it can be painted!