Formable substitute for Maraging 350 1

[space1space]

I am looking for a material which is weldable and formable (spinning or deep draw) which is available in thin sheet (.025 to .031 inch) which is similar to maraging 350 in UTS. Any ideas out there? (also a source would be helpful)

 

[TVP]

As far as I know, this is an impossible request to fulfill. Maraging steels essentially have the highest strength of commercially available alloys, especially if you limit the product form to be sheet materials. Carbon and alloy steels with high carbon content (spring steels) can be obtained in strip, but the maximum strength levels at thicknesses of ~ 0.6-0.9 mm are only ~ 1800 MPa (< 270 ksi). PH stainless steels (17-4, etc.) and high strain hardening austenitics like Type 301 are also limited to less than 280 ksi tensile strength.

Perhaps you can provide a little more background on the reasoning for this. Is this an existing application? Is a 350 maraging steel already being used? Why is a change necessary?

 

[space1space]

No, this is not an existing application. We are doing a weight reduction program on a proposed design. We wish to go as high as possible in UTS without encountering problems such as stress cracking. D6AC was a former candidate but does not appear to be totally suitable. The application is in a small ablatively cooled combustion chamber, so thermal problems will not be evident.

 

[TVP]

Why is maraging steel not acceptable? When you say &quot;stress cracking&quot;, do you mean stress corrosion cracking?

 

[RPstress]

You could try AerMet 310 from Carpenter (

http://www.cartech.com).

That'll get you above 310 ksi. Not sure how formable it is when annealed, and it won't be all that wonderful for SCC, though it should be better than Maraging 280, etc.

Depending on the shape, it might be worth contacting SPS (

http://www.spstech.com)

about using one of their multi-phase alloys. Those can be work hardened before aging to get properties approaching 300 ksi. They're very stainless and don't appear to get into trouble due to SCC or crevice corrosion. If it's a simple shape, it might just be possible that the forming op would put in enough cold work to approach the properties you want. However, these materials are aimed more at bar and forgings.

-RJP.