Maraging C300 Heat Treat 1

[legrand01]

I have a question regarding Maraging C300 (Vasco C300, etc.).
We have been heat treating this in-house for years and years and the pieces look terrible. They can develop scale sometimes, and just generally look bad, sometimes leading to scrap and other times needing to be "polished" or cleaned up.

In an attempt to have the parts "done" after heat treat (since we don't want to machine the hardened material), we sent some parts out to be vacuum heat treated with the assumption that they would look "better", that they wouldn't oxidize, etc. Unfortunately they look pretty much the same.

I've attached a picture of one of the parts. Can anyone tell me if this is normal under vacuum heat treating conditions or not? Thank you.

 

[legrand01]

Image that didn't attach?

 

[metengr]

You might find this article very useful for Ni maraging steels;

http://www.nickelinstitute.org/~/Me...MaragingSteel_EngineeringProperties_4419_.pdf

 

[legrand01]

Thank you. Very informative indeed. Question though, how do I call out the proper heat treatment on a drawing or on a PO, etc.?

 

[metengr]

legrand01;
There are several options that range from referencing known material specifications that fit your need or developing your own custom specification. In my line of work we typically refer to internationally recognized material specifications on the PO or contract because minimum requirements are provided and you can always provide additional requirements to those listed.

In your case, you need to determine if perhaps an aerospace standard, as mentioned in the attached article, would work and could be referenced on the PO or contract.