Why would 17-4 stainless steel lose its magnetic properties after being melted? Any ideas? How could they be gotten back?

12/3/2010 10:08:14 PM

Im a little rusty on my Material science so hopefully someone can add to this. I think that once you reach the curie temp the molecules rearrange so that the magnetic poles dont align and cancel each other out. You could try cold working which MIGHT get the surface realigned, the magnetic field wouldnt be as strong as before and to much would make it brittle.

12/3/2010 11:25:26 PM

^Thats just silly. Magic, of course.

12/5/2010 2:24:03 PM

17-4, 18-4, etc. are austenitic stainless steels. Overall molecular structure is FCC (face-centered cubic), and ^^ is right on about Curie temperature, which just so happens to occur at about the point of austenitic formation. So you get transformation from BCC to FCC and transition from magnetic to nonmagnetic. With proper cooling rate, you get a solid solution that remains austenitic.

400 series are mostly martensitic and magnetic.

12/6/2010 1:28:37 AM

Do you think the cooling rate needs to be rapid or slow and controlled?

12/6/2010 11:34:24 AM