N690 Magnetism after heat threatment

[Peter Medveď]

Hi all, my blade from N690 material is after heat threatment - quenching no more magnetic.
Is this normal?

 

[rpttrsn]

I think your question needs to be re-written.

 

[Peter Medveď]

I think your question needs to be re-written.

how an why?

 

[rpttrsn]

Hi all, my blade from N690 material is after heat threatment - quenching no more magnetic.
Is this normal?
Do you mean:
After heating blade (N690) and quenching, it was no longer magnetic. Is this normal?

If this is what you are saying you might want it posted in the
"General Knife Maker's Discussion" of the forum.

Just trying to help you to get a answer from those who make knives.

 

[Larrin]

It means you have a lot of retained austenite. Usually from austenitizing too high.

 

[Busto]

The added Chromium and Nickle Make N690 Theoretically Non-Magnetic.

 

[Larrin]

The added Chromium and Nickle Make N690 Theoretically Non-Magnetic.

No, it doesn’t.

 

[neo71665]

The added Chromium and Nickle Make N690 Theoretically Non-Magnetic.

Um nickel is magnetic

 

[Willie71]

The added Chromium and Nickle Make N690 Theoretically Non-Magnetic.

you would need 300 series stainless levels of nickel to lower the austentizing point to room temp. N690 is a martensitic stainless.

 

[Busto]

No, it doesn’t.

Did you Miss the Theoretically part of the Non-Magnetic...Ferritic Stainless has more Iron where less Iron is found in Austinitic SS like the 300 Series of Stainless, but there are Many Austinitic Stainless Steels. So it's not just a matter of Austinizing at a High Temperature.

 

[Busto]

you would need 300 series stainless levels of nickel to lower the austentizing point to room temp. N690 is a martensitic stainless.

So let see if I got this Right...Austinizing at a High Temperature as Larrin suggests you change the N690 to Austinitic Stainless in the Range of 300 series which by most accounts is "Non Magnetic".

 

[Larrin]

Did you Miss the Theoretically part of the Non-Magnetic...Ferritic Stainless has more Iron where less Iron is found in Austinitic SS like the 300 Series of Stainless, but there are Many Austinitic Stainless Steels. So it's not just a matter of Austinizing at a High Temperature.

Please, keep digging your hole deeper. Would you change your mind if I told you that N690 doesn’t have a nickel addition?

 

[Willie71]

So let see if I got this Right...Austinizing at a High Temperature as Larrin suggests you change the N690 to Austinitic Stainless in the Range of 300 series which by most accounts is "Non Magnetic".

Nickel stabilizes austenite, and lowers austenitizing temp. With over 10% nickel, 300 series is Austenitic at room temp.

 

[john april]

hmmm, my nickel bar stock for guards will not stick to a magnet.

Um nickel is magnetic

 

[Larrin]

hmmm, my nickel bar stock for guards will not stick to a magnet.

Nickel, cobalt, and iron are magnetic. What you have isn’t nickel. Nickel-silver maybe?

 

[Busto]

N690 doesn’t have a nickel addition?

Yes N690 is Carbon/Cobalt based with NO Nickle...Please forgive me for Questioning your Knowledge. I'll know better next time to leave Steel discussions to the Scholars.

 

[shqxk]

I really interest in whatis the percentage of RA that will make martensitic stainless non magnetic?

 

[Stacy E. Apelt - Bladesmith]

hmmm, my nickel bar stock for guards will not stick to a magnet.

Nickel silver has no silver in it, and not much nickel. It is a white brass alloy of copper and zinc with 10% to 25% nickel. It isn't magnetic.

 

[Larrin]

I really interest in whatis the percentage of RA that will make martensitic stainless non magnetic?

It's not an on-off thing, the more retained austenite the less magnetic it is.