carpenter PD1 steel - how corrosion resistant?

[harkamus]

Heya, folks. I'm in the sweaty genital sack of the United States (Georgia). It's humid and hot for most of the year. That said, I've commissioned a custom folding knife. I originally intended to have the blade made of m390. However, my maker said he's out of that steel and has given me the option of having it made out of PD1, which is supposed to be similar to 3v. I think for a folder, this kind of steel is a bit over kill. My real concern is how easily the blade steel can get corroded. The knife will be a folding flipper, so will get played with plenty. Does anyone have experience with PD1 that lives in a similar climate that's hot and humid? I would be carrying IWB. I'm also busy enough in my day to day that I don't wish to have to wipe the knife down constantly everytime I play with it or use it to cut something. I'm considering holding out for the m390, but just wanted a second opinion on the PD1.

Steel info: http://www.cartech.com/toolsteelspowder.aspx?id=2622
http://sb-specialty-metals.com/grades/pd1

Duane Dwyer of Strider is apparently a very big fan of PD1. Not that is of any concern to me. Just worthy of mentioning that since I see very few knives made of PD1.

 

[bpeezer]

I think it's technically a "tool steel", so not as corrosion resistant as a stainless. My phone app says it's similar to D2 but with better toughness and wear resistance.

 

[harkamus]

Yea I know it's a powdered tool steel. Just wanted to get a gauge for how easily/badly this stuff corrodes.

 

[Obsessed with Edges]

Carbon content slightly higher than 1095, at ~1.1%

Chromium at 7.75% (1095 has none at all), so at least some of that might contribute some corrosion resistance. Needs ~12% or more to be true 'stainless'; compare with D2 at ~10.5% chromium.

Also 1.6% Molybdenum, which is also said to improve corrosion resistance (primarily adds to toughness, otherwise).

Between the moderate carbon content and decent chromium, I'd think it should be at least somewhat more corrosion-resistant than 1095. BUT, it's still not 'stainless', so there's still no guarantee. Especially around humid/saltwater conditions (all bets are off). Corrosion-resistance drops fast when carbon content gets very high (maybe above 1.5-2%) and additional chromium isn't added to compensate. D2 is a good example of this balance, with 1.55% carbon. Without the extra chromium to near-stainless level, D2 would likely rust like crazy.

Edit: The complete lack of mention in the linked references, regarding corrosion-resistance of this steel, might be a strong hint that it's not a priority or an attribute of this steel. If it were significant, I'd think they'd probably brag about it in their documentation.


David

 

[harkamus]

Edit: The complete lack of mention in the linked references, regarding corrosion-resistance of this steel, might be a strong hint that it's not a priority or an attribute of this steel. If it were significant, I'd think they'd probably brag about it in their documentation.


David

Yea, I was afraid of this too. I will skip the PD1 and go and wait for m390. Where the PD1 excells at (toughness and impact resistance) is something I wouldn't encounter in my day to day anyway.

 

[Obsessed with Edges]

Yea, I was afraid of this too. I will skip the PD1 and go and wait for m390. Wear the PD1 excells at (toughness and impact resistance) is something I wouldn't encounter in my day to day anyway.

Wow. Just looked up the specs on m390. 20% chromium should definitely improve your odds. Waiting for that might be a good idea.


David

 

[mtangent]

Some people think the Vanadium lends some stainless ability. I have 1 3V blade, & I'm inclined to agree.
Your environment seems extreme, however, & I would wait for something better tested for stainlessness.