AEB-L patina

[RokJok]

Up front disclaimer: This is *NOT* a problem and I ain't whining about it.

A WD5 arrived with some dark patina like staining on the logo side of the blade. It's a kitchen user, so no objection to its presence since the patina doesn't affect performance. It's spread a bit through daily use of the knife since then, from acidic ingredients like onions & lemons I suppose. I was surprised at it, though, because AEB-L is well established as a tough & effective stainless steel.

So my question is: Has anybody else seen this phenomenon? Or am I one of the Chosen ones?

In the attached photo its initial location was toward the front of the blade mostly on the flat above the bevel grind, with just a bit trailing down onto that bevel. The larger dark patch toward the heel of the edge is just a stonewashed reflection of me taking the picture.

My review of my first stint using the WD5 (spoiler: lovin' it!!), including why its finger guard is shorter, is at https://www.bladeforums.com/threads/fixed-blades.1829548/post-22378242

 

[TheGrownUpKid]

.......Shoulda called it WD40......

 

[Cobalt]

I don't have any aeb l, so I have no idea how it behaves. I wonder how it responds to vinegar.

 

[MacLaren1]

I wonder if Busse would consider using Nitro-V for their thinner stock blades as well?

 

[Cobalt]

So, I just looked up the chrome content of AEB-l. 12.8%. That is near the edge of what is considered stainless steel and in between D2 and ATS34, both of which will surface rust fairly quickly in my experience. Especially if the finish is not a high polish or fine satin, both of which resist rust better. So your experience makes sense. As a kitchen user, it will get some caustic liquids on it.

 

[ironwagon]

I used mine for about 15-20 minutes prepping tomatoes, onions, lettuce, and an avocado and it's still looking pretty clean.

View attachment 2441939

 

[Cobalt]

I guess Rokjok has a special one

 

[Jerry Busse]

Rokjok,

Try wiping the blade down with some acetone. It appears to have a slight layer of the paste left behind from the tumbling process.

Thanks!

Jerry

.

 

[RokJok]

Thanks Boss Hog!!
After the acetone bath The Shadow remains. As noted, no functional impact, simply cosmetic.

And speaking of cosmetics, do you have any tips on what I should have said to the teenage girls giving the side eye to the old guy in the nail polish aisle fondling bottles of acetone nail polish remover?

Many thanks to that dastardly Dan dude for a knife that's seeing daily duty in the kitchen and hasn't lost a lick of slicification since day one. But we've come to expect that level of performance from y'all and you just keep delivering.

 

[ferider]

And speaking of cosmetics, do you have any tips on what I should have said to the teenage girls giving the side eye to the old guy in the nail polish aisle fondling bottles of acetone nail polish remover?

You don’t buy it … you steal it from wife or daughters … same goes for nail polish when you’re out of loktite.

 

[willmtn1]

Thanks Boss Hog!!
After the acetone bath The Shadow remains. As noted, no functional impact, simply cosmetic.

And speaking of cosmetics, do you have any tips on what I should have said to the teenage girls giving the side eye to the old guy in the nail polish aisle fondling bottles of acetone nail polish remover?

Many thanks to that dastardly Dan dude for a knife that's seeing daily duty in the kitchen and hasn't lost a lick of slicification since day one. But we've come to expect that level of performance from y'all and you just keep delivering.

Have you tried going to the paint thinner aisle and buying a man jug of pure acetone? Not all acetone is created equal and some brands aren't pure and will leave behind a residue.

 

[Cobalt]

Have you tried going to the paint thinner aisle and buying a man jug of pure acetone? Not all acetone is created equal and some brands aren't pure and will leave behind a residue.

 

[Kraken82]

Up front disclaimer: This is *NOT* a problem and I ain't whining about it.

A WD5 arrived with some dark patina like staining on the logo side of the blade. It's a kitchen user, so no objection to its presence since the patina doesn't affect performance. It's spread a bit through daily use of the knife since then, from acidic ingredients like onions & lemons I suppose. I was surprised at it, though, because AEB-L is well established as a tough & effective stainless steel.

So my question is: Has anybody else seen this phenomenon? Or am I one of the Chosen ones?

In the attached photo its initial location was toward the front of the blade mostly on the flat above the bevel grind, with just a bit trailing down onto that bevel. The larger dark patch toward the heel of the edge is just a stonewashed reflection of me taking the picture.

My review of my first stint using the WD5 (spoiler: lovin' it!!), including why its finger guard is shorter, is at https://www.bladeforums.com/threads/fixed-blades.1829548/post-22378242

My guess is it's the heat tint that forms on the surface after cryogenic heat treatment it's a light brownish colour forms on the surface but comes off when you surface prep & once media blasted however if the media blasting is rushed and not done properly and evenly patches of the brownish heat tint can remain and not noticed straight away as fine media dust on the surface will hide it. Only becomes evident once some WD40 is applied or as time progresses it can get a bit darker it's nothing to worry about though.

 

[Jerry Busse]

Rok Jok,

Please return your blade and we'll take it for another tumble!

Thanks,

Jerry

.

 

[RokJok]

Deeply appreciate the offer, Boss. PM sent. Sorry it's long. I'm one of those who write as if they're paid by the word.

 

[Gravelface]

I love my kitchen duty knives, almost feels like sending them on vacation compared to the normal crap they endure.

This SR-7 is straight on patina, no “classic rust”, she’s much darker in person. Been on full kitchen detail since Blade 07ish I think. She’s a beauty.


This after a full on descaling, knocking off the lumpy rust. I forgot what steel this was.

 

[Cobalt]

I love my kitchen duty knives, almost feels like sending them on vacation compared to the normal crap they endure.

This SR-7 is straight on patina, no “classic rust”, she’s much darker in person. Been on full kitchen detail since Blade 07ish I think. She’s a beauty.
View attachment 2453193

This after a full on descaling, knocking off the lumpy rust. I forgot what steel this was.
View attachment 2453180

That's not patina, that's dirt!!!

 

[Cobalt]

Is patina character? Maybe. I just picked up a bronze case watch and within a week parts of it turned green and the rest darkened. That's part of it's appeal. With knives, it depends on the type of knife.

Is this patina?

Maybe

Is this just dirty? Patina? or both?

maybe.

 

[Laurarium]

Nah, she just tanned a bit

 

[Laurarium]

So, I just looked up the chrome content of AEB-l. 12.8%. That is near the edge of what is considered stainless steel and in between D2 and ATS34, both of which will surface rust fairly quickly in my experience. Especially if the finish is not a high polish or fine satin, both of which resist rust better. So your experience makes sense. As a kitchen user, it will get some caustic liquids on it.

Differernce is AEB-L is much less prone to froming pit rust due to low carbide volume, and due to more free Chromium in the actual steel instead of being in the carbide, AEB-L is more corrosion and stain resistance than both of D2 and ATS34.
For higher corrosion resistance, consider 14C28N LC200N Magnacut