Vanadis 10 SuperClean

[Gerhard Gerber]

I have almost a meter square of this stuff 4.2mm thick plate, a gift, with a chuckle and "it is sh1t to grind" from my mentor 

The data sheet is very specific, at a guess the blade would be in the kiln for at least 45 minutes, and "the tool should be protected against decarburization and oxidation during hardening"

Plate/air quench.

Let's assume I'm not trying to HT this steel to the optimum, just trying to utilize this steel within the limitations of my equipment.  

How much performance would I loose if I soaked the blade without foil? Could that destroy the steel?

Rene' is a master on the grinder, my equipment is no better that his, and he has better belts, so if he gave up on the steel I don't intent to waste my time......

I was thinking a few cleavers with minimal grinding, sub-par HT on a very tough steel might still make a good tool?

 

[Doug Lester]

Just looking at the specs for the steel it has a crazy high carbon content.  It's also a high allow steel with a lot of manganese, molybdenum, chromium, and vanadium.  It's designed for high abrasion resistance (as in the best knife you'll never be able to resharpen).  It will also be a mother bear to grind.  You're going to need a regulated high temperature oven to heat treat it in.  No heat treating instructions were given but I would guess that it would be at a high temperature for a long  period and rely on the vanadium to pin the grain size.  It is also not a high strength steel so it could have a problem with edge chipping.  Not a very good choice for a chopper of any kind.

There's a reason that your friend Rene' gave up on the steel.  Some steels, even when they're free, aren't worth the cost.

Doug

[Gerhard Gerber]

2 hours ago, Doug Lester said:

 (as in the best knife you'll never be able to resharpen). 

I got all his leftover D6 as well....same story 

Quote

Uddeholm Vanadis 10 SuperClean is a high vanadium alloyed powder
metallurgy tool steel offering a unique combination of an excellent abrasive
wear resistance in combination with a good chipping resistance. It is
manufactured according to the powder metallurgy process giving a very
low amount of non-metallic inclusions.
In tool making Uddeholm Vanadis 10 SuperClean offers a good
machinability and grindability together with a good dimensional stability
during heat treatment. It can normally be hardened to 60–65 HRC.

 

[Doug Lester]

On the listing that I found on-line it said wear resistance 100% and chip resistance 25%, whatever that means.  Maybe one of the real metallurgists will chime in here.

Doug

[Alan Longmire]

https://www.alphaknifesupply.com/Pictures/Info/Steel/Vanadis6-DS.pdf

https://www.uddeholm.com/app/uploads/sites/54/2018/05/Tech-Uddeholm-Vanadis-10-EN.pdf

Looks like it is the least grindable steel Uddeholm-Bohler makes...   definitely not impact-rated, more for a continuous cut in abrasive materials.  I think it says something that in the brochures on the Vanadis series the dies are V10 but the punches are V6.  That says it is quite wear resistant, but not tough enough to act as an impactor.  

With 2.6 % C I doubt decarb will be a huge problem.  You could lose half the carbon and still have a heck of a steel.  Might even make it tougher!  

[Jerrod Miller]

10 hours ago, Gerhard Gerber said:

I have almost a meter square of this stuff 4.2mm thick plate, a gift

I'd say this is evidence that "mentor" definitely does not equate to "friend".  I'd say play with HT and see what you can get.  You certainly don't have anything to lose as far as the metal is concerned.  If some one gave that to me, it would find a nice home at the bottom of my steel pile, protecting the concrete floor from the good steel I drop on it.  My time is too short to play with something so difficult.  

[Geoff Keyes]

Maybe you could face a file guide in it.

Geoff

[Brian Dougherty]

Trade it to someone who needs to make a dozer or excavator edge repair for something more useful to you?

[Gerhard Gerber]

15 hours ago, Doug Lester said:

On the listing that I found on-line it said wear resistance 100% and chip resistance 25%, whatever that means.  Maybe one of the real metallurgists will chime in here.

Doug

I get what you're saying, I think marketing wrote that bit I quoted 

13 hours ago, Alan Longmire said:

With 2.6 % C I doubt decarb will be a huge problem.  You could lose half the carbon and still have a heck of a steel.  Might even make it tougher!  

Now THAT'S what I wanted to hear!  Now we need to find out if it's a case of great minds thinking alike or fools never differing 

In all seriousness, this is exactly what I was thinking, you expressed it better.

13 hours ago, Jerrod Miller said:

I'd say this is evidence that "mentor" definitely does not equate to "friend".  I'd say play with HT and see what you can get.  You certainly don't have anything to lose as far as the metal is concerned.  If some one gave that to me, it would find a nice home at the bottom of my steel pile, protecting the concrete floor from the good steel I drop on it.  My time is too short to play with something so difficult.  

He's Swiss, not sure about their version of sarcasm  He actually used a thicker sheet of the stuff to make a new work surface for his band saw.

My blacksmith neighbour and occasional collaborator often leads me down the rabbit hole of forging steel into the required shape for a certain project.  The three cleavers I made this year were the first, complete and utter waste of time to get a little extra width out of a piece of leaf spring.

Next one was my idea, trying of get wide enough material from a large bearing race to make a large kitchen knife........called a halt to that after the first forging session.

12 hours ago, Geoff Keyes said:

Maybe you could face a file guide in it.

Geoff

Excellent idea.

[Charles dP]

I wonder if it could make a descent platen-face.

[Gerhard Gerber]

1 hour ago, Charles du Preez said:

I wonder if it could make a descent platen-face.

I considered that as well, but it's very thin, so mounting it or fixing mounts to it might be an issue.

I'm sure I can heat treat the 5160 platen I'm having milled out, while this stuff.....who knows.

I need to heat treat a 14C28N blade soon so I'll make a test blade from this stuff.......seeing as how I have to go past 1000C I try to do more while the kiln is hot.

[Gerhard Gerber]

Serbian cleavers are still in fashion, and uncomfortable as I believe they will be in use I have at least 4 potential client gagging for one.....

The Vanadis is the only steel I have to make a blade that wide, so instead of test blades I made a cleaver as wide and I can fit in my kiln

 

Rough grind was more than an hour, best part of two 36-grit belts shot, but I was happy with the result none the less.

I thought I was working it through the grits on the grinder, but realized while hand sanding 220 grit that a) hand sanding this stuff is senseless and b) lots of those lower grit scratches were still in there, largely untouched by some of the belts.

Decided this blade will have a low-grit "satin", no other way.

 

So spoiler, things happened suddenly one Friday evening and I took the opportunity to get this blade done, and I did not take the time to ask and make sure.

I followed the recipe, saw Quenching Media - forced air/gas so in my mind that equated to put it between the plates and blow air in there.

Problem came when I wanted to check the tempering required.  I did put the blade in with the others for my normal tempering cycle.

 

Can somebody please translate this for me?

What is martempering?  was I supposed to quench the blade in oil at 500C, or was the first temper cycle supposed to be in oil at 500C?

 

HARDENING

Pre-heating temperature: 600–700°C (1110– 1290°F)

Austenitizing temperature: 1020–1100°C (1870– 2010°F)

Holding time: 30 minutes.

Note: Holding time = time at hardening temperature after the tool is fully heated through. A holding time of less than 30 minutes will result in loss of hardness. The tool should be protected against decarburization and oxidation during hardening.

QUENCHING MEDIA

• Forced air/gas

• Vacuum furnace (gas overpressure 2–5 bar)

• Martempering bath or fluidized bed at 500– 550°C (930–1020°F)

• Martempering bath or fluidized bed at 200– 350°C (390–660°F) whereby 350°C (660°F) is preferred.

Note 1: Temper the tool as soon as its temperature reaches 50–70°C (120–160°F). Note 2: In order to obtain the optimum properties for the tool, the cooling rate should be as fast as is concomitant with acceptable distortion

 

 

[Jerrod Miller]

The purpose of martempering is to rapidly cool the material rapidly to beat the nose of the TTT curve (page 6 here) without actually forming martensite yet.  This reduces un-needed stresses and distortions due to the phase change happening along with thermal contraction.  I am not entirely sure why they are calling out the 2 different ranges for martempering, other than that the hotter one is probably to make it easy to not get bainite, while the second one is easier to get bainite.  Notice that in the TTT it looks like you have over five minutes to cool below the nose of the curve, but watch out for bainite formation!  Then look at the CCT (also on page 6) which indicates that you definitely want to go a bit faster to avoid carbide formation.  Hence why you would want to martemper at all versus just air cool.  Looking at that data, you definitely want to go from about 1050C to 500C in about 5 seconds, then hold there long enough to even out the temperature completely (a few seconds is certainly adequate in blade geometries).  From there you want to cool fairly rapidly to about 70C then temper.  I would think the optimal process for this would be to use a salt bath (or similar) to quench from 1050C to 500C, wait a few seconds then quench in 60-70C oil.  After a few seconds in the hot oil move straight to temper.  

 

At least that is what I would do if I had to use that material.  I would never willingly use that material, because all that is a pain in the rear.  

[Gerhard Gerber]

Hi Jerrod

 

Thank you for that English to English translation 

 

I told the guys waiting that if I get the heat treat right the finish will be a bit rough, maybe not pretty but hopefully practical......and that sounds like an excuse even to me.

Most likely my last attempt with this steel.

 

I want to finish this knife anyway, just feel I need to test it to make sure its not brittle.

 

[Doug Lester]

I did martempering once with 52100.  I quenched in hot oil, not a good idea because it might have been too hot to transfer heat from the blade fast enough and it's not a bad way to burn down the shed.  I would try Jerrod's suggestion of a low temperature salt bath.  From the TTT curve I estimated that I had a 50/50 mixture of martensite and bainite (pointed out to me later that it's not a great idea)  The blade groaned and popped as I tried to bend it to 90° and was pretty close before it broke.  An identical blade, at least as near as I could forge and grind it, was hardened in [i]warm[/i] oil and I couldn't bend it even with attaching a pipe over the handle.  I had to get my 4 lb hammer and beat on it to get it to break.  Lesson:  A mixture of martensite and bainite doesn't do much for a knife blade.

 

Doug

[Gerhard Gerber]

Arise necro thread!

I couldn't get decent finish on this blade to save my life, so I resorted to the angle grinder with a flap disk and gave it a weak flint-knapped finish.

Slapped a Kiaat handle on it and did some silly-bugger tests to check durability.
A friend of mine extended his business and opened a butchery and bottle store, so I took the cleaver to Olavi the butcher for some real world testing.  The manager sent me some video of them taking apart a sheep carcass, quite impressive.  After the testing was done I couldn't get it over my heart to take his toys away, so I donated the cleaver

 

I dropped by to restock about a week ago, saw Olavi busy in the butchery and asked to see the cleaver.  There was a tiny piece of raw meat stuck to the front of the handle, so no doubt it still sees regular use.
It's still very sharp, few small chips and edge damage, but all things considered I was amazed.
You couldn't wipe the smile off Olavi's face with a baseball bat.

I cut 4 blanks a while ago that will be turned into high performance meat processors some or other year, they won't be pretty, but they will be expensive.