Stellite 6k vs any high alloy/high carbide steel

[Bodog]

I know some of the bare basics about this metal but does anyone have any practical experience with it versus any steel like m390, k390, 10V, and s90v/s110v? I see its heyday, if you can call it that, was quite awhile ago. Any reason it wasn't used more? With the current crop of high carbide steels that rust easily gaining ground is it worth a look see in a Mule blade to test its capabilities as a rust resistant super long wearing blade metal?

[Bugout Bill]

If Stellite behaves any similar to SM-100, the results will be something comparable to a titanium knife with significantly lower toughness.

[PayneTrain]

I have absolutely no experience with Stellite, but I found a pretty good explanation here from alphaknifesupply.com:

" Stellite 6K is a cobalt alloy. It is not steel. When it is made, the chromium, molybdenum and tungsten combine with carbon to form carbides. The cobalt forms a soft and strong matrix that holds the carbides in place. This means that a Rockwell or other hardness tests will test the matrix and give relatively low readings. The hardness and wear resistance are in the carbides, not the cobalt.

Stellite 6K is excellent for some uses and is a poor performer for others. For example, Stellite is excellent when used for cuting meats & vegetables. The edge holding is better than steel. However, if used for chopping hard wood, the soft cobalt rolls over and the knife does not cut well. It has extreme corrosion resistance. It will not corrode in salt water."

It's apples to oranges. Like any alloy choice, it depends what you want it to do.

[Cliff Stamp]

Any reason it wasn't used more?

It didn't make a very good knife and it was very expensive. Plus it had a lame name, Stellite 6k can't compete with CPM 154CM PM .

I have used pretty much all of the cobalt alloys and even used a forged stellite blade and even cast (dentretic ones). It is a very weak material. The only thing really it had for it was high corrosion resistance, but if you look at how properly hardened stainless steel behaves it is hard to argue there is a practical advantage.

If I had to pick one of the many I used as a work knife it would be Boye's Cobalt hunters simple because of the way he ground them they cut very well and he had solid hand ergonomics and all other aspects which make a quality knife.

[Stuart Ackerman]

What about a Serrata in Cobalt, Cliff?

[Cliff Stamp]

Is that an offer?

[Stuart Ackerman]

We both wish, methinks?
If Sal took the ball and ran with it, who knows?

( Apologies if my original statement sounded like an offer? )

[Cliff Stamp]

Any experimentation is good experimentation, however I have a fair amount of experience with Cobalt based alloys and I have not seen them competitive with steel. However it may be that we are simply using the wrong ones. The super alloys (actual materials term) is a very broad class of materials.

[Bodog]

Any reason it wasn't used more?

It didn't make a very good knife and it was very expensive. Plus it had a lame name, Stellite 6k can't compete with CPM 154CM PM .

I have used pretty much all of the cobalt alloys and even used a forged stellite blade and even cast (dentretic ones). It is a very weak material. The only thing really it had for it was high corrosion resistance, but if you look at how properly hardened stainless steel behaves it is hard to argue there is a practical advantage.

If I had to pick one of the many I used as a work knife it would be Boye's Cobalt hunters simple because of the way he ground them they cut very well and he had solid hand ergonomics and all other aspects which make a quality knife.

Are you referring to stellite 6k or 6b?

[Cliff Stamp]

Are you referring to stellite 6k or 6b?

I have used both. I have used pretty much all cobalt super alloys used in cutlery, including some very rare ones such as forged knife which may be one of a kind and even the trade versions such as Talonite.

Here are three :



The top one was forged from Stellite 6BH, the bottom is Stellite 6k, the middle one is Boye's cobalt.

[Bodog]

And all were pretty much crap?

[tvenuto]

And all were pretty much crap?

From reading his posts a better way to say it would likely be that all had advantages that were not worth the tradeoffs and expense.

[Cliff Stamp]

Essentially, they all are fairly weak and thus you get deformation much easier. Roman Landes was the first person to actually show in a micro-graph what these alloys look like and the carbide structure is massive. Now for some applications this is useful because you get very different wear depending on the relationship of the size of the carbides in the steel vs the size of the abrasive. What you don't want, in gross wear, is to have carbide which are much smaller than the abrasive as the abrasive won't really see them at all. But if the abrasive is much smaller, it can wear around the carbides and they can just come out.

I have a lot of respect for guys trying new things, and figuring out how to forge that into a knife deserves credit but if you ignore the novelty, it is hard to see why you would practically want it for a knife.