O1 steel for a chopper?

[stabman]

Thinking of using some O1 steel to forge a chopper.
Does anyone have experienced opinions as to the suitability of 1/4" O1 for a chopper?

 

[Charlie Mike]

Nice to see you making the leap to knife making!

 

[stabman]

Nice to see you making the leap to knife making!

I did one before.

 

[Charlie Mike]

Nice work!

 

[stabman]

Nice work!

Thanks

 

[james terrio]

Cool knife!

O1 is very good all-around steel and quite tough; it will certainly work. I've only made one sort-of chopper in O1 (3/16" stock, 9 1/2" bowie) and it holds up very well to chopping. I haven't tried to pry open any oil drums with it

5160 seems to be the go-to steel for forgers who want high toughness, it may not hold an edge as well as O1.

Personally I'd choose CPM-3V, it will beat both of those in both toughness and edge-retention, but I'm a stock-removal guy. I sure wouldn't want to try to forge 3V.

 

[Nathan the Machinist]

I noticed a few different steels used at the world cutting championship in Atlanta this year. M4 was the most popular, but there was 5160 (I think) 52100 and O1 also. So it made somebody's list.

 

[insanity]

I've used O-1 in a number of large blades, up 18". I like it.

Wayne S

 

[Todd Robbins]

Reggie Barker used O-1 in his competition cutter that won at Blade some years ago.

 

[Danbo]

While O1 wouldn't be my first choice in a chopper, it would work just fine. I would choose L6, 5160 or CPM3V over the O1, though.

 

[lazlo]

M4 was the most popular, but there was 5160 (I think) 52100 and O1 also. So it made somebody's list.

How much of that is the Indian though? I'm pretty sure Donavon can out-cut me with a butter knife

 

[stabman]

Sounds like it's a go when the steel arrives!

 

[Nathan the Machinist]

In my mind, a big difference between "chopper steel" and "not-a-chopper steel" has to do with carbon content. I think this is largely due to carbides (which tend to reduce overall toughness) and the *type* of martensite formed. Lower carbon steels form more lath martensite than the plate martensite of a higher carbon steel. All else equal, lath is tougher. I think this is part of what makes 5160 so tough. I wonder if you could achieve that with O1 by putting less carbon into solution?

My guess (and this is just speculation) is you'd probably still want to do a normal full austenitazation to get eveything spred out, but just let it cool to form fine pearlite. Then austenitize again at a lower than usual temperature (1450?), letting it soak the normal 15 min then quench. I wonder if that would form a tougher martensite?

Anybody with any experience doing this?