A cluster of knives. Which is which?

[Fred.Rowe]

As I was grinding this set of four hunters, I lost track of the one that was forged from 52100 steel. The other three had been forged from W2 round stock, but one of them had been forged from a 2 3/4 inch roller bearing.
I had marked the tang of the odd one, with a Sharpie; not too sharp, on my part. it washed off as I was grinding.
It did not take long to discover which one it was, as rust tended to form on three of the blades, when dipped in water, but not the fourth. That chromium at work in the 52100.
The heat treat on all four blades was the same, except for the higher hardening temperature for the 52100.

• 
  forge
  normalize
  spherodize anneal
  grind
  normalize three times in succession.
  harden
  temper, two, 2 hour cycles at 450fh

The photos were taken right after the acid etch had been neutralized and the blades wiped off.
Can you tell which blade, is the 52100?

Fred

 

[adammichael]

the far right?

 

[Fred.Rowe]

the far right?

A good eye:thumbup:. It is really obvious now that I have them rubbed out. Looking along the hamon on the 52100 blade, you can see the carbides "dancing along the transition line. The surface of the 52100 is slicker also.
I like both steels for different reasons.
I normally do not get this much definition in 52100. I think it must have something to do with the three normalizing cycles just before the hardening is done. I don't get any warpage as quenched since I started doing the triple cycles, even on long thin blades.:thumbup:

Fred

 

[Keith_H]

but 3 are W1 and one looks different so... those are nice.