52100 Problems

The testing of the Bohler 52100 showed lower toughness when quenched from 1450’ and 1475’ even though they both were lower in hardness. Quenched from 1500’ and 1525’ at a higher hardness also showed greater toughness.

We found something similar with 5160. I’m finding that most low alloy steels do well when quenched from 1525’, the exception is O1 and O2.

Hoss

I’ve got more 52100 to try 1500f and 1525f for charpy samples. I used 1475f as that’s what worked for me with Aldo’s steel in the past, even though the steel for the samples was donated by Chuck.
 
The testing of the Bohler 52100 showed lower toughness when quenched from 1450’ and 1475’ even though they both were lower in hardness. Quenched from 1500’ and 1525’ at a higher hardness also showed greater toughness.

We found something similar with 5160. I’m finding that most low alloy steels do well when quenched from 1525’, the exception is O1 and O2.

Hoss

This is interesting. I found 1460-1470f works for 15n20, 1460f for W2, 1475f for both 1095 and Aldo’s 1084, 1475f for O1, and 1475-1500f for 1075. On the other hand, 8670 and 80crv2 work better at 1525f.
 
This is interesting. I found 1460-1470f works for 15n20, 1460f for W2, 1475f for both 1095 and Aldo’s 1084, 1475f for O1, and 1475-1500f for 1075. On the other hand, 8670 and 80crv2 work better at 1525f.

W2, 1084, and 1095 are simple carbon steels and do require lower aus temps. O1 is a tool steel and does have a lower range. 8670, 80crv2, 5160, 52100, 1.2519, 1.2562, L6, L2, etc. are low alloy steels that do well at ~1525. 15N20 is the odd man out, nickel and carbon are about the only alloys in it. Nickel does lower the A1 and A3 temperatures also lowering the quench temperature.

Sometimes knife makers use the words carbon steel, low alloy steel, and tool steel interchangeably. There is some overlap in these terms but in general, carbon steels require lower aus temps than low alloy steels.

Hoss
 
W2, 1084, and 1095 are simple carbon steels and do require lower aus temps. O1 is a tool steel and does have a lower range. 8670, 80crv2, 5160, 52100, 1.2519, 1.2562, L6, L2, etc. are low alloy steels that do well at ~1525. 15N20 is the odd man out, nickel and carbon are about the only alloys in it. Nickel does lower the A1 and A3 temperatures also lowering the quench temperature.

Sometimes knife makers use the words carbon steel, low alloy steel, and tool steel interchangeably. There is some overlap in these terms but in general, carbon steels require lower aus temps than low alloy steels.

Hoss

Thanks for the clarification.
 
With Aldo's 52100 I have always been very pleased with the end results. What I don't like is what it takes to get there (normalizing and cycling). I've not used any 52100 over 0.110" in thickness ever, whether that was Aldo's or Chuck's (AKS). Aldo's 52100 always would get screaming hard for me after the normalizing and cycling (1700f 20 minutes, then 1500f 10 minutes 3x, then 1475F 10 minutes P50 or canola quench, 66 HRC every time). Then I heard Chuck mention that his 52100 was fine spheroidized (compared to Aldo's coarse spheroidized), and tried some in 0.090" and 0.050" (paring knives). 1475F 15 minutes, P50 or canola quench, 66HRC as well.
 
With Aldo's 52100 I have always been very pleased with the end results. What I don't like is what it takes to get there (normalizing and cycling). I've not used any 52100 over 0.110" in thickness ever, whether that was Aldo's or Chuck's (AKS). Aldo's 52100 always would get screaming hard for me after the normalizing and cycling (1700f 20 minutes, then 1500f 10 minutes 3x, then 1475F 10 minutes P50 or canola quench, 66 HRC every time). Then I heard Chuck mention that his 52100 was fine spheroidized (compared to Aldo's coarse spheroidized), and tried some in 0.090" and 0.050" (paring knives). 1475F 15 minutes, P50 or canola quench, 66HRC as well.
On the Alpha website the thickness I am using (.188) is the only thickness that as specified as Bohler steel. I wonder if all the other thickness is from Latrobe. There isn't a huge difference in composition, but the Latrobe has .05% more carbon and .05% more manganese...
 
I looked at my workbook, and I did do 1550f with 52100 for one sample, but used cryo on it. It’ll be interesting to see results.
 
Has anyone been using Chucks 52100 without all the cycling? Wouldn't it still be a good idea not necessarily because of the spheroidization but to control carbide size?
I'm out of my lane here, but I'm trying to keep up with you guys!
 
I read through that entire thread and thought I was ready to go. Seems like every steel needs separate directions for Aldo's and not Aldo's. I was recently gifted some of his W2 and from what I read here, I'm not sure what to do with it.
Depends on the vintage. If it's recent I would test some coupons using the usual protocol plus the high heat normalization protocol that was in a recent thread. I had to go to 2000 X 10min normalize, 1500 X 10min X 3 then Aus at 1500 to get RC65-66 consistently across the coupon. I still need to Aus at 1525 to see if that's better but haven't had time yet.
 
Depends on the vintage. If it's recent I would test some coupons using the usual protocol plus the high heat normalization protocol that was in a recent thread. I had to go to 2000 X 10min normalize, 1500 X 10min X 3 then Aus at 1500 to get RC65-66 consistently across the coupon. I still need to Aus at 1525 to see if that's better but haven't had time yet.
I'm sure its the new stuff. I only was given enough for 1 blade so it's gonna be a toss of the dice if I want to use it for something. (Texas Farrier Supply threw in in along with some other freebies due to a delayed order, good dudes over there) So, I'll probably make something for myself using the above process and see what happens!
 
Has anyone been using Chucks 52100 without all the cycling? Wouldn't it still be a good idea not necessarily because of the spheroidization but to control carbide size?
I'm out of my lane here, but I'm trying to keep up with you guys!

Chucks 52100 is ready to harden as received. There is no need to normalize it, but if you want to try grain refinement thermal cycles go for it. But I think you’ll find the grain structure “as received” won’t be significantly improved upon by thermal cycling.
 
Has anyone been using Chucks 52100 without all the cycling? Wouldn't it still be a good idea not necessarily because of the spheroidization but to control carbide size?
I'm out of my lane here, but I'm trying to keep up with you guys!

The fine spheroidizing breaks up nicely at austenitizing temps and soaks. It’s the extreme course spheroidizing that takes higher temp not just longer time. My experiment 5 years ago showed time alone at normal temps wasn’t enough. Aldo’s steel needed temp increases to break up the carbides. I didn’t understand the difference between course and fine spheroidizing when I did the experiment. It made more sense after I did my experiment, and then talked with Kevin Cashen at a hammer in. From what I understand, course spheroidizing is the normal condition from the mill in most cases, and takes between 10-15 min to break up at “normal” temps. This is the condition of the steel after a full anneal, heating above ac1 and slow cooling at a rate described in the datasheet, like 25f/h iirc. Aldo’s steel is different. I’m not sure what process results in his steel condition. Fine spheroidizing results from a subcritical anneal, 1200f for 2h for example.
 
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Has anyone been using Chucks 52100 without all the cycling? Wouldn't it still be a good idea not necessarily because of the spheroidization but to control carbide size?
I'm out of my lane here, but I'm trying to keep up with you guys!

My friend uses the .13" 52100 from Chuck all the time for stock removal chef knives. I have seen it quench for 66+ from 1525 into parks50 with no normalizing. Just 12 minute soak and quench.
-Trey
 
Has anyone been using Chucks 52100 without all the cycling? Wouldn't it still be a good idea not necessarily because of the spheroidization but to control carbide size?
I'm out of my lane here, but I'm trying to keep up with you guys!

I always buy the .18 and forge though, my routine is
1650, 1600, 1510
Quench from 1525 into parks
-Trey
 
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