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52100 Problems

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by E.Carlson, Mar 25, 2019.

  1. E.Carlson

    E.Carlson KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    649
    Mar 28, 2016
    I recently got my first batch of 52100 from Alpha. I've been looking for a go to steel for thicker blades (3/16) and was interested in trying the low temp aus. Since it was from Alpha, I normally would go straight to quench, but had some doubts because I was planning on a non-standard heat treat. Tried a small coupon for fun: 1475 for 20 min, quench in P50. Tested anywhere from 60-65, Different reading in each spot. I didn't find this too surprising, so I took the blade I was working on and followed what I understand to be the proper treatments:
    1650 air cool
    1500 air cool
    1400 air cool
    Aus :1475, 15 min, quench P50. (I let my oven pre-heat to 1475 and stabilize for 1 hour.)
    Ground the tang clean and tested at 62 consistently. Not the 66-67 I was looking for.
    So, I'm guessing my oven may be reading a tad off and it it time to make a batch of coupons to nail this down. My question is, since the blade did harden, just not to the extend I need, does that tell me what direction to go in temp? Should I try a lower temp too? Maybe see what a 1425 coupon does along with 1500, 1525 & 1550?
    Does anyone get their 52100 from Alpha?, If so, what works for you? Most the old conversations seem to be discussing Aldo's steel.
     
  2. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    Try 1500f. Larrin recently did some tests with 52100, and 1500f was the sweet spot. Aldo’s 52100 seems to be its own animal.
     
    E.Carlson likes this.
  3. comet_sharp

    comet_sharp

    229
    Aug 22, 2016
    1475 is far too low for 52100 unless youre looking for 58 tempered.
    1525 into parks 50 or 1540 into medium oil is where you will start to see those 66/67 quench numbers. Source and previous state of steel should matter little for 52100 as the addition of chrome to the steel requires higher temps than 10xx series. Previous state will make a difference with soak time and final grain size.
    Id cut 2 coupons and do 1525 and 1540 into fast quench oil and go from there.
    -Trey
     
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  4. E.Carlson

    E.Carlson KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    649
    Mar 28, 2016
    I'd forgotten that Larrin just did an article on 52100.
     
  5. DevinT

    DevinT KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jan 29, 2010
    I did the heat treating on the 52100, 1500-1525 was best for hardness and toughness.

    Hoss
     
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  6. comet_sharp

    comet_sharp

    229
    Aug 22, 2016
    Good to hear coming from you. I tried 1475 when first dabbling with 52100 and it never hit the hardness I wanted. Toyed with it for about a year and landed on 1525 into parks 50 for my chef knives.
    -Trey
     
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  7. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    I did extensive testing on Aldo’s 52100 years ago. The condition of the steel definitely plays a roll. The steel was so heavily spheroidized it wouldn’t harden even with a 30 minute soak. Secondly, aldo’s 52100 is almost 0.1% lower carbon than other sources. It requires different heat treating than other sources. Aldo’s steel gave me Rc66/67 with 1475f 10 min soak, quenched in DT-48, after normalizing andthermal cycling.
     
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  8. Maelstrom78

    Maelstrom78

    Sep 21, 2013

    Huh that explains my soft 52100 chef that I did at 1475 into canola.....
     
    Willie71 likes this.
  9. E.Carlson

    E.Carlson KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    649
    Mar 28, 2016
    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.
     
  10. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
  11. Kentucky

    Kentucky KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider Basic Member

    Dec 13, 2008
    Same here. I use to use a lot of Aldo’s 52100 and it would consistently hit 66/67 when austinized at 1475°. That was quenched mostly in McMaster Carr fast quench
     
  12. comet_sharp

    comet_sharp

    229
    Aug 22, 2016
    I have read about 52100 quenching for 66/67 at 1475, I have just never seen it actually work. 1475 into fast oil would quench higher than using medium oil but still not as high as 1500-1525. This is also trying aldos 52100 and cold rolled 52100 from bohler. Spheroidizing is generally a good thing as far as I am concerned, so for that state of Aldos steel I do not know...
    My rule of thumb is spherodizing helps if you can control a soak and hardening from pearlite is easier if not.
    Also everyone's equipment is different, my thermocouple reads 14° high and i adjust according.
    -Trey
     
  13. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    There’s a difference between course and fine spheroidizing. Fine breaks up easily, course takes longer. At extreme ends, you need more heat to break it up. I suspect Aldo gets his steel expecting it to be forged, so the original condition doesn’t matter as much. It creates problems for us stock removal guys. Your statement that 1475fis only good for Rc58 after tempering is simply false. I got Rc62 on Larrin’s tester on one of the charpy samples, using 1475f, tempered at 300f.

    Maybe Aldo has a newer batch of steel in 52100 that requires different heat treat than we used 5 years ago? Much like his W2?
     
  14. jdm61

    jdm61 itinerant metal pounder Knifemaker / Craftsman / Service Provider

    Aug 12, 2005
    Are my math skills really bad or does the Bohler 52100 that Alpha has sell for like $12 a pound? Aldo looks like he is selling for around $8 a pound. You do pay for the opportunity to buy flat 52100 like other steels. Ray Kirk still has his 52100 round bar listed for $4-5 a pound depends on the bar size. Interestingly, his stock is like .93% carbon for his big bars and over 1% for the .535 stuff that he found in Georgia IIRC.
     
  15. DevinT

    DevinT KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jan 29, 2010
    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
     
  16. comet_sharp

    comet_sharp

    229
    Aug 22, 2016
    Like I said that low temp has just never worked for me regardless of steel or setup. The bohler stuff is .18" and consistently tested better for me so i switched to it, I also forge. It makes me curious of the Cr content though in the 52100 getting hard so low.
    -Trey
     
  17. comet_sharp

    comet_sharp

    229
    Aug 22, 2016
    This has been my experience so far as well.
    -Trey
     
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  18. comet_sharp

    comet_sharp

    229
    Aug 22, 2016
    As far as spheroidizing goes I would assume most mills would do a recommended anneal within steel manufacturer temp range to ensure good structure. Never considered sub critical annealing steel with poor structure before as it seems silly.
    Sorry for the multi posts in a row, scatter-brained day watching the kids :confused:
    -Trey
     
  19. E.Carlson

    E.Carlson KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    649
    Mar 28, 2016
    Went with 1525 and tested at 65-66. That will work for me.
    20190325_183331-2268x2268.jpg
     
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  20. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    I was thinking the same thing. The lower carbon should have raised the austenitizing temp, not lowered it. That thread from a few months ago talking about getting certs with steel is really resonating with me.
     
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