Stock Removal 52100

J

jawilder

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Jun 27, 2006
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I have read where the forging requires multiple quench cycles but haven't read anywhere about the need for the multiple quenches for stock removal. No doubt that's because before now 52100 HAD to be forged. But thanks to Aldo, that's not true any more.

Suppose I got some thin 52100 from Aldo that was already the thickness I needed and only needed to profile and grind to shape... How would the heat treat be different from if I were to forge it?

Thanks,
Jason
 
Heat treat dosnt have to be different either way friend...A 20 minute soak at about 1500* then quenched in medium speed oil..Kevin Cashens notes there and Ive found it to work excellent..
 
All work done on steel adds stress. It is a part of HT to remove these stresses before hardening....irregardless of how it was shaped.
 
Question for Aldo: I understand you sent 52100 bar stock off to a rolling mill to make sheets. Was the stock annealed afterwards?
 
all of aldos steel comes anealed (sept maybe the H13 )
when you send to the rolers its part of the prosess to re anneal
 
I recently ground three blades out of Aldo's 52100. I'm certain it was indeed fully annealed, it was very easy to grind. Very clean, too.

I'm no HT expert, but I don't think a stress-relief cycle after all the grinding is done is ever a bad idea.
 
I spoke with Aldo today and he confirmed that any steel such as 52100 or O1 should be run through a full thermocycle before HT because of all the stresses that come from rolling.
 
The main reason to multiple quench 52100 is that research has shown it forms martensite most effectively when quenched from a previously martensite state. I'd think there's no difference between forged or stock removal in this regard.
 
Some, like Mister C, says that the triple quench may had been devised to fix what people had messed up in the forging and rudimentary heat treat and make sure your converted everything to martensite.
Salem Straub said:
The main reason to multiple quench 52100 is that research has shown it forms martensite most effectively when quenched from a previously martensite state. I'd think there's no difference between forged or stock removal in this regard.
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jawilder said:
I spoke with Aldo today and he confirmed that any steel such as 52100 or O1 should be run through a full thermocycle before HT because of all the stresses that come from rolling.
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According to Mete', PG spheroidized annealed 01 needs no more than a stress relief pre-heat if not forged. Why would 52100 be different, assuming it was already spheroidized annealed? What would be gained by heat cycling if not forged?
 
LRB said:
According to Mete', PG spheroidized annealed 01 needs no more than a stress relief pre-heat if not forged. Why would 52100 be different, assuming it was already spheroidized annealed? What would be gained by heat cycling if not forged?
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The grinding process develops heat, and uneven @ that, this would induce stress
 
LRB said:
According to Mete', PG spheroidized annealed 01 needs no more than a stress relief pre-heat if not forged. Why would 52100 be different, assuming it was already spheroidized annealed?
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It's not the 52100. Aldo is sending industrial plate off to rolling mills to re-roll it into sheet. Any plate that's re-rolled would need to be annealed, ideally spheroidized.

Sounds like Also is saying we should be annealing his re-rolled stock? That would include 52100, W2, ...
 
I would not expect/assume any steel bar stock to come freshly annealed (without subsequent rolling/processing) unless it is specifically sold that way. In many cases you can drill and grind bar stock easily enough as it comes from the mill, but this does not mean it was annealed, it just means that it wasn't hardened, and you didn't hit any large concentrations of carbides with the drill.
 
I definitely do NOT want to drift this into some HT controversy thread, much of it seems to surround 52100. Just wanted to dig up a bit more from a different perspective. I'm still looking for the objective science out there.

Some, like Mister C, says that the triple quench may had been devised to fix what people had messed up in the forging and rudimentary heat treat and make sure your converted everything to martensite.
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-Joe Mandt

Joe, I do have enormous respect for Mr. C., and I'm sure in many cases what you mention is the primary benefit. I'm not at all sure though that the rewards stop there, if you know what you're shooting for with 52100.

Pasted from elsewhere on the web:
The theory behind the triple quench is that by bringing the blade rapidly up to the hardening temperature, the grain size remains smaller then when the usual soak time is used. The soak time allows all the transformations to be made within the steel, yet the grain grows with the additional time at the soak temperature. With the rapid quench the transformation is not complete, however the second and third quenches complete the necessary transformation.
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Not sure who said that, possibly E.F... and I definitely don't subscribe to everything else that goes with it from those guys. But, it does make sense to me, and I do 3-quench my 52100. I do evenly heat the entire blade, and oven temper twice, then soften the back with a torch.

I've recently tried single quenching several 52100 blades in P50, then giving them the same tempering regimen as my other 52100. I've not finished them out yet for cut testing, I'm interested to see what the difference may be.

I've seen results of an experiment posted where the OP deliberately overheated the steel to increase grain size, then tested single and multiple quenching, successfully reducing grain size more significantly with triple quenching. That's informative, but not satisfying to me, as the steel had been overheated. I'd like to see the results of the two quench methods compared on 52100 never brought above the correct temp. Anyone aware of such a test having been done? Like, with a salt pot or kiln, not a torch?
 
From Verhoeven-page 69. My understanding is that multiple quenches have the effect of reducing grain size as long as the austenizing temperature is not too high and the steel is not austenized for too long a period of time. If your annealed pearlite structure is fine to start with and you austenize and quench properly, your austenite grain structure will be very fine to ultrafine when you finish. This in turn should lead to a much finer martensite grain structure of predominately lath martensite. 52100 was not cited in the text but the model should still apply. 1086 was cited and went from a grain size of 11 to a grain size of 15.
 
Here is a post directly from Kevin C. about 52100..Ive started following this advice on 52100 and I can tell a difference in quaility..Trust me, Im not one to blindly follow advice from anyone but all the advice Ive gotten from Kevin has been spot on after testing..
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52100 is all about the carbide, when you have at least .3% extra carbon you don’t have much choice. If you want to maximize the stuff you need to pay attention to those carbides. In this area your heat treatments before hardening will be at least as important as your final heat and quench. In normalizing you want to go hot and put all of that carbide into solution and then cool quick enough not to have it go out of solution in a coarse form and certainly not in the grain boundaries. So the vermiculite, wood ash or leaving in the cooling forge is out of the question. Also be certain to get it hot the first time and then air cool quickly, in normalizing. Reheat a couple more times going cooler as you go. The best phases to go to the final heat treat with would be upper bainite, very fine pearlite or very fine spheroids with martensite as a last resort. Coarse pearlite or large spheroidal carbides would not be desirable.

If you do things correctly you can leave the extra carbide very finely dispersed throughout the matrix to give very good abrasion resistance with no embrittlement problems. On heating for the quench the high end will put much of those fine carbides back into solution and, as mete pointed out, result in retained austenite. I have done soak temperature experiments that show Rockwell hardness climbing steadily with every 20F less from the upper range until you drop below 1475F and then undersoaking occurs. I have managed to get 67HRC from 52100 but the strain and embrittlement becomes a problem.

If you manage to put around .7%- .8% carbon into solution for the quench and leave the rest as very fine carbide, you will achieve maximum hardness with excellent abrasion resistance and little embrittlement, but this will be determined mostly by your prior treatments. Very little can be done with carbides in the final heat if they were not ideal before. With the alloying present you can also increase this effect a bit with tempering as secondary carbides are formed. It is this factor that is responsible for all the unorthodox things that many smiths come up with for this steel, which really ammount to so many forms of what I call "carbide games".
 
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