Haet Treatment ATS34?

nozh2002

nozh2002

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I was asked from my Russian friend about HT of ATS34.

I run google and found two confusing quotes:

1. Heat the metal quickly to 1975F (1079C), leave it at that temperature for 40 minutes. Quench with liquid argon to -120F (-84C). Straighten the blade if necessary. Freeze the blade to -220F (-140C) and leave it at that temperature for eight hours. Heat the blade to 950F (510C) and maintain it at that temperature for two hours, allow it to cool quickly to room temperature, then reheat quickly to 950F (510C) again, maintain at that temperature for two hours again, and cool slowly to room temperature. This will result in a hardness of 59-60 Rockwell.

http://www.balisongcollector.com/rockwell.html

2. Heat to 1975 degrees F and soak for 40 minutes. Quench in Argon or rapid quench in air, straighten as necessary before freezing to 120 degrees F, than freeze to below 220 degrees F for 6 - 8 hours to transform retained austerities. Double temper at 950 degrees F, 2 hours for each temper. This gives a final Rc of 59 - 60.

http://ajh-knives.com/metals.html

So my question is quenching suppose to be in Argon or liquid Argon and to 120F or -120F.

I guess second is correct only it should be -220F in liquid nitrogen?

Thanks, Vassili.
 
And here it is oil quenching... What kind of oil (fast, medium)?

ATS 34, 154CM S.S. Heat Treat Procedure: Special Thanks to Koval Knives for this Information

This is an oil hardening grade of steel which will require oil quenching. The oil should be warm, thin quenching oil that contains a safe flash point. Olive oil has been used as a substitute. As a rule of thumb there should be a gallon of oil for each pound of steel. For warming the oil before quenching you may heat a piece of steel and drop in the oil.

1. Wrap blades in stainless tool wrap and leave an extra two inches on each end of the package (This will be for handling purposes going into the quench as described below). We suggest a double wrap for this grade. The edges of the foil should be double crimped being careful to avoid having even a pin hole in the wrap.

2. Place in furnace and heat to 1900°F. After reaching this temperature immediately start timing the soak time of 25 to 30 minutes. Evenheats' Set-Pro control can be programmed to automatically soak, for any amount of time desired, once temperature is reached.

3. After the soak time has elapsed, very quickly and carefully pull the package out with tongs, place over the quench tank and snip the end of the package allowing the blades to drop in the oil. You should have a wire basket in the quench tank for raising and lowering the blades rather than have them lie still. Gases are released in the quench and would form a "trap" around the steel unless you keep them moving for a minute or so. IMPORTANT - It is very important that the blades enter the oil quench as quickly as possible after leaving the furnace! Full hardness would not be reached if this step is not followed.

4. After the blades are quenched down to near room temperature (preferably around 125°F) they must re-enter the furnace at 300°F. After they reach 300°F allow them to remain for 2 hours. Evenheats' Set-Pro control can be programmed to automatically soak, for any amount of time desired, once temperature is reached.

5. Remove blades and place them aside for room temperature cooling.

6. After they have cooled to room temperature, place them back in the furnace at 275°F for 2 hours. Remove and check hardness. You should have approx. 60 RC. Evenheats' Set-Pro control can be programmed to automatically soak, for any amount of time desired, once temperature is reached.

7. For extra stability and a point higher hardness you may pack blades in dry ice for one hour.

Note: All the above procedure is based on our own experience realizing there are others using their own trial-error. All equipment must be calibration checked periodically. There are no "short-cuts" for proper heat treating. Always exercise care and precaution.
 
Typically here makers use liquid nitrogen rather than argon .It's readily available and probably cheaper.Some also use a dry ice/acetone mix for -100 F. Many are now using a 'plate quench' rather than oil .Take the blade still in stainless foil and quench between two aluminum plates.Do a search here for other discussions. I would temper at 400 F.Also check www.crucibleservice.com for 154CM info.
 
ok first off the ht of ATS34 is something I send out but...1540 for 40 min and then it is blasted with compressed air(argon is non reactive) then when it is room temperature it is dipped into liqued nitogen thissub zero quench relives the stress in the blade and give it another 1-3 points of RC without increasing the brittleness of the steel.(acetone and dry ice is some times used acording to Wayne Goodard's Joy of knife making.
 
I have recentlly found a good artical in BLADE magazine outlineing the heat treat,tempering, anealing of popular steels includeing ATS-34. It is in APRIL 2007 hope this helps
 
ciphery,
I don't think 1540 will do much for ATS34. 1950 is about the bottom.
Stacy
 
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