How to Heat Treat 80CrV2 Steel

80CrV2 (1.2235) (AISI L2) is a relatively new steel for South African knife makers (2020). However, it is popular in northern Europe (Finland) as Swedish saw steel and has seen growth in the US since 2014 thanks to efforts by Dan Winkler and more recently MS Jason Knight of “Forged in Fire” fame.

80CrV2 is a low alloy tool steel/spring steel for cold work. Primarily used for carbide-tipped saw bodies, circular saw blades, solid tooth saw bodies for agricultural use, pruning blades, gardening tools, friction saws, frame saws, and log saws (paper roll cutting).

80CrV2 Chemical composition (nominal) %:

C 0.85, Mn 0.50, Cr 0.60, S 0.010, P 0.025, Si 0.35, V 0.25

It provides the essential qualities of 1080-series steel, with all the toughness perks of high chrome steel like 5160. In fact, it’s been referred to as “5160 on steroids” as the extra carbon, and added vanadium can help it achieve a higher hardness and therefore better edge retention at the expense of some overall toughness. It is often used to make knives that require exceptional strength to handle tough applications like tactical knives, hunting knives, axes, and swords.

Here is a composition comparison graph of the steels that are usually compared to 80CrV2 (ie: 5160, L2, 1084, O1) (visit zKnives.com).

Heat treatment

NB! It’s important to protect the steel from oxidation and decarburization during hardening. Cordusal, Turco, ATP-641, (anti-scale compounds), and/or stainless steel foil (during annealing) are probably the best choice unless you don’t want to spend time removing the affected surface post-heat treat.

80CrV2 can take a decent hamon when refractory cement/clay or other high-temperature coating is applied prior to final austenitization (Read: Hamons, what are they and how to make them).

Thermal cycling (optional):

  • An often overlooked step, but due to its susceptibility to warping during oil hardening, an annealing step can save you countless headaches.
  • 80CrV2 reportedly comes heavily spheroidized (dependant on the supplier), so in order to get good results you have to normalize and thermal cycle the steel before heat treatment. This is particularly important for stock removal makers who would normally not have to refine the grain in their steels.
  1. Normalizing: Heat the blade (830°C/1525°F) in the furnace and hold for 10 minutes. Allow the blade to air cool to room temp. The resultant microstructure ideally will be pearlite [3].
  2. DET (Divorced Eutectoid Transformation): Heat the blade (760°C/1400°F) for 15 minutes, and allow the blade to cool in air. Unlike the above, we are looking for ferrite and carbide structures [3].

Austenitizing / Hardening

  • Hardening Temp (Furnace): 830-880°C [1,525°F – 1615°F]
  • Sweet spot: 840°C [1544°F]
  • Soak time: 5min (2.5mm) to 10min (5mm)

Quenching media

  • Fast-speed oil is recommended until the part is black.
  • Some sources recommend water (I assume heated brine) for thicker cross-sections – use a lower autenitizing temp (reduce the danger of cracking)
  • Aluminum plates can be used as a secondary quench step to minimize any warping.

Tempering

80CrV2 Time Temperature Transformation and temper diagram
  • Tempering Temp:
    • 62HRC: 150°C (300°F)
    • 61HRC: 180°C (350°F)
    • 60 HRC: 200°C (400°F) Do not temper higher as it can lead to tempered martensite embrittlement and lower toughness scores. [2]
  • Times: 2 times
  • Duration: 2 hours each time

Recommended Hardness: 58 – 60HRC (after tempering) depending on the intended use. Lower HRC is recommended for tough prybars and higher hardness for sharp slicers that will see little chopping.

Disclaimer:

Please note that there are various manufacturers of 80CRV2 whose tolerances/chemical composition will differ quite a bit, making exact heat-treatment specifications difficult to pinpoint for everyone. Your own heat treating kiln will also differ in its readings compared to mine. As such it’s best to do your own testing (coupons). All info above is from my readings of research papers, forum posts, and discussions with people. I am not a metallurgist and the above is presented here for the benefit of all knifemakers. You do not have to follow them and I’ll not be held responsible for any loss or damage you may experience.

Please comment below if you have anything to add to the above.

Links / References:

  1. Reader Question – O1 vs 80CrV2
  2. Ranking Toughness of Forging Knife Steels
  3. How to Thermal Cycle Knife Steel

Leave a Reply

Your email address will not be published. Required fields are marked *