Proper Quenchant for 80crv2- Parks #50 or AAA?

Heikki

KNIFE MAKER
Trying to figure out if Parks #50 will work to quench 80crv2, or if I need to pick up some AAA. After reading through the forums, looks like both have been used with success.
 

tkroenlein

Well-Known Member
Looks like a lot of people get away with P 50, but AAA is what it needs. I use a quenchant that is rated at 10.2 sec @ 78F.
 

Kevin R. Cashen

Super Moderator
The question of oil to use for the steel is actually very simple- ask yourself if, under any circumstances, you would feel safe quenching that steel in water. #50 was made to replace water with is quench speed, if quenching your chosen alloy in water gives you pause, Parks #50 is probably too fast. Now, the idea of quenching 1075 in water does make my teeth itch, but under the right circumstances, with careful preparation, I would attempt it. But under no circumstances, for any reason, would I put hot 80CrV2 into water. Even if it survived, you wouldn't want to see some of things it did to the inside of that steel.
 

tkroenlein

Well-Known Member
I wonder if there is a significant reduction in toughness using a faster quenchant than is needed.
 

Andre Grobler

Well-Known Member
Possibly, but higher rates of distortion would be just the first hurdle to overcome. Let's put this one to bed, shall we:
View attachment 77738
Parks #50 was designed for the likes of 10XX series and W series, this alloy has a cooling curve over 9 times slower than those steels.
Kevin - Iam curious to know what it does to the steel in quenching too fast... we struggle to get good oils here, you dont actually know how fast it is... some oils we have, that say they are for water quenches, but 3mm 1085 doesnt harden... so it is a bit hit and miss... distortion is one, O1 i did an experiment in water, gained a point as quenched, also warped a 2x1x0.2" piece of O1... but in the fastest oil we get, it was at least 1 hrc point lower than water and straight... any other oil and i get even lower hardness, not much, maybe 64.5 - 65 instead of 65.5-66 as quenched... this after some grain refinement. water was 66.5 and a little above on the test sample, only did it at one temp, not at the variety like the others. so i am using the fastest oil i can get for O1, and 80crv2, but is there anything else one can test or see, that will tell you the oil is too fast? - i don't notice any real brittleness, but that is difficult to quantify.
 

mpcoppin

Member
I've successfully used Canola Oil for 80crv2 steel.
I also use canola for 80CrV2 but I’d put an * by “successfully” because my observations of success are purely anecdotal. To me, it skates a file and it feels like it’s really hard but I can’t give any numbers or objective data to quantify my success.
 

Justin Presson

Well-Known Member
Kevin Cashen, Is there a simple chart/spreadsheet that has a list of steels and what oil or quench method is recommended? I see alot of heat treat recommendations on websites that state quench in oil.
I'm probably not versed in HT enough to know which steels needing a fast vs a slow.
 

Kevin R. Cashen

Super Moderator
An extra .5 to 1 point HRC at the top end of the range of an alloyed steel from water would be the result of added strain during the direct conductive cooling phase of the quench, strain above and beyond that which is required for the continued martensitic transformation that is occurring in this range. e.g. if you cold hammered the same blade you would also gain a point, regardless of the pearlite to martensite ratio. I have managed to max out HRC in most steels I have worked with simply by zeroing in on the optimum austenization, while using the same oil.

Justin, a whole chart may not be needed to express alloyed = oil (medium speed) , simple carbon = water (fast oil). Anything beyond .25% Cr, or above 1% Mn is probably going to be oil hardening (medium speed). 1075, 1080, 1084, 1095, W-1, W-2 = Fast oil. 5160, 52100, 80CrV2, O-1, L6, 8670M etc. = Medium oil. But this list is requested enough that I believe I will add such a chart to my webpage, when I get back from Blade, if it will help.

Sadly, the internet is more rife with bad knife heat treatment information than ever. I recently had a maker contact me to help him understand which oil to buy since the supplier's literature had the steel to oil matches totally reversed from what they should be. I feel bad for all the folks who had spent money on a medium speed oil for 10XX only to have to spend it again on the correct product.
 
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Justin Presson

Well-Known Member
An extra .5 to 1 point HRC at the top end of the range of an alloyed steel from water would be the result of added strain during the direct conductive cooling phase of the quench, strain above and beyond that which is required for the continued martensitic transformation that is occurring in this range. e.g. if you cold hammered the same blade you would also gain a point, regardless of the pearlite to martensite ratio. I have managed to max out HRC in most steels I have worked with simply by zeroing in on the optimum austenization, while using the same oil.

Justin, a whole chart may not be needed to express alloyed = oil (medium speed) , simple carbon = water (fast oil). Anything beyond .25% Cr, or above 1% Mn is probably going to be oil hardening (medium speed). 1075, 1080, 1084, 1095, W-1, W-2 = Fast oil. 5160, 52100, 80CrV2, O-1, L6, 8670M etc. = Medium oil. But this list is requested enough that I believe I will add such a chart to my webpage, when I get back from Blade, if it will help.

Sadly, the internet is more rife with bad knife heat treatment information than ever. I recently had a maker contact me to help him understand which oil to buy since the supplier's literature had the steel to oil matches totally reversed from what they should be. I feel bad for all the folks who had spent money on a medium speed oil for 10XX only to have to spend it again on the correct product.
Thanks for the info Kevin this helps.
 
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