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154CM

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Hey guys so I aint been around the past week or 2 but back and I have a question. so most of my stuff I have done has been 440C. of corse I started with 1084 and still use that once in a while. recently I have done 2 blades in CPMs35vn by first quench in oil just for a few seconds and then finish with a positive pressure but spraying air in a lil enclose, worked out well. I just got some 154CM (NOT the cpm version just the 154cm although it is made by crucible) so I want to heat treat a blade with this later today now I know basicly you try to heat treat to the hardness point and get it as hard as you can before it starts chipping so obviously different steels can take different hardness for example the cpms35vn can be heat treated harder than 440c if I made the 440c as hard as I could with the cpms35vn the 440c would chip like crazy. so like I said I have never used the 154cm before and I am wondering how hard I should try to make it without having lots of chipping. I would guess it would fall inbetween the 440c and the cpms35vn I looked at the spec sheet and it the aim hardness is 55-62 now that's a BIG gap so just looking for some advice from you guys that have used 154cm before any advice would help. oh also I do have a dewar full of liquid nitrogen so it will be cryo'ed (I know that increases the toughness a lil bit) and the spec sheet says oil OR positive pressure (not both like the cpms35vn) or salt ANDair  SO my plan was to just quench in oil and my oil is parks 50.  I have a hardness tester so I can test the heat treat and get it right on (HOPEFULLY :) )

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Have you been testing the hardness on these stainless knives you've been quenching in oil? A general rule of thumb with stainless is to send it out for heat treat... how are you accurately controlling ramping, and what are you using to tell temperature?

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yeh theo I have a pretty large even heat oven ( this one  http://www.evenheat-kiln.com/?pg=models&c=17&p=82 )   I only got the hardness tester recently so when I started with the 440c I was stuck to using the brass rod test and other things like that (wich is actually a pretty accurate way of testing you wont know the number but you will know if the blade is too soft or to hard) ialso broke a blade or "coupon" every once in a while to check the grain size. since I got the hardness tester I have been testing the 400c and as I said 2 blades were done is cpms35vn. and since I got the hardness tester I have realized how accurate the spec sheet are. ya know the say do this or do that and they all have a graph wich will show depending on quench temp, temper time and temp what the hardness will be and from my experience so far with the hardness tester is that the spec sheets are very accurate, now for quenching I have parks 50 oil, also some thick aluminum plates for plate quenching (some steels can cool in air) and I also made a lil "enclose" I can use with pressurized air to do positive pressure quenches. about the only thing I cant do right now is salt tank quenching. I also have the liquic nitrogen for cryo, the positive pressure I have only done twice on the cpms35vn (actually it was oil quench for a few seconds and then positive pressure. since with that steel you need both fr the best heat treat) also I have found a lot of stainless has either air or plate quench as a option. and from the testing I have found plate quenching may make the steel SLIGHTLY harder than a oil quench but I did testing on that in the beginning and everything that was plate or air quenched when broken had a much bigger grain size so I would rather use oil.  the tougher the alloy of steel the harder you can make it without breaking that's what I was saying I can effectily make cpms35vn harder than I can with 440c. I assume the 154cm will fall in the middle of those 2 normally I would do the testing however its my uncles birthday and I want to make him a blade and the only steel that I have the thickness that I will need for his knife is 154cm so I need to get this knife done soon and don't have the time to do a bunch of testing to see how hard I can make it with out having the edge chip in use. that's what I was asking about how hard can 154cm be made. I think lacking time to test ill shoot for 60HRC hardness and hope for the best

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