I am using the new formula 1075 that i purchased in February. made a blade from it hopefully for my journeymen test knife and took a risk and did my first attempt at ashi lines, the blade went into Parks 50 and it no harden... and i figured out how to get full hardness from a clay quench from figuring it out last year. I may have over tempered it in my caution. however, I went into the water as a second quench with a similar setup and it hardened. I read on the ASM heat treating app that 1070( in my mind its close enough to 1075 to heat treat the same) needs water to fully harden, however, I have been told oil will work for blades. now my current understanding of the underdocumented clay quench is heat rises so the edge should cool and remain cool as long as the blade is in the quench medium as the boiling of the medium moves the heat away and i waited for the medium to stop boiling before I pulled out the blade. from doing enough clay quenches to have lost count i am fairly certain i did not over clay the blade as i made a couple of blades from the same bar of steel and it hardened just fine but they did not have the ashi lines. I know my oil is still good as it's still nice and clear. so is it that the new 1075 clayed with ashi just needs to be quenched in water to harden it.
Note: I gave my blade my patented did you crack test which is after tempering I hit it with hard a 2000 gram swiss pattern hammer in a guillotine fashion and as it's still in two pieces so I am not too worried about the bend test, iffy on the actually chop test, however, I do not have enough 2x4 to really go threw the whole thing so I will test it again after I finished the polishing of the blade. however, if the hamon turns out to be really beautiful i may have to make a lesser copy.
Kevin, no you do not need water to quench the 1075. Parks 50 will work fine at 80 degrees. Things to look at. How thick was your clay? How thick were the ashi lines? Are you sure the blade got to 1475 degrees? Temp of the oil? Can you show a picture of your clay layout? Was this 1075 from New Jersey Steel Baron? A lot of variables.
Brion
Brion Tomberlin
Anvil Top Custom Knives
ABS Mastersmith
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Kevin, no you do not need water to quench the 1075. Parks 50 will work fine at 80 degrees. Things to look at. How thick was your clay? How thick were the ashi lines? Are you sure the blade got to 1475 degrees? Temp of the oil? Can you show a picture of your clay layout? Was this 1075 from New Jersey Steel Baron? A lot of variables.
Brion
Sorry I just saw your response.,
the clay layout was similar to the as the cord wrapped blade which is only at 1000 grit and is the prototype for the failed blade made for the same bar of steel.
the blade melted my 1500F temp stick and according to the official ASM (International) HT guidelines for 1070, 1500 F is the hardening temperature (Note:1075 seems to be just a more controlled version of 1070 similar to w1 and w2...which would explain its price). the Temp of oil was likely 40F or 50F as I do not have a way to heat it my oil safely at this time which is why I use Parks 50 instead of AAA, I also had the ashi i think at the most it was 1/8th of an inch or less i had decanted my normal mixture of Rutland black, Marco red devil refractory, 4600KC steel powder(only kind I have right now) and a bit of terracotta which I use as a thickening agent when mixing if it gets too thin for my liking. the reason i bother mixing is i feel the as the mix does not puff up as much as Rutland black or Marco red devil, it's kinda fuzzy how thick i had the clay as i had to do it twice and may have over clayed it. however, it was also a fairly thick blade, to begin with as I would say roughly .230" at the flats and even with 1/8 inch clay it would still be over the size rounds can be oil quenched for full hardness which .250 is the thickest you can fully harden. it's likely I just put too thick a coating of clay on it. however, I did a practice run with a test blade made form the same bar of steel without ashi and it hardened just fine in my oil and I also checked and just rechecked my oil, and its still a healthy light amber color. the more likely reason is the fact that i clearly not thinking clearly gave 3 two hour tempering cycles for a grand total of 6-hours in the oven tempering. so I had a moment of stupidity and tempered out the hardness of the blade in my caution.
