Been a bit since I posted! Just getting back to my normal job after a week "vacation" in my shop!
Forged down the remainder of a 144 layer 125CR1/15N20 billet I started last year, and profiled out 5 knives:
First HT attempt at 1475 didn't harden (they were high 40's) with ATP641 in parks 50, so I tried again w/o the ATP641. Same result. Bumped up to 1500, nice quenching sound from the Parks 50 and nice and hard, mid to upper 60's out of the quench!
I noticed my HT oven is taking longer and longer to heat up and the thermocouple block is pretty charred. Decided it was time to redo my HT oven!
Got the 3" K23 bricks this past summer, so I cut the bottom layer down to 7" wide, milled the grooves in the tops of the other bricks for the quartz tubes to support the coils, pulled and stretched and bent the coils, welded up the frame:
Cut grooves into the bricks for the element pigtails to come out of the oven. The top layer bricks cover the grooves:
Rigged up a "door" by stacking firebricks on some angle iron:
I originally put a shorter thermocouple in from the side of the oven, bent it so it would go around 1" from the wall, about 3" length along the wall in the middle. Cheap thermocouple, maxed out at 1530-1570, even after running for a couple hours. Grabbed by old TC out of the old oven, tried that, but it was all over the map and the ceramic block was charred. Found another TC and new block, set it up, now it works! The other fire bricks were letting a lot of heat through; the oven got slower and slower every heating, so something wasn't working right! I noticed that the element connectors were also charred and they were right on the bricks, just like the TC block was.
Did a test run with the new TC/TC Block with the bricks on the angle iron as a door, went much better! 1450 in 30 min, 1505 in 35 min, ended up at 2150 in 130 minutes; previously, it was almost 3 hours for the other oven to get up to temp. And that was just with some old Kaowool along the top of the oven, not the sides or bottom!
So I got the door made and door frame welded and installed with hinged to the oven frame, handle, door contact switch and spring closure also installed, wrapped with 1" of Superwool all around, with 2" on the right side and top (left was tight to the frame) and wrapped aluminum flashing around the oven as well. The welding was so much easier this time with the newer Azzuno Mig welder and fluxcore wire...once I remember to put the machine on the fluxcore and not CO2 setting!
Got the last of my SKS blanks finished off with the carbon fiber/Red G10 marble and red kryptek sheath and a ProCut drop point with black bolster and bluish/green stabilized burl handle. Steel info on the other side of the knife has been working well!



