- Joined
- Aug 7, 2018
- Messages
- 13
I have been using 5160 for my knives, but recently started trying some 1095 in hopes of getting a little more hardness out of my knives. Today's knife is 3/16" x 1 1/2" x 9" long. I finished all the grinding, sanded to 220 throughout and coated with ATP-641 prior to normalizing at 1650, 1550 & 1450 for 10 mins each. After normalizing the blade was badly carbonized. I attributed this to not waiting long enough for the ATP-641 to fully cure.
So, then I cleaned up the blade again and this time I heated the blade to 150 degrees and applied the ATP-641 again and put it into a 400 degree oven for 20 minutes to cure. Then I heat treated the blade at 1525 for 15 minutes and quenched in McMaster oil. Then I tempered the blade at 300 degrees for 1 hour 2 times. The blade measured RC 40 throughout.
This was a fail, so I did a second heat treat as below:
I cleaned up the blade from the last fail, sanding to 220 grit throughout. I heated the blade to 150 degrees and applied a watered down coat (approx 15%) of ATP-641 on the the whole blade. I then let it dry outside for 1 hour and then placed into 1525 oven for 15 minutes. Quenched in McMaster Slow speed oil.
RC (Pre-temper) measured 64 on the spine, but only 43 on the handle. I am actually ok with this outcome, but I didn't do anything different on the handle then on the spine. Everything was coated with ATP-641.
The blade tested non-magnetic at the quench (I tested it first, then put it back in the oven for 3 minutes before I took it out for the actual quench). I got it in the oil in less than 1 second and agitated properly.
I don't understand why the differential hardening?
So, then I cleaned up the blade again and this time I heated the blade to 150 degrees and applied the ATP-641 again and put it into a 400 degree oven for 20 minutes to cure. Then I heat treated the blade at 1525 for 15 minutes and quenched in McMaster oil. Then I tempered the blade at 300 degrees for 1 hour 2 times. The blade measured RC 40 throughout.
This was a fail, so I did a second heat treat as below:
I cleaned up the blade from the last fail, sanding to 220 grit throughout. I heated the blade to 150 degrees and applied a watered down coat (approx 15%) of ATP-641 on the the whole blade. I then let it dry outside for 1 hour and then placed into 1525 oven for 15 minutes. Quenched in McMaster Slow speed oil.
RC (Pre-temper) measured 64 on the spine, but only 43 on the handle. I am actually ok with this outcome, but I didn't do anything different on the handle then on the spine. Everything was coated with ATP-641.
The blade tested non-magnetic at the quench (I tested it first, then put it back in the oven for 3 minutes before I took it out for the actual quench). I got it in the oil in less than 1 second and agitated properly.
I don't understand why the differential hardening?