12-27-2017, 11:45 AM
Thanks a bunch, Mr Jan! Sorry I've been laid up for couple days.
Your scientific explanations are always incredible! That's like making science come alive. You're a great teacher!
Most of what I know relates to hardening and tempering of tool steel. The colors are supposed to be very accurate. You just need to know what color you're looking for. That's were it gets subjective, but experience will allow your eye to be very accurate.
For anyone heating steel in anything other than a knife kiln, there is one thing that is critical. It's actually so critical, that it's called "Critical". It's the austinization temperature, or the temperature you're looking for when you're trying to harden or normalize steel. Surprisingly, that color becomes easily recognizable.
I differentially harden most of my blades by heating the edge with an A/O torch, and a large welding tip. I have a a couple relevant videos that a friend took not long ago. One is of hardening the edge, and another shows how I draw the spine to spring steel. I'll have to try find to post them.
I just got a new laptop recently, and I didn't want to lose any information from the two cheap laptops it is replacing. I noticed I have way more pictures than I thought I did, so I'm trying to get them coordinated. I will try to get them posted as soon as I can.
I've seen color charts that assign very exact temperatures to the colors of steel, but I assume they are all for simple carbon tool steels. I know other steels have different temps, but I'm not familiar with them.
Especially now with all the new powdered steels, the applicable temperatures are quite a lot higher.
Of great importance to me are tempering colors, because I do need to know how hot a blade can get before it starts tempering and losing hardness while grinding.
I *think* tempering colors are only significant with hardened steel, and really have no relevance when grinding steel before hardening.
Your scientific explanations are always incredible! That's like making science come alive. You're a great teacher!
Most of what I know relates to hardening and tempering of tool steel. The colors are supposed to be very accurate. You just need to know what color you're looking for. That's were it gets subjective, but experience will allow your eye to be very accurate.
For anyone heating steel in anything other than a knife kiln, there is one thing that is critical. It's actually so critical, that it's called "Critical". It's the austinization temperature, or the temperature you're looking for when you're trying to harden or normalize steel. Surprisingly, that color becomes easily recognizable.
I differentially harden most of my blades by heating the edge with an A/O torch, and a large welding tip. I have a a couple relevant videos that a friend took not long ago. One is of hardening the edge, and another shows how I draw the spine to spring steel. I'll have to try find to post them.
I just got a new laptop recently, and I didn't want to lose any information from the two cheap laptops it is replacing. I noticed I have way more pictures than I thought I did, so I'm trying to get them coordinated. I will try to get them posted as soon as I can.
I've seen color charts that assign very exact temperatures to the colors of steel, but I assume they are all for simple carbon tool steels. I know other steels have different temps, but I'm not familiar with them.
Especially now with all the new powdered steels, the applicable temperatures are quite a lot higher.
Of great importance to me are tempering colors, because I do need to know how hot a blade can get before it starts tempering and losing hardness while grinding.
I *think* tempering colors are only significant with hardened steel, and really have no relevance when grinding steel before hardening.