10-10-2018, 11:34 AM
Thanks to all! Please Larrin, "I think you made it up " don't be so brutally honest. A little literary license is acceptable from time to time. We considered "distemper" but found that it can be vaccinated against. In addition to KG's reference we also found ourselves in good company with everyone's favorite electric knife sharpener and we quote "Chef’s Choice recommends using a multi-stage sharpener-whether electric or manual-with guides (to ensure angle control) and diamond abrasives (which will sharpen any metal alloy and never overheat/detemper the blade)." Having put forth our defenses, we agree and prefer "overheat" as well.
Mark, thanks much for your support and we have yet to research "Tempilac" but that is exactly the kind of help we are looking for here. We just ran across the Omega product and it looked as if it might work so advanced it as a possibility. If something else might work better we'd love to hear about it.
Which brings us to Geno. Thank you very much for the link to the Dr.'s paper. Very useful and informative indeed. We have a lot of "lookers" on many of the Exchange's studies but not so many contributors so your input was much appreciated. I had a couple of takeaways from the Dr.'s paper and please correct us if we've missed or gotten something wrong here. It would seem that this is primarily a study of how much heat (as it relates to grinding steel), at how long a time, various steels begin to lose some of their hardness. We did find it interesting that he didn't seem to think that color changes in the steel were a good indicator of this loss of hardness but my translation wasn't good to enough to understand why he feels that way. Here's a couple of highlights for everyone here;
Applying his general formula and at at 300F (150 C) of a knife beginning harder than HRC62 it would might look something like this for a particular steel, Hardness reduction vs. time @ 300F
62 HRC 23 minutes
61 HRC 21 hours
60 HRC 3 days
59 HRC 6 months
58 HRC 16 years
He references 600C (1100F) several times as some sort milestone temperature and we're not certain why other than we suppose that most of the hardness might be removed from the steel at that temperature if it were held at that temperature for a long enough time. He gives an example where a particular steel, when heated to 600C, was reduced in hardness from HRC56 to HRC48 in 36 seconds. Someone with better German translation skills than our own might be able to glean more and more accurate information from this study than we did.
KG. What is the reason for your suggested use of a metallurgical microscope? We would be only trying to discern color changes in the lacquer ,as we understand the process, and it would seem that an optical scope would suffice.
Mark, thanks much for your support and we have yet to research "Tempilac" but that is exactly the kind of help we are looking for here. We just ran across the Omega product and it looked as if it might work so advanced it as a possibility. If something else might work better we'd love to hear about it.
Which brings us to Geno. Thank you very much for the link to the Dr.'s paper. Very useful and informative indeed. We have a lot of "lookers" on many of the Exchange's studies but not so many contributors so your input was much appreciated. I had a couple of takeaways from the Dr.'s paper and please correct us if we've missed or gotten something wrong here. It would seem that this is primarily a study of how much heat (as it relates to grinding steel), at how long a time, various steels begin to lose some of their hardness. We did find it interesting that he didn't seem to think that color changes in the steel were a good indicator of this loss of hardness but my translation wasn't good to enough to understand why he feels that way. Here's a couple of highlights for everyone here;
Applying his general formula and at at 300F (150 C) of a knife beginning harder than HRC62 it would might look something like this for a particular steel, Hardness reduction vs. time @ 300F
62 HRC 23 minutes
61 HRC 21 hours
60 HRC 3 days
59 HRC 6 months
58 HRC 16 years
He references 600C (1100F) several times as some sort milestone temperature and we're not certain why other than we suppose that most of the hardness might be removed from the steel at that temperature if it were held at that temperature for a long enough time. He gives an example where a particular steel, when heated to 600C, was reduced in hardness from HRC56 to HRC48 in 36 seconds. Someone with better German translation skills than our own might be able to glean more and more accurate information from this study than we did.
KG. What is the reason for your suggested use of a metallurgical microscope? We would be only trying to discern color changes in the lacquer ,as we understand the process, and it would seem that an optical scope would suffice.