Trouble Heat Treating Baker Forge Bronze SanMai

CDHumiston

Well-Known Member
I bought a very expensive piece of Bronze SanMai from Baker Forge. It is made with bronze and 80CRV2. I followed their heat treat instructions to the "T" and I am unable to get it past 50 HRC. I have Paragon Knife Kiln that is very stable. I also have an oil heater for my quench oil with a temp control. I am using Parks AAA as recommended. I tempered the blade at 320 for two 2 hour cycles.

I have made sure to remove all the scale from the blade and I'm testing a nice clean spot. I've tried to avoid setting the diamond on my Rockwell tester on anything that looks like bronze.

Here are their instructions...any ideas? I emailed them and they said I should be able to get 58-59 HRC with no problems.

For Billets with 80crv2 Cores:
  • Normalize at 1600F, 1500F, and 1400F letting cool to black between each cycle.
  • Heat to 1550 F
  • Hold for approx 10 mins for "knife blade thickness"
  • Quench in warm quench oil (not Canola) 86 F-122F
  • Temper immediately for 2 hours, cool in water and temper for another 2 hours
 
"I have made sure to remove all the scale from the blade and I'm testing a nice clean spot. I've tried to avoid setting the diamond on my Rockwell tester on anything that looks like bronze."

Do you have a test piece to check calibration on your rockwell tester?? That is all I got for a suggestion.
 
"I have made sure to remove all the scale from the blade and I'm testing a nice clean spot. I've tried to avoid setting the diamond on my Rockwell tester on anything that looks like bronze."

Do you have a test piece to check calibration on your rockwell tester?? That is all I got for a suggestion.

I have 2 calibrated test discs. I have checked with both and they are within .2 so it's not that. I guess I'll have to call Baker Forge again...
 
What is the outer layer steel? Many times the outer layer won't test for Rc very good since it can be a low carbon alloy, or non-hardening SS. Looks like you'd need to test the core portion only, but that's sorta hard to do since both sides need to be parallel. Have you asked the vendor if Rc testing should work?
 
Yeah, you have to test only the core 80crv2. It has to be a spot that is solid steel all the way through, so it has to be near your edge. If there is a layer of bronze or copper below the test point it will give you a softer reading.
 
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