This sounds like an opportunity to "do it yourself". Send a collection of relevant parts to a lab and have both tests done.
I used conversion tables extensively and learned that they have their limitations. What are the error bands and uncertainties? Very few conversion charts have this information available, even if the originators did a good job of collecting it.
How well were the machines calibrated? Manual or automatic application? Then you get into the materials issues: has any cold work been done? How does the hardness vary with depth of cold work? (Substantially for austentics.) Is the test being done on a cross section or an original surface? What surface prep was involved, a metallographic finish for the microhardness versus as-rolled or rough ground for Rockwell?
If you commission your own test you can control all of this, though you may be dismayed at the variability of the real world compared to a nice single value in a handbook conversion table. However the cost of getting it wrong may exceed the cost of testing. Establishing a correlation within a limited range of hardnesses and product forms may pay off for you, or you may learn that the conversion value should not be relied upon.
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Paul Tibbals
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Original Message:
Sent: 11-07-2021 19:46
From: Lawrence Cheung
Subject: Hardness conversion for austenitic stainless steels
Yes, thank you, but I was looking at a way to convert microhardness to Rockwell hardness.
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Original Message:
Sent: 11/7/2021 3:07:00 PM
From: John Grubb
Subject: RE: Hardness conversion for austenitic stainless steels
E140, Table 6 is intended for austenitic stainless steels.
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John Grubb
New Kensington PA
(724) 448-5272
Original Message:
Sent: 11-07-2021 12:05
From: Lawrence Cheung
Subject: Hardness conversion for austenitic stainless steels
Sorry, forgot to say ASTM E140
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Lawrence Cheung
Sr. Principal Metallurgist
Northrop Grumman
Original Message:
Sent: 11-06-2021 16:39
From: Lawrence Cheung
Subject: Hardness conversion for austenitic stainless steels
Would table 3 be appropriate for conversion of austenitic stainless steel hardness conversion?
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