Emission colors are independent of material. These are described by the Planck black body radiation equation (1900).
Temper colors vary with material and with surface conditions. Stainless steels, being more resistant to oxidation, need to get hotter to show the same colors shown by low alloy steels at lower temperatures. Different stainless steels will show slightly different temper colors at the same temperatures. Surface contamination (hand prints, residual cleaning agents, etc.) and atmosphere will affect temper colors.
-John Grubb - Sent from my iPhone
Original Message:
Sent: 2/12/2025 10:03:00 AM
From: John Tartaglia
Subject: RE: Heat color chart for 304 stainless
All,
The article "Temper Colors for Steels" in ASM Handbook, Vol. 4D, "Heat Treating of Irons and Steels,", J. Dossett and G.E. Totten, editors, pages 550 and 551 addresses this subject in Figure 1 for plain carbon steels.
Sincerely,
John Tartaglia
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John Tartaglia
Senior Metallurgical Engineer
Element Materials Technology Wixom Inc
Novi MI
(248) 207-0893
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Original Message:
Sent: 02-11-2025 11:31
From: Robert Utter
Subject: Heat color chart for 304 stainless
Thanks for your consideration. Lacking a thermal camera, we're trying to give an approximate temperature range that the 304 stainless reached as a sample cup over a propane flame. We have pictures of the emission color. We'd like a technical reference that we can point to and say "orange" indicates this ....
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Robert Utter
Research Faculty
UNIVERSITY OF MARYLAND
HYATTSVILLE MD
(301) 439-0436
Original Message:
Sent: 02-11-2025 08:36
From: James Quinn
Subject: Heat color chart for 304 stainless
Rob -
Are you looking for post temper or at temperature?
regards,
- Jim
Original Message:
Sent: 2/10/2025 1:11:00 PM
From: Robert Utter
Subject: Heat color chart for 304 stainless
Greetings,
There is a multitude of color charts on the web for the emission colors of steels as a function of temperature.
We're looking for a reference that we can use in a journal paper.
Thanks for your attention.
Bob
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Robert Utter
Research Faculty
UNIVERSITY OF MARYLAND
HYATTSVILLE MD
(301) 439-0436
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