Applied research · Cold Facts column #2 · July 2025
The Science of Deep Cryogenic Treatment
This column compares shallow and deep cryogenic treatment and explains the metallurgy behind each, from tool steels to the manganese and white-iron castings used in mining.
By Jack Cahn, Chief Technologist · First published in Cold Facts, Cryogenic Society of America, Vol. 41 No. 3, July 2025
Key points
- Shallow treatment (−60 °F to −190 °F) partly converts retained austenite to martensite and relieves some stress. It costs less and suits moderate-wear uses.
- Deep treatment (−190 °F to −320 °F, liquid nitrogen, a 24–36-hour controlled cycle) goes further: fine eta-carbide precipitation, lower tensile residual stress, induced compressive stress and finer grains for higher strength.
- The benefits are well documented in tool steels (440C, H13, S7, D2, M2), carbon steels (4140, 4340, 1018, 1020) and gear steels (52100, 8620, 1045).
- In manganese steel and high-chrome white iron mining castings, DCT induces deep compressive stress and speeds work hardening through the TRIP/TWIP effect.
- Aluminum and titanium gain mainly stress relief. Copper shows no wear gain but a consistent 1–1.5% permanent increase in conductivity.
- In weldments the heat-affected zone shrinks after treatment; strain at additive-manufactured bond interfaces drops by up to 70%.
This is DCI's summary. The full article, with its figures and references, is in the PDF above.
Related on this site
What deep cryogenic treatment is · Mining wear parts
First published in Cold Facts, the magazine of the Cryogenic Society of America, July 2025. Shared here by the author.
Have a part this applies to?
Tell us the part, the alloy and how it fails. Quotes go out within two business days.