CRONIDUR Information ? 2

[Fred]

I search informations on cronidur alloy : approximative chemical analysis or equivalent alloys, advantages and drowbacks,....

Thanks

 

[kenvlach]

I found several 'Cronodur' alloys. The one with many current references is Cronodur® 30.

"Cronidur® 30 is a martensitic throughhardened steel that can also be induction case hardened. The primary difference between 52100 and Cronidur® 30, for example, is that in Cronidur® 30 some of the carbon content has been replaced with nitrogen. A comparison of the chemical compositions of Cronidur® 30, 52100 and 440C are presented in Figure 2."

Material C N Si Cr
52100 1.00 — 0.25 1.45
Cronidur®30 0.31 0.38 0.55 15.2
440C 1.08 — 0.40 17.0

Some mechanical properties:
52100 Cronidur® 30
Hardness 58 HRC 58 HRC
Useful Operating T 250°F 390°F
Bending Strength 120 ksi 160 ksi
Fracture Elongation:
• Length 1 3
• Transversal 0.3 2

Claims for Cronidur® 30 include a higher fatigue life and finer microstructure (evidence is shown) and greater resistant to corrosion than 440C (conditions not stated). See the bulletin at

http://www.bardenbearings.com/PDF CD/PB18.PDF

It seems to have been used primarily in aerospace, but also in Swiss watches, medical devices, etc.

 

[Fred]

Thank you for your quick answer. It is very useful and confirm our assumption that CRONIDUR is not so different from a Aubert&Duval alloy : XD15NW (X40CrMoVN16.2.