Hardenable and Corrosion Resistant
Hardenable and Corrosion Resistant
(OP)
What would be a good material that is hardenable by heat treatment (up to 40 to +50C), corrosion resistant, and can handle subzero temps. down to -50°F (-46°C). I was looking at 440C SS but am concerned with the low temps. and becoming brittle. Is 440C rather ductile at -50°F?
How about a nickle based alloy?
Thank you
How about a nickle based alloy?
Thank you





RE: Hardenable and Corrosion Resistant
"Martensitic stainless steels are optimised for high hardness, and other properties are to some degree compromised. Fabrication must be by methods that allow for poor weldability and usually also allow for a final harden and temper heat treatment. Corrosion resistance is lower than the common austenitic grades, and their useful operating temperature range is limited by their loss of ductility at sub-zero temperatures and loss of strength by over-tempering at elevated temperatures."
---http://www.azom.com/details.asp?ArticleID=1024
Also, the corrosion resistance of 440C is so poor in the hardened condition that it really isn't a stainless steel:
440C contains 0.95-1.20 wt% C and 16-18 wt% Cr. Hardened, most of the Cr is in the form of the carbide Cr23C6. One gram atom C can tie-up 3.8333 gram atoms Cr, so 1 wt% C can tie-up 16.6 wt% Cr, leaving a non-stainless metal matrix.
RE: Hardenable and Corrosion Resistant
RE: Hardenable and Corrosion Resistant
We have use both of these materials at LN2 temperatures with no problems.
If possible comeback with you specific application to obtain a little more information.
RE: Hardenable and Corrosion Resistant
RE: Hardenable and Corrosion Resistant
Is it for an aerospace/military use?
http://www.webspawner.com/users/israelkk/
RE: Hardenable and Corrosion Resistant
RE: Hardenable and Corrosion Resistant
RE: Hardenable and Corrosion Resistant
RE: Hardenable and Corrosion Resistant
RE: Hardenable and Corrosion Resistant
Nickel alloys will not be any better than 17-7 PH stainless steel in terms of surface hardness. No matter what the material is, a spring needs to be properly designed for the operating environment, stresses, etc., and therefore most spring materials have a surface hardness of 55 HRC or less, because above this they do not possess sufficient fracture toughness to be resistant to stress concentrations, surface defects, etc.
Spring steels that have high carbon contents (> 0.50%) and have been quenched and tempered to a martensitic microstructure will possess the best surface characteristics in terms of wear resistance. ASTM A 401 and ASTM A 877 define the requirements for Cr-Si steel spring wire (essentially SAE 9254), with the Valve Quality material having fewer allowable surface defects, decarburization, and non-metallic inclusions. If the spring requires a wire diameter greater than 18 mm, then you may need to consider a bar that can coiled and then heat treated, instead of purchasing wire that is already quenched and tempered.
RE: Hardenable and Corrosion Resistant
If you want higher then MP35N or Elgilloy may be your only options.
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Corrosion, every where, all the time.
Manage it or it will manage you.
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Hardenable and Corrosion Resistant