Hydrogen Embrittlement of Music Wire 2

[swall]

Does anyone know of a case where a music wire spring failed due to hydrogen embrittlement?

 

[btrueblood]

Not if it wasn't plated, or immersed in warm H2...

 

[EdStainless]

Even some acid cleaning operations will cause it. And of course if there is any active corrosion you can get Hydrogen.
Springs are always baked out after forming.

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Plymouth Tube

 

[swall]

My reason for asking, Ed, is that music wire is not a martensitic structure, it is patented (fine pearlitic structure).

 

[TVP]

swall,

Pearlitic microstructures are not immune to the effects of hydrogen. They are more resistant to brittle fracture than martensitic microstructures, but they are affected, usually by hydrogen-enhanced decohesion/delamination of the pearlite lamellae. There are a number of good references on the subject, such as the following:

Microstructural aspects upon hydrogen environment embrittlement of various bcc steels

http://www.sciencedirect.com/science/article/pii/S0360319909016905

Microstructural aspects upon hydrogen environment embrittlement of various bcc steels

http://www.springerlink.com/content/l6085880468784m8/

Hydrogen assisted cracking in progressively drawn pearlitic steel

http://www.sciencedirect.com/science/article/pii/S0010938X07000741

Microstructure-based modeling of hydrogen assisted cracking in pearlitic steels

http://www.sciencedirect.com/science/article/pii/S0921509301010371

Evaluation Method for Delayed Fracture Susceptibility of Steels and Development of High Tensile Strength Steels with High Delayed Fracture Resistance

http://www.nsc.co.jp/en/tech/report/pdf/8011.pdf

 

[swall]

Thanks, TVP. That will keep me occupied for a while.