Martinsite 1

[jreau]

I need help solving an issue. I work for a company that makes springs and we had one fail prematurely and the sample was sent to the wire manufacture for analysis. They said it contained martensite from our process and that was the cause of the break. In my 36 years here it has never been the wire mills fault, always ours. well this time I want to pursue it further to learn more about this. Let me explain our process. This spring was made on a machine similar to a lathe where the wire goes through a pipe and is wrapped around a mandrel at a speed of about 150/min. They are saying the pipe caused enough friction to reach the temperatures needed and room temperature cooled the wire after reaching those temperatures and that created the martensite state. I have done some reading on what it takes to create martensite and I can't see where we did that.
Any help would be appreciated.

thank you
Jeff

 

[metengr]

You need to have a proper failure analysis performed by an independent metallurgical testing lab to determine if fresh martensite is really being produced. I would present the independent lab results to the supplier versus relying on the supplier for the analysis.

 

[EdStainless]

And it would help to know some more details, such as the material.
You would need to provide a sample of the wire (from the correct lot) and the failed spring. WE used to retain wire samples just in case.

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P.E. Metallurgy, Plymouth Tube

 

[Maui]

Ask the mill to provide you with a material certification that lists the grade of steel, its chemical composition, grain size, hardness, condition in which it was ordered, etc. Let us know what they tell you.

Maui