rod failure

[generalpatton]

OK all you metallurgical wizards....attached are the two mating halves of a rod that failed. One half has scale and the other is clean. The rod broke in transit and travelled under identical environmental conditions in the same carton.

Material is 1045 steel that was nitrided, machined, then salt bath nitrided for the second treatment (QPQ process).

It this possibly a mill issue that was exposed via the nitriding process?

Thanks for your help!

 

[EdStainless]

What about the machining? Looks to be a lot.
Have you checked the properties? case depth?

I would be more suspicious of either improper machining or treatment.

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Plymouth Tube

 

[metengr]

Send it to a metallurgical lab for analysis.

 

[generalpatton]

Yes, we've sent it off....just trying to get a head start on it.

Here's a close-up. Would corrosion appear shiny? I've never viewed it this close.

 

[metengr]

No, corrosion would not appear shiny. You already have some evidence of oxidation (rust) on the fracture surface, and it looks like a brittle fracture appearance. That is about all I can tell.

 

[mrfailure]

The non-corroded shiny areas look like contact damage with the mating surface, which obsfuscates what originally was there. You may see some evidence when this surface is cleaned, but I rather doubt it because of the extensiveness of the damage.