Growth of Ni-Resist Iron

[MOB1]

A recent example of growth of Ni-Resist type SG iron was experienced. The material was used as a bush and was frozen in liquid nitrogen for installation purposes. Is this just a martensite transformation issue? Any information?

 

[Goahead]

Hi,
are you sure? Ni-resist is described as an austenitic cast iron. Do you find a significant hardness increase?
In any case untempered martensite might be dangerous.

http://www.welding-advisers.com/

 

[MOB1]

I have now carried out a micro structural examination and proved that martensite transforamation is the culprit.
I have recommended freezing and tempering prior to final machining.