Zirconium in steel 1

[kclim]

Does anyone have information as to the effect of zirconium in steel?

In particular, I'm interested on how it might effect the toughness of a low-alloy steel casting (CrMoV).

From what I can gather, zirconium is used to scavenge nitrogen, and forms 'largish' nitride particles. In tying up the nitrogen, it prevents the formation of aluminium nitride which can be particularly nasty for castings.

However, I'm guessing that an excess amount of zirconium wouldn't be good for the steel. Also, the formation of the large nitride particles - couldn't this also have an adverse effect on the ductility?

Regards

 

[stanislasdz]

Here un good paper :

http://www.jstage.jst.go.jp/article/isijinternational/45/8/1201/_pdf

Hope this help !

 

[stanweld]

In the early 1970's I was involved in developing and testing of Zr treated plate materials to enhance low temperature toughness properties. Zr treated steels demonstrated somewhat superior low temperature toughness compared with Vanadium/Niobium treated low carbon steels, especially when S < 0.005%. One problem that we observed was the tendency of Zr to segregate excessively, without somewhat stringent melting and alloy addition techniques.

 

[steelmtllrgst]

Ferroalloys & Alloying Handbook - Shieldalloy Metallurgical Corp. Always has the basic uses of most alloys - Zr is in there.

We make a Zr grade at our shop - boron treated low alloy NiCrMo grade. Like you said it ties up N preventing AlN from GB formation (theoretically) just like Ti or V.

I have no info on low temp toughness, but that can be affected by TiCN formation, which may mean the Zr is used to scavenge N for this purpose in your case.

 

[metengr]

http://www.shieldalloy.com/contents.html