Bending Nitronic 60 2

[tc7]

Is anyone familiar with bending of Nitronic 60?
For 0.25" diameter bar stock, I would like to bend in a type of hairpin configuration, but do not know what minimum radius I can expect? We don't have shop access for trial and error, so any experience, advice, calulations, rule of thumb welcomed.
Info I have on Nitronic 60 is as follows:
(Annealed State)
UTS 103 KSI
.2% YS 60 KSI
Hardness Rb95



Thanks.
TC

 

[metengr]

I would estimate that based on the forming characteristics of annealed Nitronic 60 and the thickness you mention, that you could make a hairpin bend around a 4T bend radius with no problems. The value I mentioned is rather arbitrary for your application, but is better than nothing and is consistent with a standard bend test in accordance with ASME Section IX. Typically, a 4T bend radius would inflict about 20% elongation on the outer fibers of the bend.

 

[metengr]

As a side note, while I was looking for some background information on Nitronic 60, I found this site below that has a rather detailed product brochure with galling test data, applications and mechanical property data devoted to Nitronic 60. Go to the web site below, click on Nitronic 60 and click on Full Brochure. It is an 11MB file.

http://www.hpalloy.com/DataSheets/index.html

 

[Cockroach]

Heat it up, cherry red and bend it as required around a couple of posts of desired radius. I like the quench/temper technique in oil, something like motor oil 10W40 or so. This can be done in the shop, I do it all the time.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[arto]

The good old Armco bulletin is on the Italian AK steel website:

http://www.aksteel.it/cataloghi/download/nit60-1.pdf

 

[tc7]

Mr. Hueston-
Are you suggesting that if I heat it up I can expect to get a bend radius very much less than 4T? I'm not sure how "ductility" is quantified on this alloy but do you think a 180 degree bend of radius 1/2T (or less!!)would be unreasonable with heating? Remember, I don't have a shop that can play around with this for me.
Thankyou for your interest.
TC

 

[metengr]

tc7;
Better be careful here because the quench and temper that Mr Hueston mentions above is reserved for alloy steels, not Nitronic 60 material. Nitronic 60 behaves like a 3XX series austenitic stainless steel. Heat can be used to assist the bending operation. However, you can significantly alter the corrosion resistance of this material if it is not performed properly. A 4T bend is rather generous and can be safely done using annealed material.

 

[boo1]

We have cold formed it sucessfully, we did find out the spring back was more than expected.

 

[tc7]

boo1-
What exactly did you do in your cold forming? how tight of radius did you go for and in what thickness of mat'l? What amount of springback? did you work out a computation for the springback or other K-factor's? What do you think of Ken's idea of hot forming a tight radius of 1/2T? Your experience would be of interest.
Thanks.
TC

 

[boo1]

We were using 1/8" thick 2 inch angle cold formed to a 24" radius. We just incresed the bend by trial and error. I cant respond to hot forming.

 

[Cockroach]

TC7 and MetEngr:

I've simply provided you with a direction to follow, one that can be done very simply in one's garage, since you don't have a shop.

As far as temperatures, ductility of the metal, etc, you need to dive into the problem and solve that for yourself.

Remember, this forum brainstorm ideas or inquires upon information that others may have knowledge upon. As a professional, I trust that many users here get an idea, then develop it accordingly. The concept of due diligence comes to mind.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada