Nitronic -60 / Galling 2

[Pucp]

Hi, I work in a pump company, and a purchaser have ask us about a part of a pump (nuts) made of Nitronic-60 (I have never heard about it), we only work with steels, stainless steels, and foundries, also with bronze, brass so I will appreciate if anyone can tell me where I can find the best information about Nitronic-60, and how can I purchase it (very important), because I live in South America - Peru, also if someone can explain me what is galling, its mechanism of attack, what materials mostly affect and why Nitronic-60 is recommended in this case. I have read that is very common in nuts, and shafts. Thanks in advance

 

[jcrowe]

The Nitronic series are stainless steels, the most common we use is Nitronic 50 (UNS S20910) which is Chromium-Nickel-Manganese-Molybdenum alloy. Most steel distrubutors in the U.S. know what it is and it's carried in stock as a Stainless Steel Specialty or Super Alloy. Check with your largest local? steel distributor for purchase information. If you don't have any luck that way let me know and I'll check my suppliers to see if anyone knows who stocks it in your part of the world. Galling is a form of friction welding which occurs when surfaces are rubbed together, the worst cases occur when trying to use aluminum hardware though all the stainless steels have the same problem. We avoid the galling problem by using anti-seize compounds on threaded surfaces when assembling. The Nitronics are strong, tough and very corrosion resistant. I use the Nitronics in a marine environment for threaded fasteners. Primarily nuts, bolts and pump shafts. Hope this helps! JSC johnscrowe@worldnet.att.net

 

[jimdempster]

Helicoil makes and stocks Nitronic helicoils. If you could modify your parts to accept the Heilcoil, you get the following benefits:
-The helicoil only costs a few dollars each
-The helicoil is replaceable in case of galling
-It can be mailed from the US or Canada economically to you by mail, since the parts are small and don't weigh much.

While Nitronic provides the best resistance to galling, the ordinary grade of stainless helicoils work well too because the helicoil wire is severely cold-worked when it is made. The cold-worked metal inherently resists galling.

If you examine the Nitronic stainless series composition, you will see that the Nickel content is always lower and the Manganese content is always higher; this combination resists galling with only a small decrease in corrosion resistance.

Check out the website at

http://www.emhart.com.

Emhart Fastening Technologies/Helicoil is located in Shelton, CT USA; Irvine, CA USA; and Quebec, Canada.

Ask for Technical Bulletin 898-1 for a comparison of Galling Resistant Inserts. One thing missing is the combination of stainless screws and the non-Nitronic stainless Helicoil inserts. Both Nitronic and non-Nitronic inserts work well, but the report only covers Nitronic inserts.

 

We have a problem here in our safety valve manufacturing, wherein, we use a nitronic sleeve guide and a stainless steel 316 component which sort of reciprocates in the nitronic guide, wear of the ss material takes place and particles get embedded in the nitronic naterial.

 

[boo1]

Consider a hard surface coating of Tungstin Carbide (HFOV applied) to the 316 material.

 

[TVP]

You may also want to consider a different grade than 316 for the reciprocating component. There are stronger, more wear resistant stainless steels that still have good corrosion resistance. Depending on the environment, hard chrome plating may be a suitable alternative to HVOF-type coatings, although they have some definite limitations. I can make some suggestions on other alloys to consider if you are interested.

 

[metman]

What is HFOV or is it HVOF? Am guessing an acronym for the process of applying the TC.

Another material choice, again depending upon the environment might be Nitrided (D2) Type 430 Tool Steel or Nitrided (H13) Type 521 or a Nitriding grade Steel since Nitriding provides fair corrosion Resistance in some environments. Jesus is the WAY

 

[GRoberts]

HVOF sands for High Velocity Oxy-Fuel. It is a process for appling coatings by which a powdered substance, often metal, is melted and sprayed onto a substrate to which it is supposed to metallurgically and/or mechanically bond. The bond for this type of spraying is supposed to be stronger than conventionial low velocity spraying, and also produces a denser coating.

GRoberts