Alternatives for corrosion resistant alloys to Hastelloy 7

[LuisLazcano]

Hi guys,

Looking for an alternative material to Hastelloy C-273, in a medical device heat exchanger, where it will be exposed to heavy use of bleach (that eliminates stainless steels as possible option), so corrosion resistance is the top priority; but also cost and low density for the medical device weight.

Do you know of an equivalent alloy to C-273, cheaper and resistant to chlorine corrosion?

I appreciate any suggestion you can give me.

 

[Walyo]

You probably mean Hastelloy C276. Other candidates are the other C-series Hastelloys (C-22 and C-2000), as well as Inconel 686. All these alloys have similar composition (largely Ni, Cr, and Mo) and properties. A version of Inconel with even more Nickel (greater than 70 %) is Alloy 600. Monel 400 contains about as much Nickel as C276, but with appreciable amounts of Copper (32%) and can be more suitable for some applications. There's also commercially pure Titanium, which often competes with the above alloys in corrosion applications. I'm not sure about currently, but I wouldn't expect large variations in price and availability with regard to these metals. The Copper-Nickel alloys (70 to 90 % Copper) offer significantly less cost, but also significantly less corrosion resistance in applications that demand the above metals. Additionally, polymers sometimes prove to be a better (cheaper) choice when it comes to corrosion resistance, but I'm assuming you've ruled these out.

Tom

 

[LuisLazcano]

Many thanks for your information Tom.

What are the commercially most common Copper-Nickel alloys (70 to 90 % Copper) that you mention?

 

[EdStainless]

Monel or copper/nickel (either 90/10 or 70/30) are not good options for this service.
The "C" type Ni-Cr-Mo alloys (include alloy 59) are great at pitting and cracking resistance.
Ti is a good option if you are not talking about high temperatures.
You might also consider a superferritic stainless, as these also resist stress corroison cracking.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[JTreglio]

You can also consider zirconium alloys. Zirconium is pretty resistant to corrosion -- more so than titanium. It is also medically acceptable, even more so than titanium.

Jim Treglio
Molecular Metallurgy, Inc.

 

[tomwalz]

Try

Scott Pyle
High Performance Alloys
444 Wilson St.
P.O. Box 40
Tipton, Indiana 46072
800 472-5569


They supply us and we have been very pleased with them.

Tom

 

[LuisLazcano]

Thank you very much, I appreciate all your feedbacks, they have been very helpful to me.


Jim Treglio, do you know of any specific zirconium alloy of low cost and high resistance to chlorine corrosion? I did a search but the variety of zirconium alloys is very big.

Thanks again for your answers.

 

[JTreglio]

Luis,

I can't, but you might want to check with Wah Chang or other zirconium suppliers. They should be able to help you.

Jim Treglio
Molecular Metallurgy, Inc.

 

[ApC2Kp]

To LuisLazcano,
Recommend that you consider AL6XN for equipment subjected to the CIP clean-in-place bleach solutions. Pharmaceutical and food processing equipment and piping fabricators have worked with it for upgrade applications. The polished finishes are also important for complying to requirements of zero crevices for cleaning. Check with some vendors:

http://www.csidesigns.com

(Central States Ind'l Eqt & Service)

http://www.psitanks.com

(Precision Stainless)

http://www.toplineonline.com

(TopLine tubing, valves, pumps)

http://www.alleghenybradford.com

(tanks, pumps, tubing, valves)