Good morning everybody this is Michael with Michlin Metals. Can anyone guess what we’re talking about today? More Nickel Alloys! This is Part 2 on Nickel Alloys but before we get into it, let’s just take a second and subscribe. Hit that little button, right here. There’s only about 8% of you watching who have subscribed maybe less….so the other 92% of you, click that button. Ok, let’s get into the Nickel Alloys

In our second part we are going to talk about the family of three alloys of  nickel and copper which are Monel 400Monel R-405Monel K-500……. compositions are roughly two thirds Nickel and one third Copper……. These elements form a solid solution with each other.. a stable mixture that cannot be made stronger by heat treatment.  It takes certain additional elements to make an alloy strengthened by heat treatment.

These three alloys are named  Monel 400, Monel R- 405 and Monel K-500 when produced by Special Metals Corporation.  Generic versions cannot carry the “Monel” name.

Monel 400 or Alloy 400  contains a minimum of 63% Nickel (plus Cobalt), point 3% maximum Carbon, 2.0 % maximum Manganese, 2.5% maximum Iron, point 5% maximum Silicon, point 024% maximum Sulfur, and 28 to 34% Copper.

As we noted in our first of this series, Cobalt is considered as part of the Nickel requirement. Nickel and cobalt are typically found together in the ore they are produced from. Separating the two to very high levels of purity increases the cost. Metallurgically very similar we often see ” Nickel (plus cobalt)” considered as one element when it would not affect the performance of the alloy.

This  “solid solution” alloy is not hardenable by heat treatment.  It can be strengthened by cold work.

Depending on the specific composition of the material, it can be either magnetic or non-magnetic at  near room temperatures …. 70 to 120 degrees F  The temperature that this change in magnetic properties occurs is called the “Curie Temperature” .  Magnetic below the Curie temperature and non-magnetic above  If consistent magnetic response is an issue in an application, other alloys are likely better suited for use.

Typical applications for this family of alloys are in marine environments and chemical, and petrochemical processing equipment. Components of valves, fasteners, shafting, piping, and heat exchangers are common.

Monel R-405 has the same basic chemistry as 400 but requires added sulfur to improve its machining characteristics  Sulfur range is point 025 to point 060 percent.

Like 400, it is not hardenable by heat treatment.    It is used mainly for screw machine stock applications.Other applications are not recommended.

Monel K-500 is a higher strength alloy achieved by precipitation hardening heat treatment.  Adding 2.3 to 3.5% Aluminum and point 35 to  point 85 % Ti  to the basic composition creates an alloy that can be heat treated to precipitate these elements and increase its strength.

Solution annealing typically occurs  at  1800 to 1900 degrees F followed by aging at 1100 to 1125 F for hot worked products.  Cold worked material achieves the highest strengths and is typically aged at 980 to 1000 degrees F.

The chemistry of K-500 also lowers the Curie temperature to well below minus 100 F and is reliably non magnetic at higher temperatures

This alloy is used where its higher strength or the magnetic properties are useful

Specifications for these alloys are in the B series of ASTM standards, SB for Boiler and Pressure Vessel applications,  AMS for Aerospace, and Nace for petrochemical use. Specifications include the product form (bar, tube, plate etc) along with  the processing requirements for that application.  So check the specs and then check them again.

Thank you for tuning in and watching. If you made it this far and haven’t subscribed, you should just do it! Click right here, help me out. If you want to catch up on any of the previous videos, click here. Thanks again for watching and have a great day, this is Michael with Michlin Metals. Out.