Full Transcript:
What’s up guys?!?!?!? This is Michael with Michael Talks Metal back again. Ya miss me? Before we jump in how about the 96 out of 100 of you fine folks who watch hit subscribe? ANY OF YOU? It helps support the channel and if you find the content useful, we’d appreciate it! Let’s jump in.
Todays topic is another of the cobalt base alloys…….. alloy 188. There’s a tradename – Haynes 188, and if you are Haynes, you can make it, if not, you make Alloy 188. So what is alloy 188 or in the UNS numbering system R30188?
Well, its an alloy primarily of Cobalt, Chromium, Nickel, and Tungsten in a solid solution.
A small addition of Lanthanum enhances the protective scale formed at high temperatures.
High strength at temperatures up to 1800 deg F and good oxidation resistance at temperatures up to 2000 deg F are characteristic of this alloy. It has applications in many components of gas turbines.
This alloy is typically annealed at 2150 deg F and water quenched or rapidly air cooled.
Cold worked material can be aged to precipitate carbides that can provide increased strength for some applications.
Chemical composition UNS R30188
Carbon …………………………………………………… 0.05 – 0.15 %
Manganese …………………………………………….. 1.25 % Max
Silicon …………………………………………………… 0.20 – 0.50 %
Chromium ……………………………………………….. 20.0 -24.0 %
Nickel ……………………………………………………… 20.0 – 24.0 %
Tungsten …………………………………………………. 13.0 – 16.0 %
Lanthanum ………………………………………………. .02 – 0.12 %
Boron ……………………………………………………….. 0 .015 % Max
Iron ………………………………………………………….. 3.0 % Max
Cobalt ………………………………………………………. Balance
Density: .330 lbs per cubic inch
Permeability at 200 oersted: 1.0007
Mechanical properties in the annealed condition:
Tensile Strength: 125,000 psi
Yield Strength: 55,000 psi
Elongation: 45 %
Specifications:
Bar
AMS 5772
Sheet, plate, and strip
AMS 5608
AMS specifications contain many additional requirements than just what we have shown you today. Other specifications and part requirements can also apply.
So CHECK the SPECS !!!!!!!
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