What’s up guys?!?!?! This is Michael with Michael Talks Metal back for another stainless session. Today, our video is another of the 300 series of stainless steels found in aerospace applications.
Another way to prevent the formation of Chromium carbides, would be to add an alloying element that more readily forms carbides that would not harm the corrosion resistance.
Type 321 is an austenitic stainless steel that utilizes Titanium’s ability to form stable carbides with any carbon present. It is most often used in the solution annealed condition….. aka Cond A. Typical solution anneal is from 1850 to 2050 deg F. Cooling rate is not critical since the Titanium precludes the formation of Chromium carbides. This also allows 321 to be used at higher temperatures without the formation of grain boundary Chromium carbides that would otherwise make it susceptible to intergranular corrosion.
Is 321 Magnetic? 321 is considered non – magnetic in the annealed condition.
321 SAE 30321 UNS S32100
Density: point 29 lbs per cubic inch
Mean Coefficient of Thermal Expansion from 32 -212 deg F:
9.2 microinch per inch per deg F
Machinability rating: 36 % (of 1212)
Carbon 0.08 % Max
Manganese 2.00 % Max
Silicon 1.00 % Max
Phosphorus 0.04 % Max
Sulfur 0.03 % Max
Chromium 17.00 – 19.00 %
Nickel 9.00 – 12.00 %
Molybdenum 0.75 % Max
Copper 0.75 % Max
Titanium 6 x C Min – 0.70 % Max*
For example: If carbon content is .05 then Titanium minimum is 0.30% (6 x .05)
Typical minimum mechanical properties for 321 in the solution annealed condition:
Yield Strength 30,000 psi
Tensile Strength 75,000 psi
Elongation 35 %
Reduction of Area 50 %
Aerospace specifications for solution annealed condition:
AMS 5570 Seamless Tubing
AMS 5576 Welded Tubing
AMS 5645: Bars, Forgings, Mechanical Tubing and Rings
AMS 5510: Sheet, Strip, and Plate
AMS-QQ-S-763 Bars, Shapes, and Forgings
The ASTM and ASME standards for commercial applications are too numerous to detail here. Refer to our website for more information and videos on stainless steels
Additional specifications and part requirements can alter what we have shown you here today. SO what am I about to say? You know it! CHECK THE SPECS !!!!!!!!!!! Check out the earlier videos on stainless steels here and visit us at our website at www.michlinmetals.com. This is Michael with Michael talks metal, if you are still here and haven’t subscribed click here, if you missed last weeks video, click here. See you guys next Thursday 10am. I’m out.