305 Stainless Steel - or something like it... 2

[RvL04]

Hi;

I need to have a part machined out of a steel that's close to 305 Stainless Steel. Our supplier tells me 305 is going to be really expensive (it's apparently not that common), but our customer wants something a lot like it. Now, I'm no chemist and don't work with metals a lot at all. Can anyone help me with suggestions; what would be close to 305 S.S.? 302? 304? 316? And while we're at it, what do those numbers mean?

Thanks much, sorry for my ignorance!

Ron

 

[TVP]

Type 305 is a stainless steel that has increased Ni content to lower the work hardening rate. This is most useful in parts that are cold formed/forged. With Ni prices increasing dramatically, you are well advised to consider alternatives. If the part is indeed cold formed, then Type 302Cu (UNS S30430) is the most common alternative. It has 3-4% Cu added to improve cold working. Type 201 or 202 may also be suitable, depending on the need for corrosion resistance, etc. Use the following links for more information:

http://www.techalloy.com/Catalog Pages/Nominal Chemical Composition.pdf

http://www.techalloy.com/News/Exotic materials.pdf

http://www.ssina.com/publications/design.html

http://www.matweb.com

 

[Eltron]

305 stainless steel has a chemical composition of (%):
C (0.12), Cr (17 - 19), Mn (2), Ni (10-13), P (0.045), S (0.03), Si (1). 305 was built up from the basic type with a higher Ni for less work hardening. 304 has a chemical composition of (%): C (0.08), Mn (2), P (0.045), S (0.03), Si (1), Cr (19), Ni (9.25). Unfortunately, without knowing the final application nobody is going to recommend a different material, no matter how close the compositions are. Check out MatWeb for more info.

As far as the alloy designations go here's a (hopefully) brief explanation. Stainless steels are identified in the US by the 3-digit system that originated with AISI. The first digit indicates the classification by composition type. The 200 series has Cr, Ni, and Mn as the primary alloying elements. The 300 series contains Cr-Ni alloys. The 400 series are Cr alloys. Letters that follow the 3-digit number indicate some addition or subtraction to the base alloy. For example, 416Se has Se added for easier machining.

Hope the information is useful.