SS304 and SS304L - Corrosion Resistance

What if it turns out that 304 or 304L is not the best material? Maybe 316, 316L, Monel, Inconel, Incolloy, Hastelloy, or titanium might be better. Rather than go into this with a prior agenda, check a few corrosion resistance sources such as MatWeb.

See these links:

http://www.aksteel.com/pdf/markets_products/stainless/austenitic/304_304L_Data_Bulletin.pdf

http://www.azom.com/details.asp?articleid=965

http://www.upmet.com/media/302-304-304l-305.pdf

http://www.outokumpu.com/35046.epibrw

http://metals.lincdigital.com.au/files/Product%20datasheets/Atlas304-304L.pdf

- MS

SS304L has low carbon and good for chemical resistance over SS304. Specific to corrosion resistance criteria SS316 had better property over SS304.

For extreme corrosion problem due to chemical service, sea water service etc. Titanium is best material but very costly.

An evaluation to be done while selecting material and considering service life Vs. costing.

For the galvanic (corrosion) character of dissimilar metals (in saltwater) one could do worse that to see:

http://www.engineersedge.com/engineering/imagefiles/5169.pdf

It is MIL-STD-889B "Dissimilar Metals."

Other environments would have similar but different results. It makes a reasonable guide.

You might consider the possibility that 304/304L is not the most corrosion-resistant stainless, and certainly not the most corrosion resistant metal.

"Optimum characteristics" in terms of corrosion resistance is relative to the environments, operating conditions, type of service ... so you'll have to define all these factors and then you can assess if 304 is the optimum ... I mean 304 could be okay for a pipe but if you are close to the sea it's not the best choice.

S

Dear Sir,

You can better use Inconel 625 or Hastelloy Pipes for the above application.

The difference between SS 304 & SS 304L is only in the chemical composition of Carbon. SS 304L has lesser % of carbon & will perform slightly better than SS 304.

Fusion