What is 904L stainless steel equivalent to?

What is 904L stainless steel equivalent to?

 

904L (UNS N08904, 1.4539) is a high alloy austenitic stainless steel. Its approximate composition of 20% Cr, 25% Ni, 4.0% Mo and 1.5% Cu ensures a Pitting Resistance Equivalent Number (PREN) of approximately 43. It was developed for sulfuric acid service with major concentrations ranging from 20% to 85%.

904L's corrosion resistance is equivalent to most super duplex stainless steels (SDSS) in a wide range of applications.

As an austenitic stainless steel, 904L has a wider service temperature range and can be confidently specified for applications <-50 degrees Celsius or >250 degrees Celsius where SDSS are restricted. At cryogenic temperatures, 904L maintains good impact toughness and does not form deleterious intermetallic phases at higher temperatures. However, the higher strength of super duplex stainless steels means that thinner sections can be used to achieve the same structural performance. 904L has a higher alloy content, which makes it inherently more expensive than SDSS, even before considering the strength difference. In summary, the comparison of 904L stainless steel to duplex stainless steel is interesting. Super duplex steel is the better choice for most projects, with lower cost and higher strength.

Chemical Analysis

Weight % (all values are maximum unless a range is otherwise indicated)

Nickel	23.0 min.-28.0 max.	Silicon	1.00
Chromium	19.0 min.-23.0 max.	Phosphorus	0.045
Molybdenum	4.0 min.-5.0 max.	Sulfur	0.035
Copper	1.0-2.0 max.	Iron	Balance
Manganese	2.00