ASTM A 790

ASTM A790 covers seamless and straight-seam welded ferritic and austenitic steel pipe intended for general corrosion service with particular emphasis to stress corrosion cracking. These steels may be susceptible to embrittlement if exposed to prolonged elevated temperatures.

Both ferritic and austenitic stainless steels are not hardenable by heat treatment. Austenitic can only be hardened by cold-working and ferritic is not hardenable by either either heat or cold-working.

Standard austenitic grades are AISI 201-348 and Ferritic are 405, 430, 430F, 430FSe and 446. Suppliers, such as Carpenter, also offer variations of these grades.

Regardless, it's a matter of choosing the appropriate grade by availability, application, environment and price.