Ferritic Stainless Steels—Allegheny Ludlum

TABLE 4.3 FERRITIC STAINLESS STEELS-ALLEGHENY LUDLUM 

AL 29-4C is d f srritic stainless steel developed specifically for power plant surface condenser tubing. AL29-4C has excellent resistance to brackish, polluted or high chloride waters, e.g., seawater. Consistent with its composition, AL 29-4C performs similar to austenitic stainless steels in a variety of other environments. Of particular importance is the excellent resistance of AL 29-4C to condenser environments where ammonia, other noncondensables and sulfides attack copper base alloys. 

The ferritic structure and the low level of copper and nickel make AL 29-4C highly resistant to chloride stress corrosion cracking. Laboratory tests of annealed strip have shown no evidence of stress corrosion craoking in U-bent samples after 500 hours in boiling 26% sodium chloride. 

Intergranular Corrosion Resistance AL 29-4C contains a deliberate titanium addition to stabilize the carbon and nitrogen. AL 29-4C is resistant to intergranular corrosion as determined by the copper-copper sulfate-sulfuric acid tests detailed in ASTM Specification A 763, Practices Y and Z. 

Source M. A. SIreicher, Slainless Steels Past. Present and Future , 

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TABLE 4.3 FERRITIC STAINLESS STEELS-ALLEGHENY LUDLUM (continued)... 

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