0Cr18Ni12Mo2Ti, TP 316Ti=UNS S31635=1.4571, This is one of the family of 17%Cr12-13%Ni steels containing Mo of 2,0-2,4% stabilized with Ti which minimizes chromium carbide precipitation and improves resistance to intergranular corrosion. In the damp industrial or coastal atmospheres of Europe, they perform better than TP 304/304L and ferritic grades. In low temperature seawater they offer limited resistance to pitting but are susceptible to crevice attack. Their short- and long-time properties at elevated temperatures are also superior to those of comparable TP 304/304L grades.
TP321H=UNS S32100=1.4878
This is the high carbon version of TP 321 which ensures greater creep resistance. Behaves much the same as TP 321 in oxidation resistance. Main applications: Heat exchangers, furnaces, boilers in chemical and petrochemical plant.
TP 321=UNS S32100=1.4541
High carbon steels prone more to intercrystalline attack in weld zones and slower cooling sections. These steel avoids such attacks through its stabilization with Ti. The corrosion behaviour of this alloy in natural environments is very similar to the TP 304/304L alloys. Architecturally, it may not be adequate for near-industrial or onshore locations in Europe. Satisfactory in many low-chloride waters, it is prone to pitting or crevice corrosion in seawater. Water treatment, galvanic protection and deaeration can influence the performance.
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