| Allegheny Ludlum Types 201 and 201L have the greatest tonnage of the Cr-Ni-Mn steels (200 series). Type 201L provides advantages over the 18-8 grades in certain applications. Lower cost manganese and nitrogen additions are partial substitutes for nickel making them more economical alloys. Because they possess a very desirable combination of economy plus good mechanical properties and corrosion resistance properties, they have been used in a wide variety of consumer and transportation applications. Balancing of alloying elements (austenitizers versus feritizer) in Type 201L produces an austenitic structure in the annealed condition even at subzero temperatures. This austenitic structure achieves significant strengthening through cold working of the material to produce the transformation to a stronger martensitic structure. Type 201L is a low carbon version of Type 201 and maintains satisfactory intergranular corrosion resistance in applications involving welding particularly heavier gage material. Typical applications for Types 201 and 201L are cookware bodies/lids, hose clamps, piston rings, transit car structural member, transit car roofing/siding, thermal window spacers, air bag containers, and truck trailer posts and door frames. Information provided by Allegheny Ludlum Corporation. |
