ASTM A240 ASME SA240 317L /UNS S31703/ W. Nr. 1.4438 stainless steel plate
317L (UNS S31703) is a molybdenum-bearing austenitic stainless steel with greatly increased resistance to chemical attack as compared to the conventional chromium-nickel austenitic stainless steels such as Alloy 304. In addition, Alloy 317L offers higher creep, stress-to-rupture, and tensile strength at elevated temperatures than conventional stainless steels. It is a low carbon or "L" grade which provides resistance to sensitization during welding and other thermal processes.
317L (UNS S31703) is a lowcarbon corrosion resistant austenitic chromium-nickel-molybdenum stainless steel. The high levels of these elements assure the alloy has superior chloride pitting and general corrosion resistance to the conventional 304/304L and 316/316L grades. The alloy provides improved resistance relative to 316L in strongly corrosive environments containing sulfurous media, chlorides, and other halides.
The low carbon content of 317L enables it to be welded without intergranular corrosion resulting from chromium carbide precipitation enabling it to be used in the as-welded condition. With the addition of nitrogen as a strengthening agent, the alloy can be dual certified as 317 (UNS S31700).
317L is non-magnetic in the annealed condition. It cannot be hardened by heat treatment, however the material will harden due to cold working. 317L can be easily welded and processed by standard shop fabrication practices.