Stainless steel AISI 317L has as its main characteristic the great addition of molybdenum to its chemical composition, which guarantees an increased resistance to chemical attack when compared with chromium-nicke-molybdenuml austenitic steels of the type AISI 316L. This grade has approximately 1% more chromium, nickel and molybdenum when compared with austenitic steel AISI 316L. Grade AISI 317L offers even better creep deformation characteristics and mechanical resistance to high temperatures when compared with conventional stainless steels. The American denomination “low carbon”, or simply “L”, of grade AISI 317L ensures resistance to sensitization during welding or when thermal processes are applied due to the low carbon in its chemical composition. The combination of molybdenum and nitrogen in the chemical composition of this grade is particularly effective in incresing the resistance to pitting corrosion and crevice, especialy in acid medium with chlorides and sulfur compounds at high temperatures. In addition, nitrogen also contributes to increasing the mechanical strength of the alloy. The main applications of AISI 317L are dedicated to the chemical industry, petroleum and petrochemical industries, industries producing paper and pulp, and as condenseres in power stations using fossile and nuclear fuels. It is intended where it is required to have corrosion resistance to strong organic acids, such as the naphthenic acids found in the petroleum refining.