Does sodium nitrite solution cause intergranular corrosion in S30408 material?

(1) It has been found that 304 stainless steel undergoes uniform corrosion in solutions with a sodium nitrite concentration of less than 60%, at temperatures ranging from 25 to 100°C; the annual corrosion rate is less than 0.05 mm/year, which is considered excellent. (2) According to GB/T 21433-2008 \"Testing for intergranular corrosion susceptibility of stainless steel pressure vessels\", for media whose ability to cause intergranular corrosion in stainless steel is not yet known, especially electrolyte solutions such as acid-containing solutions and acid-type salt solutions (which are acidic); note that sodium nitrite solutions are alkaline, with a pH of around 9), if there is no conclusive evidence indicating that such a medium does not possess the ability to cause intergranular corrosion, it is generally necessary to conduct tests for intergranular corrosion susceptibility on the stainless steel containers used in such applications. (3) Whether inspection is required shall be determined by the design unit based on the specific conditions of the pressure vessel.