Intergranular corrosion container modification
Thread Content
There is a crystallizer whose internal medium is ammonium sulfate solution; the equipment is made of 316L material. It is now necessary to add a level gauge port to this equipment. The original equipment required that the stainless steel material and welds undergo tests for intergranular corrosion tendency. Should the material used for the new level gauge, as well as its welds, also be subjected to such tests? Isn’t 316L ultra-low carbon steel? Why is a intergranular corrosion tendency test still required for the original equipment?
The original equipment requires that stainless steel materials and welds undergo tests to determine their susceptibility to intergranular corrosion. Therefore, when installing the welding level gauge, the welding process must comply with the original manufacturing specifications, and the material used for the level gauge must also meet the requirements specified in the original design drawings (such as ultra-low carbon grades, etc.). If you are in a chemical plant, it is advisable to consult the equipment manufacturer regarding the relevant welding process requirements and intergranular corrosion test reports. Of course, it is best to conduct these tests yourselves, so that the welding process can be adjusted to suit the welding capabilities of your own factory
Ultra-low carbon austenitic stainless steels have a lower tendency to intergranular corrosion compared to ordinary austenitic stainless steels, but this does not mean that such a tendency does not exist at all. If the drawings require an intergranular corrosion test, it still has to be carried out.