316L stainless steel material was tested using electrochemical techniques (ASTM G39, G61) to determine pitting susceptibility in five fluids. The five fluids consisted of CSM waste solution, two chloride - based salt solutions and two acidizing solutions.
The tests indicated that the salt solutions (KCl and NH4Cl) are responsible for pitting of 316L injection tubing. CSM waste was not found to be corrosive. Acidizing fluids do not aggravate pitting but are quite corrosive to 316L.
It is recommended that chloride solutions be avoided, but if this is not possible, that inhibitors specific to mitigation of pitting be employed with KCl and/or NH4Cl.