Most insulation contains plenty of chlorides and piping is frequently under tensile stress. The worst condition would be insulated steam traced, stainless steel piping. If it is necessary to insulate stainless steel pipe a special chloride free insulation can be purchased or the pipe can be coated with a protective film prior to insulating. Stress cracking can be minimized by annealing the metal, after manufacture to remove residual manufactured stresses. Never replace a carbon steel bolt with a stainless steel one unless you are sure there are no chlorides present.
Bolts can be under severe tensile stress.
No one knows the threshold values for stress cracking to occur. We only know that you need tensile stress, chlorides, temperature and the 300 series of stainless steel. We do not know how much chloride, stress or temperature. I had trouble breaking stainless steel fishing hooks in the warm water we have in Florida. Many cleaning solutions and solvents contain chlorinated hydrocarbons.