COMPARATIVE STUDY OF STRESS CORROSION CRACKING OF 304L AND 316L STAINLESS STEEL IN LOW CONCENTRATION SODIUM HYDROXIDE SOLUTION WITH HIGH TEMPERATURE

摘要

Stress corrosion cracking (SCC) of austenitic stainless steel serviced in aggressive environment often occurs in power, petrochemical industry, and leads to premature equipment failure and great economic loss. This paper focuses on the problem of the SCC on the nozzle of hydrogenation reactor which is caused due to alkali cleaning. Susceptibility for SCC was evaluated by Slow Strain Rate Test (SSRT) for as-rolled 304L and 316L stainless steel (SS) in low concentration sodium hydroxide solution with high temperature. The effects of different concentration of sodium hydroxide and different solution temperatures on SCC were investigated at the strain rate of 1×10~(-6)s~(-1). After SSRT was performed, fractograph of the fractured specimens was analyzed by using scanning electron microscopy (SEM). On the basis of this, fracture characteristic and susceptibility of SCC of 304L and 316L stainless steel were compared in low concentration sodium hydroxide solution with high temperature.