抄録
The susceptibility to stress corrosion cracking (SCC) in boiling 42% MgCl2 solution was examined crystallographically for the cold worked SUS 304 steel single crystals with two tensile axis orientations.
The susceptibility to SCC of cold worked single crystals was dependent on tensile axis orientation: The threshold stress for SCC occurrence in the single crystal of multiple slip system was lower than that of single slip system. In this case, the crack initiation of both single crystals was suppressed by cold-working. Once that the cracks initiated, however, they propagated rapidly. The fracture surface of SCC was formed by the macroscopic crack growth along ‹110› direction on {100} plane, regardless of tensile axis orientation. However, the microscopic crack morphology was influenced by tensile axis orientation, which was characterized by plate-like pattern: The stereo analysis technique revealed that the macroscopic {100} plane was composed of the crack planes along primary slip plane and conjugate slip plane in the single crystal of single slip system, while along four equivalent {111} planes in that of multiple slip system.
