Duplex Stainless Steel (1. 4462), Super Duplex Stainless Steels (Zeron 100, SAF 2507, Uranus 52N+), 6 Mo-austenitics (Cronifer 1925hMo, 254 SMO, INCO 256Mo, Al X 6N), UNS 625. Test methods:

ASTM G48B, MTI2 with applied torque between 0,01 - 10 Nm. Washer materials: PTFE, Delrin, Omnia

Results show that Critical Crevice Temperatures (CCT) determined in Iron(III)chloride solutions are: -strongly depending to the applied torque (increase of applied torque induces decrease of CCT) - direct proportional depending to the surface roughness of the specimens (decrease of the surface roughness and application of stresses in the surface lead to increased CCTs.)

CCT to be achieved is strongly influenced by the crevice geometry which itself is governed by the applied torque and the mechanical properties of the washer materials. Findings which could be proved by FE-calculations.