In a previous homework, we determined that a tunnel (through-thickness) crack (Y=3.36) of length 16 mm growing from a 12 mm radius hole in a thick plate of 302 stainless steel (18Cr-8Ni) that has the properties listed below, could withstand a stress of 260 MPa perpendicular to the crack before instantaneous failure? What much lower nominal stress would cause the initiation of stress corrosion cracking in this same situation if the sample were exposed to a 42% MgCl2 solution?