STRESS CORROSION OF TYPE-304 STEEL IN H2SO4/NACL ENVIRONMENTS AT ROOM TEMPERATURE

Cracking was iniated mainly as a consequence of grain boundary corrosion but below the outer layer of grains cracking was mainly transgranular. Crack propagation occurred as a result of the formation of parallel tunnels across a grain. The width of tunnels was greater in the larger grain size material. The subsequent formation of the crack surface occurred partly as a result of tearing of tunnel walls because of the stress component acting normal to the fracture plane and partly as a result of lateral dissolution.