THE EFFECT OF PRE-CREEP ON STRESS-CORROSION CRACKING OF AUSTENITIC STAINLESS-STEEL AND BRASS

The effect of pre-creep on the stress corrosion cracking (SCC) of aust enitic stainless steel in a 42% MgCl2 solution and brass in an ammonia solution was investigated using constant load and constant deflection samples. For both austenitic stainless steel and brass, pre-creep had no influence on the failure time and the threshold stress intensity o f SCC if the constant load sample was used. Since for constant deflect ion samples, pre-creep could greatly increase the threshold stress int ensity of SCC for both austenitic stainless steel and brass, constant deflection specimens are not suitable for investigating the effect of pre-creep on SCC. Pre-cathodic protection at a non-cracking potential for long times could inhibit the SCC of brass during subsequent exposu re in cracking potential range. This is, however, attributed to the ch ange of composition and pH value of the solution rather than the effec t of pre-creep.