THE EFFECT OF TEMPERATURE AND H2S CONTENT ON THE CRACKING RESISTANCE OF A 13-PERCENT CHROMIUM MARTENSITIC STAINLESS-STEEL IN ACIDIFIED NACL

The cracking resistance of a 13% chromium martensitic stainless steel has been determined, using the slow strain rate technique, as a function of the temperature (23-80°C) and H2S content of acidified NaCl. A clear correlation between relative time-to-failure and sub-surface hydrogen content (Co) has been established at each temperature. However, it is shown that the predominant factor determining cracking is the fractional occupancy of reversible trap sites. A broad correlation has been identified between relative time-to-failure and fractional occupancy of traps irrespective of whether the latter is obtained by varying temperature, H2S content or pH (≤3.6). © 1990.