Fracture surface (SEM picture) of sensitised AISI 304. Test specimen of a Slow Srtrain Rate experiment in pure water. Intergranular Stress Corrosion Cracking occurred. Foto KEMA) (ref 31).
Fracture surface (SEM picture) of non-sensitised AISI 304. Test specimen of a Slow Srtrain Rate experiment in pure water. Some transgranular SCC occurred. (Foto KEMA) (ref 31).
CERT samples exposed in 0.001 M NaCI at different potential values. The sample diameter
is 2.5 mm. The potentials are given in the photographs: extension rate, 7.5 10-5 mm/s. (Foto KEMA) (ref 31)
Relative stresses and strains of the CERT experiments on AISI 304 in 0.001 M NaCI solution at
200 °C The relative strain and stress values decrease at potentials above +150 mV NHE. Above 300 mV NHE, the relative strain increases again, but the relative stress continues to decrease. The number and depth of the stress corrosion cracks increase at greater potentials (see Figure 5). This results in a lower effective cross section of the specimens; therefore, the relative tensile strength decreases at high potentials. However, the many cracks above + 300 mV exhibit a strong increase in length, resulting in a minimum in the relative strain. (Foto KEMA) (ref 31).
Influence of Cl- en 02 -content on SCC in steel 1.4301 in high temperature water. Speidle collected the results of various authors in this Figure. (Foto KEMA) (ref 64).
Corrosion potential of AISI 304 SS in 200 C water. The water was ammoniated to pH 8.5: linear flow velocity in the autoclave, 0.001 m/s; pressure, 50 bar (the measurements at 274 °C of Indig (9) are also plotted).
Scanning electron and optical micrographs of CERT samples exposed to 0.001 M NaCI at [(a) and (b)] -175 mV and [(c) and (d)] +425 mV. At potentials above +150 mV NHE, typical chloride
stress corrosion cracks [(c) and (d)] were formed. At lower potentials, small brittle surface racks [(a) and (b)] were found [450X for (a) and (c) and 250X for (b) and (d)]. Figure 6(d) shows the branching of the chloride stress corrosion cracks. (Foto KEMA) (ref 31)."
[(a) and (b)] Stress-relieved and [(c) and (d)] solution-annealed samples exposed in an inert gas environment [(a) and (c)] and in 0.001 M NaCI at -400 mV NHE [(b) and (d)]: extension rate, 7.5 10-5 mm/s [100X for (b) through (d) and 1600X for (a)]. (Foto KEMA) (ref 31).
Crack growth rates of AISI 304, T = 200 °C; R = 0.1; f = 0.02Hz. annealed: exp 4 ; sensitised: exp 1, 2 and 3.
Cross section of crack in sensitised (left) and non-sensirtised (right) AISI 304. (Foto KEMA) (ref 43).
Sonde for steam blanketing experiments.(foto KEMA). (ref 64).
Results of the research on corrosion and depositformation in sodium phosphates solutions. (ref 64).
Deposits on various Na/P ratios ranging from 1.2 up to 2.0. The tests strips were under tensile stress and cracking occurred at Na/P ratio < 1.8 because of acid phosphate formation. Foto KEMA) (ref 64).
Deposits on various Na/P ratios ranging from 2.0 up to 3.0. The tests strips were under tensile stress and cracking occurred at Na/P=3.0 because of free alkaline formation formation. Foto KEMA) (ref 64).
Fracture surface (SEM picture) of Incoloy 800 reactorgrade. Tested in a steam blanketing condition: Stress: 70% tensile strength, heat flux: 2 W/cm2; 0.006 mol Na3PO4. (foto KEMA). (ref 64).
Intergranullar fracture surface of the specimen of picture 4665. (foto KEMA). (ref 64).
Intergranular fracture on Incoloy 800 material. (foto KEMA) (ref 64).
The Coordinated Phosphate water Treatment (Following the Na3PO4 line in the diagram) and the Congruent Phosphate water Treatment (following the Na2.6H0.4PO4 line). (ref 64).
The Equilibrium Phosphate water Treatment according to Stodola (ref 64).
Cross section of the specimen in Figurew 4675. (foto KEMA) ref( ).
Fatique fracture started from a corrosion pit under a loose stellite shield in a turbine. (foto KEMA) ref 24).
Under the pockshaped deposits on a Zircaloy fuel element in a Boiling Water Reactor SCC is initiated sometimes. (foto KEMA, ref 61).
Cross section of the fuel element showing nodular corrosion (a), hydriding (b) and a Stress Corrosion Crack (foto KEMA) ref(61).