MODELING CONDITIONS SUITABLE FOR INITIATION OF STRESS CORROSION CRACKING IN THE HEAT AFFECTED ZONE OF THE CROSS WELD OF AUSTENITIC STEEL PIPES

Steels in the cooling water circuits are most vulnerable to localized corrosion, crevice corrosion or deposit corrosion, intergranular corrosion. Austenitic steels excel in their resistance to corrosive environments. In case of use of the tubes in the cooling circuits is necessary to connect them by welding. Welding of austenitic steel is not the easy process in the field of welding. Place of weld joint then becomes a critical place for mechanical properties, but also for corrosion resistance. For application of invoking of stress corrosion cracking have been selected tubular bodies of the most commonly used steels EN 1.4541 and 1.4571. On these transverse welded tubes were manufactured artificial defects by (EDM) method. For the tests were used modified welds with artificial defect and without it. These defects were intended to localize of future damage. The thus prepared samples were exposed in corrosive environments. To induce stress corrosion cracking for tubular bodies from austenitic steels was used method of exposure in the melt MgCl2.6H(2)O [1]. It is known that method for austenitic high alloy steels, is very sensitive to the presence of local areas and under the influence of tensile stress (and residual stress). Modeling of conditions for crack initiation corrosive damage help to determine how the weld joint behaves in aggressive environment exposure. These knowledges help to prevent accidents. Of course is possible take into account the resulting knowledge in the design and life prediction of cooling water circuits.