CORROSION DAMAGE TO THE CONVEYOR BELT OF A FURNACE FOR THE REMOVAL OFSOIL FROM ORGANIC CHLORINE COMPOUNDS

This paper reports the corrosion behaviour of metallic materials which were used in components of a conveyor belt of a decontamination furna ce or of which specimens were attached to the belt for testing purpose s. The furnace was used for decontaminating soil containing organic ch lorine compounds. A total of 1 ferritic and 8 austenitic steels, 9 nic kel base alloys, 2 cast steels with 15 % Si and 15 % Si + 5 % Cr respe ctively, and 3 aluminised steels were tested and afterwards investigat ed by metallographic and micro-analytical methods. Most of the materia ls failed due to external and/or internal corrosion, preferentially al ong grain boundaries. The 2 cast steels revealed fairly good corrosion resistance. The material 2.4061 (LC-NI 99.6) displayed surprisingly g ood behaviour, however it remains to be seen whether the inward migrat ion of O and C along grain boundaries causes embrittlement. The materi als 2.4610 and 2.4831, containing 14-17% Mo and 8.5-9,5 % Mo respectiv ely, showed good resistance. The reason for this good corrosion resist ance could not be clarified. One reason may be the relatively high Mo content but other materials with a comparable Mo content, like materia ls 2.4856 and 2.4663, were significantly attacked. It appears necessar y to check the long-term behaviour of these two materials.