5. Parameters influencing corrosion

The corrosion kinetics of a material are the result of the oxidation kinetics of the material (anodic process) and the reduction kinetics of the medium in contact with the material (cathodic process). The medium and material involved can be affected by various parameters, such as :

• corrosion products (resulting from oxidation of the material or reduction of the medium), notably with the presence of ions catalyzing the nitric acid reduction reaction;

• oxidizing ions (other than nitric acid) ;

• halides (mainly fluoride and chloride ions);

• temperature and/or heat flow ;

• irradiation;

• the influence of the metallurgical state, especially welds.