KREISLOVÁ Kateřina SVÚOM s.r.o.

Současný stav korozního napadení materiálů hutní výroby a jeho hodnocení

Corrosion is one of the most misunderstood and mischaracterized form of material degradation. Corrosion is the term used to describe the degradation of a usually metallic material due to chemical or electrochemical attack by reaction with environment. The metallic surface is attacked through the corrosion and losses its original strength by the thinning of the member. When corrosion eventually destroys a sufficient amount of the structure’s strength, a failure will occur. Corrosion accounts for approximately 40% of all equipment failures in industrial facilities. The metallurgical products may suffer due to corrosion in different stages of their application: - immediately after production – storage and transport of products before afterwards processing, - during other production steps (welding, cutting, drilling, finishing, etc), - during service life at various exposure conditions. In many cases the degradation process is affected by defects of metallurgical structure of metallic materials or defects caused due to other technological treatment of them. Corrosion is a perfectly natural process. The corrosion attack is always the complex effect of a system consisting of one or several metals and such parts of the environment that affect corrosion. Different failure mechanisms can be expected depending on the materials and/or surface treatment selected and on the actual environment. Ca 80% of all metallic materials is exposed in the atmospheric environments. The atmospheric corrosion depens on time of wetness of metallic surface and pollution of atmospheres. In contemporary European atmospheres the SO2 in not the domic effect but even in non marine urban environments the effect of chloride from deicing salts affects corrosion of all structural metals. The consequences of corrosion are many and varied and the effects of these on the safe, reliable and efficient operation of equipment or structures are often more serious than the simple loss of a mass of metal.