SERMATECH KOREA

Generally metal in the air are combined with oxygen to form oxide(M + O2 → MO2), and metal in solution such as sulfuric acid, hydrochloric acid, and seawater exists in ion as a result of dissolution. These two chemical reactions to lose unique features of metal can be regarded as corrosion and if combined with physical damage(wear, erosion, galling, etc), the reactions can be divided as corrosion-erosion, corrosive wear, fretting corrosion ,etc.

Three chemical-physical reactions above are main causes for chemical plant degradation, and to protect the plant many studies have been proceeded. In the past rubber and Urethane coating, plastic coating, glass coating and Ni & Cr plating are conventionally applied to protect the plant. Though the conventional coating above have good resistance to corrosion, those are weak to thermal operation even 100℃ above, which can't be used as maintenance method in most of harsh environment.

Major ingredients for corrosion in chemical plant are HCl, H2SO4, HNO3, Na2SO4, NaCl, PbO, etc. When the corrosive ingredients are present above the critical temperature, corrosion rate are increased. So, corrosion resistant coating to guarantee longer service life for chemical plant should have low weight change in corrosive condition and superior resistance to oxidizing or non-oxidizing acid.