CORROSIVITY OF BR- AND CL- ON DUPLEX STAINLESS-STEEL

This report discusses the basis for material selection in chemical plants, especially focusing on the design of an actual plant based on laboratory corrosion test results. Both the chemical system created when chlorine gas and bromine gas were neutralized with alkaline solution, and material economics are considered when selecting duplex stainless steel as a construction material. In addition, the corrosivity of Br- and Cl- with or without BrO- and ClO- on duplex stainless steel is discussed in terms of pitting and crevice corrosion. Br- ions show a lower tendency to promote pitting and crevice corrosion on duplex stainless steel, compared with Cl- ions. BrO-, existing in a bromine gas neutralization system, acts as a strong oxidizer and easily shifts the corrosion potential of duplex stainless steel more noble, drastically promoting crevice corrosion.