Industrial applications stress corrosion cracking

In practice, inhibitors are often defined according to their field of application. In aqueous environments, inhibitors for acid environments are typically used to minimize metal corrosion during pickling of steel, an operation that removes oxide scales by dissolution in an acid. In the petroleum industry, large quantities of inhibitors for acid environments are used to avoid corrosion of drilling equipment. Inhibitors for neutral environments are used above all for the protection of cooling-water circuits. Inhibitors not only reduce the rate of uniform corrosion, but they also serve to protect metals from localized corrosion and stress corrosion cracking [18]. 

Type 430 stainless is resistant to chloride stress corrosion cracking and elevated sulfide attack. Applications are found in nitric acid services, water and food processing, automobile trim, heat exchangers in petroleum and chemical processing industries, reboilers for desulfurized naphtha, heat exchangers in sour-water strippers and hydrogen plant efluent coolers. The compatibility of type 430 stainless steel with selected corrodents is provided in Table 7.4, which is taken from Reference [1]. 

These alloys represent another version of Ni-Cr-Fe alloys and contain 30-44% of nickel. Alloy 800 of this series has been extensively used in heat exchangers in the petrochemical industry, because of its excellent resistance to stress corrosion cracking in chloride environments and cracking in polythionic acid. It offers an excellent resistance to creep and rupture. They are used for high environments where resistance to oxidation and corrosion is required. Incoloy 825 has proved highly successfiil in applications in H2SO4, HCl, phosphoric acid and clean and polluted seawater. 

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