Can duplex stainless steel be used in combination with carbon steel? Will these two materials react with each other?

Duplex stainless steel and carbon steel can be used together, but attention should be paid to their potential differences. In humid environments, electrochemical corrosion occurs in the presence of electrolytes. This type of corrosion causes rusting on the surface of carbon steel, and it also causes significant damage to duplex stainless steel. Furthermore, under certain conditions, carbon steel can also pose a risk of stress corrosion cracking and intergranular corrosion to duplex stainless steel. Therefore, if it is necessary to use duplex stainless steel in combination with carbon steel, effective protective measures should be taken, such as applying cathodic protection current and trying to avoid direct contact between carbon steel and duplex stainless steel. .

Will mutual contamination occur after contact?

After contact, carbon steel may contaminate duplex stainless steel. When carbon steel comes into contact with stainless steel, some particles such as iron flakes and debris may be generated; these particles can adhere to the surface of the stainless steel, leading to rust formation in the area of contact. Furthermore, contaminants such as oil and dust on carbon steel may also adhere to the surface of stainless steel and contaminate it. Therefore, when using them together, care should be taken to prevent direct contact between carbon steel and stainless steel, and the carbon steel should be cleaned and protected to avoid contaminating the stainless steel. .

Or rather, whether a potential difference corrosion will occur between them; compared to stainless steel, which one exhibits greater potential difference corrosion with carbon steel?

Compared to ordinary stainless steels, duplex steel has a lower risk of potential difference corrosion. This is because duplex steel contains higher amounts of corrosion-resistant elements such as chromium and nickel, which provide better corrosion resistance, and its grain boundaries also exhibit good corrosion resistance. Carbon steel, on the other hand, has poor corrosion resistance; it tends to rust in humid environments, and it also poses a risk of potential difference corrosion to duplex steel. When carbon steel comes into contact with duplex steel, the carbon steel may act as the cathode while the duplex steel acts as the anode, which leads to potential difference corrosion and thus damages the surface of the duplex steel. In summary, when using duplex steel in combination with carbon steel, it is necessary to control the potential difference to prevent electrochemical corrosion. .