Duplex Steel Pitting Resistance Equivalent Number
Duplex steel pitting resistance equivalent is a metric for assessing the pitting corrosion resistance of high-alloy steels. It considers the mass fractions of chromium, molybdenum, and nitrogen.
Physico-Chemical Mechanism of Action
The Duplex Steel Pitting Resistance Equivalent (PRE) measures a steel's resistance to pitting corrosion in chloride-containing media. It is based on the mass fractions of chromium, molybdenum, and nitrogen in the steel. These elements create a thin protective layer on the steel's surface that prevents corrosion.
Metallurgical Relevance & Welding Risks
A too low PRE value can cause the steel to quickly show pitting corrosion in chloride-rich environments. This can lead to cracks and failure of components. When welding, it is important to consider the PRE of the steel to ensure a stable joint.
Workshop Practice & Instructions
When selecting a duplex steel for aggressive environments, the PRE value should be at least 35. When welding high-alloy steels, careful selection of the welding process is required to maintain corrosion-resistant properties. If necessary, use special corrosion control methods and monitor cooling steps carefully.