What is dual-phase steel?
The term "dual-phase steel" we often use refers to dual-phase stainless steel.Duplex stainless steelMetallographicStructures include approximately50%Ferritic and50%Austenitic. To achieve this structure, the stable elements of the ferritic phase...Cr、Mo、Si、WStabilizing elements of the austenite (such as)Ni、N、MnFerritic (etc.) offsets./The ratio of Austenite depends not only on the alloy elements but also on the heat treatment process.
Section Two:Advantages of Dual-Phase Steel
（1）Molybdenum-containing duplex stainless steel exhibits excellent chloride stress corrosion resistance under low stress.
（2）Molybdenum-containing duplex stainless steel offers excellent pitting corrosion resistance.
（3）Excellent corrosion fatigue and wear resistance properties.
（4）Excellent comprehensive mechanical properties，High strength and fatigue resistance。
（5）Good weldability。
Section 3: Classification of Duplex Steel
The classification of duplex stainless steel is based on its corrosion resistance, which depends on the alloy elements. Our usual practice is to determine it according to the pitting resistance equivalent number.PRENTo differentiate between duplex stainless steels. The pitting resistance equivalent number describes the stainless steel's resistance to localized corrosion in a chlorinated environment.。
PRENThe calculation
PREN = Cr% + 3.3Mo% + 16N%, among whichCr、Mo、NChromium, molybdenum, and nitrogen content, expressed as weight percentages.
Lean duplex stainless steelTypical RepresentativeUNS S32304-EN1.4362), corrosion resistance equivalent number22 - 27Mo-free or with a small amount of molybdenum, suitable for environments not too harsh.
Standard Duplex Stainless Steel(Typical Representative)S32205(EN1.4462), Corrosion Resistance Equivalent Number28 - 38Chromium content22%Molybdenum content3%Corrosion resistance falls within the moderate range.
Super Duplex Stainless Steel(Typical Representation)S32750(EN1.4410)), Resistance to Point蚀 Equivalent Number38 - 43， Chromium content25%Molybdenum content3.5%Nitrogen content0.22-0.3%。
Super Duplex Stainless SteelEquivalent corrosion resistance number greater than45，Suited for extremely harsh environments, commonly used in the oil and gas industry.
