Grade S31768 stainless steel is a type of stainless steel containing austenitic, ferritic, and martensitic phases. It can be called a “super duplex” stainless steel due to its high strength and corrosion resistance qualities. Grade S31768 steel maintains high toughness, strength, and formability over a wide temperature range.
Chemical Composition
Grade S31768 stainless steel contains elements such as chromium(Cr), nickel(Ni), molybdenum(Mo), and titanium(Ti). Grade S31768 typically consists of the following chemical composition: 0.03% Carbon (C), 0.05-0.06% Manganese (Mn), 0.35-0.45% Silicon (Si), 0.03-0.1% Phosphorus (P), 0.03-0.1% Sulfur (S), 19-21% Chromium (Cr), 10.5-11.5% Nickel (Ni), 3-3.5% Molybdenum (Mo), 0.5-1.0% Titanium (Ti), 0.2% Copper (Cu), 0.2% Iron (Fe), Bal.
Mechanical Properties
Grade S31768 stainless steel has excellent mechanical properties. It has an ultimate tensile strength (UTS) of 800 MPa, yield strength (YS) of 790MPa, and elongation at break of 8%. Grade S31768 also possesses good ductility, cold workability, and hot workability making it well suited for forming and machining operations. Additionally, grade S31768 maintains excellent hardenability with a Rockwell C hardenability of 40-55.
Corrosion Resistance
Grade S31768 stainless steel has excellent corrosion resistance across a wide range of environments. It performs especially well in low pH environments and is highly resistant to pitting and crevice corrosion. Grade S31768 is also highly resistant to stress corrosion cracking (SCC) and is often used in a wide range of industrial applications.
Applications
Grade S31768 stainless steel is used in a variety of applications where high strength and excellent corrosion resistance are required. It is often used in the petrochemical, aerospace, and oil and gas industries. Additionally, it is well suited for applications requiring high strength and formability such as bridge components, fasteners, and vessels.
Conclusion
Grade S31768 stainless steel is a “super duplex” stainless steel due to its high strength and corrosion resistance qualities. It contains elements such as chromium, nickel, molybdenum, and titanium which give it excellent mechanical, corrosion resistance, and formability properties. Grade S31768 steel has a variety of applications, most notably in the petrochemical, aerospace, and oil and gas industries.
