UNS S31803 is a duplex stainless steel, also known by ASTM grade F51, or its European designation, 1.4462. We offer this complete With EN 10204 type 3.2 certification; a high-level material testing certificate that provides independent assurance of a material’s conformity to specifications.

UNS S31803 is a combination between ferritic and austenitic stainless steels, balancing the strength of ferritic steel with the corrosion resistance of austenitic steel in a 50/50 microstructure. This blend means that S31803 is ideal for demanding applications where strength and corrosion resistance are both necessary, such as in the oil and gas, pulp and paper, and chemical industries.

Pren Number

The Pitting Resistance Equivalent Number (PREN) of S31803 is typically around 34 or higher. This is reflective of the grade’s ability to resist corrosive environments, a PREN of 34 and above is indicative of good to excellent corrosion resistance. This means that S31803 would be suitable for uses in more challenging environments that are subject to pitting corrosion, such as seawater service. This means that in this regard, S31803 would be preferential over grades with a lower PREN such as 316 which offers a PREN of about 25.

Tensile Strength

The tensile strength for S31803 is generally considered to be 620 MPa, potentially extending to broader ranges such as 650-880 MPa depending on the product. This boasts a significant increase in strength when compared to purely austenitic grades such as 304 stainless steel, which typically sit at a 500-700 MPa tensile strength range. This elevated tensile strength allows for a greater level of force when pulling or stretching the material before it is likely to break or permanently deform. This makes S31803 a much better selection for applications that would see the material being pulled under force. This includes, but is not limited to, applications in industries such as chemical/petrochemical, oil and gas, marine, power generation and catering. The tensile strength of S31803 allows the material to handle significant loads reliably, ensuring longevity and safety.

Key Benefits 

When looking at the stress a material can withstand before beginning to deform, S31803 offers a yield strength between 450 MPa and 600 MPa at room temperature. This makes S31803 a high-strength steel as it can be subjected to a large amount of stress before any deformation occurs. As a result, S31803 is useful when being applied to heavy-load environments, such as construction and heavy machinery.

S31803 is also a good choice when considering weldability.  The material offers a lower thermal expansion than austenitic stainless steels which allows for a reduction in distortion and residual stresses during welding. This is vital for structural integrity, enhancing precision and efficiency when welding the material. This in turn will prevent weaknesses that can lead to cracking, corrosion and premature wear, making S31803 a reliable and robust material to use.

S31803 is preferential to other stainless grades for its balance of cost and performance. The high yield strength and PREN mean that it can offer strength and corrosion resistance while still being an affordable choice.

Our UNS S31803 Capabilities

In UNS S31803 we are currently capable of offering thicknesses from 1mm all the way to 100mm, at a maximum length of 12000mm and a maximum width of 3000mm. All materials will be certified to Norsok and the latest pressure equipment directive (PED 2014/68/EU). The material also comes with certificates to EN10204 3.2.

Interested in UNS S31803 (1.4462)?  Contact us today!

Want to know the difference between UNS S31803 & S32205?

Find out here – https://masteel.co.uk/news/s31803-s32205-difference/