Outokumpu’s newest additions to its product portfolio, the high-chromium austenitic EN 1.4420 and high-chromium ferritic EN 1.4622 have been accepted into European EN 10028-7 standard (Flat products made of steels for pressure purposes – Part 7: Stainless steels) on July 13, 2016. Outokumpu refers to EN 1.4622 as Core 4622 and to EN 1.4420 as Supra 316plus, which is Outokumpu’s registered trademark.
Both of the grades, Supra 316plus and Core 4622, are suitable for various end-uses. Austenitic Supra 316plus is alternative to Forta 316L (EN 1.4404). The higher corrosion resistance and strength make it appealing for tank manufacturers, heat exchangers, tube producers in process and heavy industry. Core 4622 is ferritic alternative to Forta 304L (EN 1.4307) for various appliances. The grade thrives especially in applications that require deep-drawing.
Says Product Manager Juha Kela: “We are pleased about getting these two new Outokumpu stainless steel grades into European EN standard. While it is big milestone for us, the real benefit goes to our customers. Supra 316plus has been successfully used for example in Langh Group’s pressure vessel for corrosive chemicals, but without EN standardization, the Particular Material Appraisal (PMA) process was required to prove that the grade is sufficient for the purpose.”
Core 4622 and Supra 316plus fulfil the requirements of the new directive
The new European Pressure Equipment Directive (PED) Directive 2014/68/EU will fully enter into force on July 19, 2016 and replace the European Parliament and the Council Directive 97/23/EC. European EN 10028-7 standard is connected to the new PED and thus Core 4622 and Supra 316plus fulfil the requirements of the new directive. The EN 10028-7 standard will eliminate the need for PMA process and thus these grades can be used as any other pressure vessel stainless steels. Outokumpu will work actively to update the Tornio plant’s scope of approval according to EN 10028-7:2016 as soon as possible.
Kela continues: “Selected customers have tested Supra 316plus and Core 4622 for their products and the standardization will give the official approval stamp on these grades. The feedback from the tank manufacturers and tube producers has been positive. They could switch from EN 1.4404 without changes to their current process or working methods. Core 4622 has been tested for various deep-drawing applications. The greatest customer benefit in these applications comes from the fact that grade is virtually roping free; final products don’t require as much polishing when compared to other ferritic stainless steel which saves time and money in our customer’s processes.”
Prior the European EN standardization Supra 316plus was accepted to following ASTM standards:
- ASTM A240 standard edition 15A as UNS S31655 in March 2015
- Five ASTM standards (ASTM A249/A249M – 15, ASTM A269/A269M – 15, ASTM A312/A312M-15a, ASTM A358/A358M – 15 and ASTM A554 − 15a) for tubular products in October 2015.