Fit for the most rigorous challenges and conditions Aperam gets NORSOK approval Continuously striving for the highest qualifications in safety, value addition and cost effectiveness, Aperam has become the third manufacturer in flat stainless steel products to receive a NORSOK approval for two Duplex grades: DX and DX1803 in hot-rolled coils and sheets up to 2m wide and up to 10mm thick according to the NORSOK standard M-650 Ed. 4. Through their two-phase 50% austenite/ 50% ferrite microstructure, duplex stainless steels exhibit attractive characteristics for the Oil & Gas Industry.