Development of hot rolled coils in S355J2+N grade with Si content <0.03% on Zelezara Smederevo hot strip mill

Because of suitability for hot-dip zinc-coating, there is some concern about the use low silicon (Si) content in normalized or normalizing rolling S355J2+N structural steel with minimum specified yield strength of 355 MPa. However, decreasing Si content leads to a decrease of solid solution hardening, whereas decrease in strength should be compensated by alternative mechanism. One possible solution is the use of microalloying with niobium (Nb). Based on available results obtained on own and competitive material, we projected and produced S355J2+N hot-rolled coils (HRC). The results show that the produced material fully satisfies the requirements of the EN 10025-2/2004 quality standard. Furthermore, strength values in normalized conditions were lower than those in normalizing rolling condition.