Mastering of New Rebar Profiles and Roll Materials in the Rolling Production of the EVRAZ ZSMK

Resumo

The 250-1 continuous small-section mill of the JSC “EVRAZ Joint West-Siberian Metallurgical Plant” is specialized in manufacturing rebars No. 10 and No. 12 and equal angles Nos. 2–4 from workpieces with cross sections 100 × 100 mm in size. The production of rebars from carbon and low-alloy steels was mastered according to the standards of Europe, South-East Asia, and America. The production of rebars is performed both by the slitting process and without longitudinal slitting of the breakdown bars. The durability of the rebar roll passes of the finishing stands is, to a great extent, determined by the shape of grooves made at the bottom of the streams and used to form transverse ribs. The lowest durability of the passes of finishing stands is observed in the case of rolling of sections with crescent edges. In these passes, we observe the fractures of the working surface accompanied by the formation of cracks and crumbling. We tested cast iron of different grades intended for rolls of the finishing group with a minimal Shore hardness equal to 60. The best operating parameters were obtained for rolls made of nodular cast iron and alloyed with chromium, nickel, molybdenum, and vanadium.