CONTINUOUS CASTING PROCESS FOR PRODUCING LOW CARBON STEEL STRIPS AND STRIPS SO OBTAINABLE WITH GOOD AS CAST MECHANICAL PROPERTIES

摘要

A process for the production of lowcarbon steel strips having a good combinationof strength an formability, as cast, anda good weldability after the pickling byusual processes, comprising the followingsteps: casting, in a twin rolls continuouscasting machine (1) comprising pinch rolls(3), a strip with a thickness comprised between1 and 8 mm, having the followingcomposition as weight percentage of thetotal weight: C 0.02-0.10; Mn 0.1-0.6;Si 0.02-0.35; Al 0.01-0.05; S0.015;P0.02; Cr 0.05-0.35; Ni 0.05-0.3; N0.003-0.012; and, optionally, Ti0.03;V0.10; Nb0.035, the remaining partbeing substantially Fe; cooling the stripin the area comprised between thecasting-rolls and the pinch rolls (3); hotdeforming the strip cast through said pinchrolls (3) at a temperature comprised between1000 and 1300 °C until reaching athickness reduction less than 15 %, in orderto encourage the closing of the shrinkageporosities; cooling the strip at a speedcomprised between 5 and 80 °C/s down toa temperature (Tavv) comprised between500 and 850 °C; and coiling into a reel(5) the so obtainable strip.