| 摘要 |
PURPOSE:To produce high ductility and high yield point steel at a low cost in reduced stages by casting steel contg. specific amts. of C, Si, Mn, Ti, N, Al continuously, and ending hot rolling at temps. higher than specific temp. directly or after heat holding. CONSTITUTION:The steel consisting of 0.02-0.10% C, <=0.05% Si, 0.10-0.80% Mn, 0.002-0.02% Ti, <=50ppm N, 0.005-0.05% Al and unavoidable impurities is cast continuously. This high temp. ingot is directly hot rolled or is completed of hot rolling at temps. higher than the Ar3 point by way of a soaking stage of holding its heat or light heating. With this steel, the degradation of its ductility by the deposition of carbonitride of Ti deposited in the direct rolling state is obviated by the addition of a limited amt. of Ti in particular, and in spite of this, the ferrite structure is fined and the strength is increased. In this way, the original unit of fuel in the production of the high ductility and high yield point steel is reduced. |
