一钢轧厂临盆TC420L、T420L 汽车大梁用热轧钢带工艺操纵规程(国外英文资料).doc

一钢轧厂生产TC420L、T420L 汽车大梁用热轧钢带工艺操作规程(国外英文资料) A steel mill produces TC420L, T420L car girder with hot rolled steel belt Process instruction 2011L124 replaces 2010L144 This process is suitable for the production of TC420L, T420L, and girder of the T420L in a steel rolling factory. Number 1 and chemical composition The smelting is produced by the internal control plate, and its composition control is as follows: brand Chemical composition, % C Mn s. P Si Als N (PPM) NTC420L NTH420L NT420L 0.060 ~ 0.080 1.10 ~ 1.20 0.010 or less ? 0.020 0.10 or less 0.015 ~ 0.035 50 or less The target 0.070 1.15 0.008 or less ? 0.015 0.07 0.020 or higher 40 or less Residual elements in steel: Cu, Ni, Cr, less than 0.30% 2 converter operation Requirement of 2.1 raw materials Water conditions of 2.1.1 The entrance to the furnace is less than 0.015% and P is less than 0.120%. The temperature of 1300 ℃ or higher. 2.1.2 steel scrap Internal quality scrap steel. 2.2 end control The finish component: C is less than 0.06%, S is less than 0.020%, P is less than 0.012%. 2.3 deoxygenation 2.3.1 USES the medium carbon manganese iron with manganese, silicon iron with silicon. According to the end of the end, the oxygen is used to deoxidize the aluminium manganese titanium or aluminum iron, and the steel and steel water is added at a quarter of the time, and the alloy material is added before 2/3 of the steel. Added sequence: aluminium manganese titanium or alumina ferro-manganese ferro-silicon-aluminium manganese titanium or aluminum iron - lime or refined slag. The contents of the package are controlled by the lower part of the composition, the Als100 ~ 300ppm (reference value). 3 LF process 3.1 according to the S content in steel, joined the amount of lime and fluorite is determined, in the meantime, by the moderate intensity of argon stirring, and made white slag ladle to join, a suitable thickness of slag foaming, prevent the increase of nitrogen. After the composition is qualified, the calcium p