Abstract: The effect of cleanliness and rolling process of two heats of 20R steel-0. 15C,0.008P,0.008S,0.06Mo and 0. 18C,0.009P,0.004S,0.01Mo on low temperature impact energy of steel has been rescarched by 200 kg vacuum induction furnace and 500 mm mill in laboratory.Results showed that the low temperature impact toughness of steel was obviously improved by decreasing S content and inclusion; with steel1180 ℃ heating,1020 ℃ beginning rolling and 800 ℃ finishing rolling, the longitudinal,cross impact energy at -40℃ of0.008% S steel by hot rolled air cooling and hot rolled + 880 ℃ normalizing were respectively  14.7J,10J and 13J,9J,and inclusion rating in steel was A- 1.5 and B- 1.5; the longitudinal,cross impact energy at -40℃ of 0.004% S steel by hot rolled air cooling were 180J,98 J,and inclusion rating in steel was D-0.5;The longitudinal and cross impact energy at -40℃ of0.004% S steel by hot rolled and control cooling(water cooling)increased respectively to 210 J and 146 J with improved bending structure.

Key words: 20R Steel,S Content,Inclusion,Structure,Low Temperature Impact Energy

摘要： 在实验室用200kg真空感应炉和500mm轧机研究了成分(%)为0.15C、0.008P、0.008S、0.06Mo和0.18C、0.009P、0.004S、0.01Mo两种20R钢纯净度和轧制工艺对低温冲击性能的影响。结果表明,降低钢中S含量和夹杂物可明显改善钢的低温冲击韧性:钢在1180℃加热、1020℃开轧和800℃终轧的情况下,0.008%S钢热轧空冷态和热轧+880℃正火态的-40℃纵、横向冲击功分别为14.7 J、10 J和13 J、9 J,钢中夹杂物为A类1.5级,B类1.5级;0.004%S钢热轧空冷后-40℃纵、横向冲击功分别为180 J、98 J,钢中夹杂物为D类0.5级;0.004%S钢经热轧后控冷(水冷),带状组织改善,-40℃纵向和横向冲击功分别增至210 J和146 J。

关键词: 20R钢, S含量, 夹杂物, 组织, 低温冲击功