Abstract: Coarse grains occurred in the non-quenched-tempered steel 48MnV (% : 0. 45 ~0. 51C, 0. 90 ~ 1. 20Mn, 0. 05 〜0. 10 V ) produced by 100 t EAF-LF ( VD) -300 mm x 320 mm casting-continuous rolling process. As added 0. 030% 〜0. 050% Ti in steel, the rating of grain in 125 mm x 125 mm square bar rolled with 13 passes was 3 ~ 4 ； the rating of grain in Φ141 mm roun(i bar ( contained 0. 030% 〜0.053% Ti) rolled with 9 passes was 4 ~5; but as added 0. 018% ~0. 035% Ti and 0. 021 % 〜0. 029% Nb in steel, the rating of grain in Φ141 mm round bar rolled with 9 passes was 5. 5 〜6. 5 in order to obviously increase strength and toughness of steel.

Key words: Non-Quenched-Tempered Steel 48MnV, Continuous Casting and Rolling, Ti-Nb, Grain Refining

摘要： 用100 t EAF-LF(VD)-300 mm×320 mm连铸-连轧工艺生产的48MnV钢(%:0.45～0.51 C、0.90～1.20Mn、0.05～0.10V)出现粗大晶粒,经13道次轧成的125 mm×125 mm方钢(0.030%～0.050%Ti)的晶粒度为3～4级,经9道次轧成的Φ141 mm圆钢(0.030%～0.053%Ti)的晶粒度为4～5级;但通过加0.018%～0.035%Ti和0.021%～0.029%Nb后,经9道次轧制的Φ141 mm圆钢的晶粒度达5.5～6.5级,显著提高钢的强韧性。

关键词: 非调质钢48MnV, 连铸连轧, Ti-Nb, 晶粒细化