Mo对TMCP工艺轧制EH460高强度船体钢组织和性能的影响

Effect of Mo on Structure and Properties of High Strength Hull Steel EH460 Rolled by TMCP Technology

试验用EH460钢(/%:0.06~0.08C,0.20~0.33Si,1.51~1.52Mn,0.003~0.013P,0.002S,0~0.18Mo,0.34~0.36Ni,0.04~0.05Nb,0.05~0.06V,0.013~0.015Ti,0.006~0.026Als)300 mm铸坯由Φ550 mm轧机轧制成60 mm钢板,终轧温度798~817℃,冷却速率5~20℃/s。研究了不含Mo和含0.18%Mo对该钢组织和力学性能的影响。实验结果表明,当冷却速率为15℃时,不含Mo钢抗拉强度645~655 MPa,-40℃冲击功168~200 J,含0.18%Mo钢抗拉强度677~679 MPa,-40℃冲击功48~64 J;对于高强度船板钢EH460,采用含Mo钢,可以提高钢板强度,达到船级社对其强度要求(屈服强度≥460 MPa,抗拉强度570~720 MPa,-40℃冲击功≥46 J),但含较高Mo钢的冲击功降低较多,因此,在实际生产中,高强度船板钢EH460中的Mo含量,宜≤0.15%。

The 300 mm slab of tested steel EH460 （/% ： 0.06 ~0.08C, 0.20 ~0.33Si, 1.51 ~ 1.52Mn, 0.003 0. 013P, 0. 002S, 0 ~0. 18Mo, 0. 34 ~0. 36Ni, 0. 04 ~0. 05Nb, 0. 05 ~0. 06V, O. 013 ~0. 015Ti, 0. 006 -0. 026A1s） is rolled to 60 mm plate by ~p550 mm mill, end rolling tempenture at 798 ~817 ℃ and cooling rate 5 ~20 ℃/s. The effect of no-bearing Mo and bearing 0. 18% Mo on structure and mechanical properties of the steel has been studied. Test results show that with cooling rate 15 ℃/s, of no-adding Mo steel the tensile strength is 645 ~ 655 MPa, -40℃ impact energy is 168 -200 J, and of 0. 18%Mo steel the tensile strength is 677 ~679 MPa, -40℃ impact energy is 48 ~64 J. For the high strength hull steel EH460, the strength of plate shall be increased by adding Mo in steel to meet the ships＇ classification society standard requirement for strength of steel （ yield strength ≥460 MPa, tensile strength 570 ~ 720 MPa and impact energy at -40 ℃≥46 J）, but the impact energy of higher Mo content steel decreases more, therefore in real production the Mo content in high strength bull steel EH460 should be ≤0. 15%.