Si含量对超超临界汽轮机转子钢30Cr2Ni4MoV组织和性能的影响

Effect of Si Content on Structure and Mechanical Properties of Ultra Supercritical Steam Turbine Rotor Steel 30Cr2Ni4MoV

30Cr2Ni4MoV钢(%:0.15～0.16C、0.03～0.45Si、0.12～0.14Mn、0.005P、0.005～0.006S、1.62～1.72Cr、3.60～3.63Ni、0.52～0.53Mo、0.07V、≤0.005A1)由10kg真空感应炉冶炼,锻后经930℃空冷+900℃空冷+640℃空冷处理,再经850℃水淬+600℃回火调质处理。试验结果表明,当钢中的Si含量由0.03%增加至0.45%时,钢中马氏体量增加,晶粒更为粗大;钢的抗拉和屈服强度分别从922～936 MPa和868～873 MPa增至1015～1028 MPa和950～959 MPa,但平均冲击功由205 J降至154 J。

Steel 30Cr2Ni4MoV （ % ： 0. 15 - 0. 16C, 0. 03 N 0.45Si, 0. 12 - 0. 14Mn, 0. 005P, 0. 005 N 0. 006S, 1.62 - 1.72Cr, 3.60 -3.63Ni, 0. 52 -0. 53Mo, 0. 07V, ≤0. 005A1） is melted by a 10 kg vacuum induction furnace, forged bar treaded at 930 ℃ air cooling ＋ 900 ℃ air cooling ＋ 640 ℃air cooling, then water quenched at 850 ℃ following tempered at 600℃. Examination results show that as the Si content in steel increases from 0. 03% to 0. 45%, the amount of martensite in steel increases and the grains become more coarse; and the tensile and yield strength of steel increase respectively from 922 -936 MPa and 868 - 873 MPa to 1 015 - 1 028 MPa and 950 - 959 MPa, while the average impact energy of steel decreases from 205 J to 154 J.