钒对微合金化重轨钢高温塑性的影响

Influence of Vanadium on Hot Plasticity of Microalloying Heavy Rail Steel

用Gleeble-1500D热模拟试验机研究了U71Mn钢(%:0.75C、1.20Mn)和U75V钢(%:0.75C、0.94Mn、0.05V、0.005Al)700～1300℃的高温塑性。结果表明,由于碳氮化钒在晶界和晶粒内部析出,加钒降低微合金化重轨钢的高温塑性,特别是第Ⅲ脆性区(850℃)的塑性。为防止铸坯裂纹出现,铸坯矫直温度应≥900℃。

Hot plasticity of U71Mn steel （% ： 0. 75C, 1. 20Mn） and U75V steel （% ： 0. 75C, 0.94Mn, 0. 05V, 0. 005Al） at 700 - 1 300 ℃ has been studied by using Gleehle-1500D thermo-simulation machine. Results show that as va- nadium carbo-nitride precipitates at grain boundary and inside, the hot plasticity, especially the plasticity at Ⅲ brittle zone （850 ℃ ）, of microalloying heavy rail steel decreases by adding vanadium. The strengthening temperature of cast bloom should be ≥900 ℃ to prevent bloom crack forming.