Abstract: The production process flowsheet of tested steel 16MnT (/%: 0.14~0.15C, 0.27〜0.30Si, 1.40Mn, 0.008~0.010P, 0.003~0.004S, 0.020~0.025Nb, 0.10V, 0.002〜0.08Ti, 0.025~0.027Al, 0.0043~0.0053N) is 60t EAF-LF-VD-5.8 t ingot casting-Ф190~250mm forging- normalizing at 920℃. Examination results show that the impact energy of forged-normalized 0.08%Ti steel 16MnT at -20°C is 6~16J, it is lower than the value of standard requirement-34J. The analysis results obtain that large amount TiN and along grain boundary precipitated phase Nb-Ti ( C, N) exist in 0.08%Ti steel and the fracture of steel at -20T is typical brittle fracture along grain boundary, and the structure of forged product section is non-homogeneous, at surface it is sorbite while at centre of section it is ferrite+pearlite. With decreasing the Ti content in steel to 0.002% and controlling the 1.5m distance between forgings during normalizing wind-fog cooling process, the impact energy of forged product of steel 16MnT at -20℃ increases to 132~288J.

摘要： 试验16MnT钢（/%:0.14~0.15C,0.27~0.30Si,1.40Mn,0.008~0.010P,0.003~0.004S,0.020~0.025Nb,0.10V,0.002~0.08Ti，0.025~0.027Al，0.0043~0.0053N）的生产工艺流程为60t EAF-LF-VD-5.8t铸锭-锻造Ф190~250mm棒材-920℃正火。检验结果表明,0.08%Ti 16MnT钢锻造正火后-20℃冲击功为6~16J,低于标准值34J。分析结果得出,0.08%Ti钢中存在大量TiN和延晶Nb-Ti（C,N）析出相,-20℃钢的断口为典型沿晶脆性断裂,且锻材断面的组织不均匀,表面为索氏体,心部为铁素体+珠光体。通过将钢中Ti含量降至0.002%,正火风雾冷却时锻材间距离为1.5m,使16MnT钢锻材的-20℃冲击功提高至132~288J。

关键词: Ti, 微合金电机轴用钢16MnT, 锻材, 正火工艺, 低温冲击性能