Abstract: In view of the unstable impact energy of 30CrNiMo (/% ：0.30C, 0.85Mn, 0.25Si, 0.015P, 0.008S, 0.96Cr, 0.43Mo, 0.78Ni, 0.025Al) high strength quenched and tempered steel bar, normalizing (870-910 ℃)and austenitizing ( 830-870 °C ) temperature two-factor and three-level DOE test design scheme are used to quickly find die best process combination for improving impact energy. The results show that the higher the normalizing temperature, the bigger the grain size after being normalized and quenched, and the smaller the impact energy in steel 30CrNiMo. The Minitab tool is used to make the fitting formula of impact energy response to grain size： 21 °C longitudinal impact energy (J) = 27.11 +7.751 x grain size (grade). The optimum process combination for 30CrNiMo steel is normalizing at 870 °C + austenitizing at 850 °C. Its impact energy is 106 J.

Key words: DOE, Two-Factor, Three-Level, Quenching and Tempering Bar, Impact Energy, Grain Size

摘要： 针对30CrNiMo(/%:0.30C, 0.85Mn, 0.25Si, 0.015P, 0.008S, 0.96Cr, 0.43Mo, 0.78Ni, 0.025Al)高强度钢调质棒材冲击功不稳定的问题，根据DOE试验设计方法，对运用该钢正火温度(870～910℃)、奥氏体化温度(830～870℃)两项因子、三水平的试验方案快速寻找到提升冲击功的最佳工艺组合。对比检测结果发现30CrNiMo钢正火温度越高，淬火后组织晶粒度级别越小，对应冲击功越小。运用Minitab工具制作出冲击功响应晶粒度的拟合公式即：21℃纵向冲击功(J)=27.11+7.751×晶粒度(级)。30CrNiMo钢最佳工艺组合为870℃正火+850℃奥氏体化，其冲击功为106 J.

关键词: DOE, 两因子, 三水平, 调质棒材, 冲击功, 晶粒度