通过显微组织观察和力学性能测定，研究了正火温度对09MnNiDR钢组织性能的影响。结果表明，正火钢的组织为等轴铁素体和珠光体，随着正火温度的提高，钢的屈服强度和抗拉强度下降，延伸率基本不变，冲击韧性得到明显提高。同时应用透射电镜对正火钢珠光体和析出相进行研究，探讨其强化机理。

Effects of normalizing temperature on the microstructure and mechanical properties of 09MnNiDR steel plate were investigated with observation of the microstructure and test of mechanical properties. The experimental results showed that the microstructure of normalized steel was composed of equiaxed ferrite and pearlite. The strength and the toughness decreased with the increasing of normalizing temperature, the elongation was almost unchanged, but the impact toughness was improved greatly. The strengthening mechanism was discussed by studying the laminar space of pearlite and precipitation phase with TEM