研究了正回火温度对低合金铸钢显微组织及力学性能的影响。结果表明,铸钢正火后的组织为贝氏体型铁素体,890℃正火钢的硬度最大。铸钢经890℃正火,500~650℃回火后,组织转变为保留贝氏体痕迹的索氏体和铁素体;随回火温度升高,钢的硬度和抗拉强度先增大后减小,伸长率先减小后增加。890℃正火,560~590℃回火后钢具有较优的综合力学性能。 The effect of normal tempering temperature on microstructure and mechanical properties of low alloyed cast steel was studied. The results show that the structure of normalized cast steel is bainitic ferrite, and the hardness of normalized steel at 890 ℃ is the highest. The cast steel was normalized at 890 ℃ and tempered at 500-650 ℃. The structure changed to sorbite and ferrite which retained bainite marks. With the increase of tempering temperature, the hardness and tensile strength of steel increased first After the decrease, the elongation decreases first and then increases. After normalizing at 890 ℃ and tempering at 560 ~ 590 ℃, the steel has better mechanical properties.