Abstract: The structure and mechenical properties of Φ52 mm 45MnVTi steel finished rolling at 917～922  ℃ and water-cooling-self-tempering with 680～830 ℃have been tested and researched.Results show that the microstructure of asprepared steel consists of ferrite and pearlite,with the decrease of self-tempering temperature,the yield strength and tensile strength of steel gradually increase,and toughness increases at first and then decreases. When the range of self-tempering temperature is 750 to 770 ℃,the microstructure of steel products is fine ferrite and pealite, and the test steel average value of tensile Strength 841 MPa,yield Strength 547.5 MPa,impact energy 50.5 J with an optimal match between the strength and toughness of steel and pearite lamellar spacing 2.39 μm,to meet the use requirements.

摘要： 试验研究了Φ52 mm 45MnVTi钢终轧917~922 ℃水冷返红680~830 ℃的组织和力学性能。结果表明，随着返红温度的降低，钢材的屈服强度及抗拉强度不同程度的升高，韧性先升高再降低，组织类型为铁素体和珠光体。当返红温度750～770 ℃时，钢材组织为均匀细小的铁素体和珠光体组织，且试验钢的珠光体片间距平均2.39 _μm；钢材的抗拉强度平均841 MPa，屈服强度平均547.5 MPa，平均冲击功50.5 J，强韧性匹配最佳，满足使用要求。