返红温度对钒钛微合金非调质钢45MnVTi组织性能的影响

Effects of Self-Tempering Temperature on Microstructure and Performance of Vanadium and Titanium Microalloyed 45MnVTi Non Quenched and Tempered Steel

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2.39μm;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。

The structure and mechenical properties ofΦ52 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 as-prepared 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 2.39μm,to meet the use requirements.