奥氏体化温度对40CrMoVTiNb钢组织和力学性能的影响

Effect of Austenitizing Temperature on Microstructure and Mechanical Properties of 40CrMoVTiNb Steel

用硬度-温度法测定了试验材料的相变温度,研究了不同奥氏体化温度对40CrMoVTiNb钢组织和力学性能的影响。研究结果表明,40CrMoVTiNb钢的相变温度AC1为700~710℃、AC3为820℃。40CrMoVTiNb钢820℃以下温度加热时,随着奥氏体化温度提高,试验材料淬火态的硬度升高,淬火温度为820℃时,淬火态硬度最高,HRC为56.3。试验材料780℃淬火加热时综合性能最佳,抗拉强度为1120 MPa,伸长率为18%,断面收缩率为61.9%,冲击功AKV为107.3 J,组织为回火索氏体和少量铁素体。

The effect of different austenitizing temperatures on the microstructure and mechanical properties of 40CrMoVTiNb steel was studied.The results showed that the phase transition temperature AC1 of the 40CrMoVTiNb steel was 700-710℃and AC3 was 820℃.When the 40CrMoVTiNb steel was heated below 820℃,the hardness of quenched state increased with the increase of the austenitizing temperature.When the quenched temperature was 820℃,the hardness of quenched state was the highest,and the HRC was 56.3.When heated and quenched at 780℃,the material had the best comprehensive properties,including tensile strength of 1120 MPa,elongation of 18%,section shrinkage of 61.9%,impact energy(AKV)of 107.3 J,and the microstructure was composed of tempered soxaustenite and a small amount of ferrite.