配分温度对0.2C-2.96Mn-1.73Si钢组织和力学性能的影响

对0.2C-2.96Mn-1.73Si钢进行IQP(Intercritical heating quenching and partitioning)处理,获得超细化铁素体、马氏体和残留奥氏体多相组织。采用SEM、XRD和拉伸试验机研究了配分温度对试验钢显微组织和力学性能的影响。结果表明,随配分温度的升高,试验钢的抗拉强度逐渐下降,屈服强度和伸长率均先增大后减小。试验钢中残留奥氏体含量随配分温度的升高呈先增加后降低的趋势。配分温度为400 ℃时,残留奥氏体的含量最高,TRIP效应能够提供持久的加工硬化,试验钢获得了最高的均匀变形能力,抗拉强度为1444 MPa,伸长率为20.13%,强塑积达到29 GPa·%,综合力学性能最佳。

Effect of partitioning temperature on microstructure and mechanical properties of 0.2C-2.96Mn-1.73Si steel

Multiphase structure composed of ultrafine ferrite, martensite and retained austenite was obtained in 0.2C-2.96Mn-1.73Si steel by intercritical heating quenching and partitioning (IQP) heat treatment. The effect of partitioning temperature on microstructure and mechanical properties of the tested steel was researched by means of SEM, XRD and tensile testing machine. The results show that with the increase of partitioning temperature, the tensile strength of the tested steel gradually decreases, and the yield strength and elongation first increase and then decrease. The content of retained austenite in the steel first increases and then decreases with the increase of partitioning temperature. The volume fraction of retained austenite is the highest when the partitioning temperature is 400 ℃, the tested steel has the highest uniform deformability because lasting work hardening can be provided by TRIP effect, and displays excellent comprehensive mechanical properties with ultimate tensile strength of 1444 MPa, elongation of 20.13% and the product of strength and elongation of 29 GPa·%.