Q&P工艺对Fe-0.45C-1.6B高硼钢组织和性能的影响

借助Thermo-Calc、光学显微镜、扫描电镜、X射线衍射仪、洛氏硬度计及冲击磨损试验机对Fe-0.45C-1.6B高硼钢铸态和经Q&P工艺处理后的组织和性能进行分析。结果表明:高硼钢铸态组织由铁素体、马氏体及残留奥氏体构成的基体和共晶硼化物组成。经Q&P工艺处理发现,高硼钢在Ms点以下为马氏体等温转变,随着淬火时间的增加,基体中残留奥氏体越来越多,在淬火时间为120 s时达到极限。随着配分时间的增加,高硼钢中残留奥氏体增加,配分时间为80 s时残留奥氏体量最多,但是由于较多的残留奥氏体不能支撑硼化物,因此高硼钢的耐磨性降低。

Effect of Q&P process on microstructure and properties of Fe-0.45C-1.6B high-boron steel

The microstructure and properties of Fe-0.45C-1.6B high-boron steel as-cast and after quenching and partitioning (Q&P) were analyzed by means of Thermo-Calc, OM, SEM, XRD, Rockwell hardness test and impact wear test. The results show that the as-cast microstructure of the high-boron steel is composed of a ferrite+martensite+retained austenite complex matrix and eutectic borides. Isothermal martensite transformation occurs below the Ms point in the Q&P process, the retained austenite in the matrix increases with the increase of quenching time, and reaches the limit when the quenching time is 120 s. While the retained austenite increases also with the increase of partitioning time, and reaches the maximum when the partitioning time is 80 s. However, more retained austenite causes the matrix too soft to support the boride, the wear resistance of the steel decreases.