淬火、配分温度及时间对Q&P钢组织及力学性能的影响

Effects of quenching,partitioning temperature and time on microstructure and mechanical properties of Q&P steel

采用扫描电镜、透射电镜等试验手段研究不同Q&P(Quenching and Partitioning)工艺对钢的微观组织和力学性能的影响。结果表明:完全奥氏体化并采用Q&P工艺处理后Q&P钢的抗拉强度为1399~1670 MPa,断后伸长率为13.92%~17.24%;显微组织为马氏体和残留奥氏体,其中马氏体主要为板条状及少量分布在原奥氏体晶界处的块状。经EBSD统计分析:块状马氏体尺寸大小为1~3μm,是在第二次淬火过程中形成的新生马氏体;在相同淬火温度下,抗拉强度随配分时间的延长都有不同程度的下降,适中的淬火温度(210℃)加上适中的配分时间(60 s)可获得最佳伸长率。

Effects of quenching and partitioning parameters on microstructure evolution and mechanical properties of steel were studied by means of seanning elec.tron microscope （SEM） and transmission electron microscope（TEM）. The resuhs show that the tensile strength of Q＆P steel reaches 1399-1670 MPa and the total elongation is 13.92% -17.24% after austenitization and Q＆P process. Tin, nlicrostructure is consisted of martensite and retained austenite. The majority of martensite is lath martensite and a small amount of block martensite located at austenite boundary. Based on EBSD analysis, the block martensite is generated during the second quenching process and 1-3 μm in size. The tensile strength decreases with the increasing of partitioning time. The optimal elongation can be obtained by proper cnmbination of partitioning temperature at 210 ℃ and partitioning time of 60 s.