铬对C-Si-Mn-Nb铁素体贝氏体双相钢相变规律的影响

Effect of Cr on Transformation of Ferrite and Bainite Dual Phase Steels

通过比较C-Si-Mn-Nb和C-Si-Mn-Cr-Nb两种实验钢热变形后的CCT曲线,分析了合金元素Cr对铁素体贝氏体双相钢连续冷却过程相变规律和组织演变的影响。结果表明,Cr可轻微抑制实验钢的铁素体转变,细化铁素体晶粒,但对铁素体显微硬度没有影响。在铁素体转变量很少或未转变的情况下,Cr可增强亚稳奥氏体的稳定性和淬透性,细化贝氏体产物中的铁素体板条和MA岛,提高贝氏体的显微硬度。

By comparing the CCT curve of C-Si-Mn-Nb steel with that of C-Si-Mn-Cr-Nb steel, the effect of Cr on transformation and microstructure evolution during continuous cooling of ferrite and bainite dual phase steels was analyzed. The results show that Cr appreciably restrains ferrite transformation of test steel and refines ferrite grain size, but has few effects on ferrite microhardness. When there are few ferrite transformations, Cr enhances hardenability of metastable austenite, refines size of bainite-ferrite lath and MA islands of granular bainite and enhances microhardness of bainite.