Abstract：The medium carbon bainitic steel consists of sub-micro structured bainitic-ferrite and retained austenite. The retained austenite plays a leading role for the toughness, it can significantly increase the toughness of bainitic steel by refining the size of blocky structure. In order to explore the effect of block structure refinement on mechanical properties and fracture behavior, the two-step bainite isothermal process was used to study the refinement of the bulk structure, mechanical properties, tensile and impact crack behavior of medium carbon (0.3wt%) bainitic steel. Optical, scanning electron (SEM), transmission electron (TEM) microscope, X-ray diffraction (XRD), etc. were used to characterize and analyze the type and size of microstructure, tensile and impact properties, and fracture morphology of the test steel. The results show that compared with the one-step bainite process, the newly formed bainite ferrite in the two-step bainite process divides and refines the bulk martensite + retained austenite, and the work hardens with the increase of true strain The effect of the rate is better; the fracture form is ductile fracture, and the number and depth of the dimples are better than one-step bainite transformation, and the plastic toughness is better.
收稿日期: 2020-01-02
出版日期: 2020-10-16
引用本文:
周松波 胡锋 尹朝朝 吴开明. 块状组织细化对贝氏体钢断裂行为的影响[J]. , 2020, 55(11): 0-0.
Feng Hu. Effect of refinement of bulk structure on fracture behavior of bainitic steel. , 2020, 55(11): 0-0.
2020, Vol. 55 
