DP980钢板辊弯成形矩形管过程中的开裂行为

Cracking Behavior during DP980 Steel Plate Roll-Bending to Rectangular Tubing

通过显微组织和微观形貌观察,分析了DP980钢板辊弯成形矩形管过程中的开裂行为。结果表明:DP980钢矩形管在成形过程中,其弯角部位近内表面处的塑性明显低于近外表面处的;弯角处裂纹起裂于内表面,由内表面向外表面沿马氏体堆簇部位扩展;裂纹始端呈穿晶扩展,始端断口呈现解理断裂特征,裂纹末端断口及人工断口呈现准解理断裂与韧性断裂混合特征。

Cracking behavior during DP980 steel plate roll-bending to rectangular tubing was investigated by microstructure and micromorphology observation.The results show that during the forming of the DP980 steel rectangular tubing,the plasticity near inner surface at the corner position was significantly lower than that near the outer surface.Cracks at the corner initiated from the inner surface and propagated along the location of martensite aggregation from inner surface to outer surface.At the initial stage,the cracks propagated in transgranular mode,and the fracture was cleavage fracture.The fracture at the end of cracks and the artificial fracture showed a mixed feature with quasi-cleavage fracture and ductile fracture.