双相10钢拉伸变形及断裂过程研究

本文通过不同温度亚温淬火及回火，在10铁中得到具有不同体积百分比及不同强度比的铁素体－马氏体双相组织，并研究了这些组织对钢强度、塑性及拉伸时两相变形行为和断裂过程的影响。结果表明，拉伸时马氏体的变形小于双相组织的平均变形，其差值不仅与马氏体的强度有关，同时还受到马氏体区几何形状的影响。低温回火的试样断裂前的微孔及裂纹只产生于铁素体晶粒内部，断口为韧窝＋准解理的混合型；高温回火后，微孔及裂纹的产生部位不再有明显的选择性，裂纹常常穿越马氏体区扩展，断口全部为韧窝状。

INVESTIGATION OF TENSILE DEFORMATION AND FRACTURE PROCESS OF A LOW CARBON DUAL PHASE STEEL

Effects of the ferrite-martensite dual phase structures with different volume fractions and strength ratios on the strength and plasticity of the low carbon steel (0,11%C) and deformation behavior and fracture process of the dual phases were studied. Experiments indicate that the deformation in m artensite regions is less than the deformation of the bulk. The difference between the two relates not only to the strength of martensite, but also to the shape of the the martensite. Under low temperature tempering, the microcavities and crackings before fracture nucleate only in ferrite, the fractures are mixed in specimens undergoing tempering at higher temperature, however, the sites where microcavities and crackings nucleate have no preference between the two phases, the crackings often, propagate through martensite regions as well and the fractures are all dimple.