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本文研究了拉伸速度和充氢时间对D6AC钢力学性能及形交断裂的影响。结果发现:此钢的塑性指标随拉伸速度的提高而增加,随充氢时间的加长而减小。于现有的充氢条件下,在较短的充氢时间里,存在一个临界拉伸速度,大于此拉伸速度时,材料对氢脆不敏感。而且存在着一个临界充氢时间,大于此充氢时间,在各自的拉伸速度下,塑性基本保持不变。从断口观察结果可见:随充氢时间的加长,试样的断裂源由中心移到边部,断裂方式从穿晶转成沿晶,沿晶断口所占比例随充氢时间的增长而增加。在较短的充氢时间里,随拉伸速度的增高,断裂源由边部移到中心。总之,这与氢脆的敏感性随充氢时间的减短和拉伸速度的提高而减小的结果完全一致。
In this paper, the effects of tensile velocity and hydrogen charging time on the mechanical properties and shape breakage of D6AC steel were studied. The results showed that the plasticity of this steel increased with the increase of tensile speed and decreased with the increase of hydrogen charging time. Under the existing hydrogen charging conditions, there is a critical tensile speed in a short hydrogen charging time, and above this stretching speed, the material is not sensitive to hydrogen embrittlement. And there is a critical hydrogen charging time, greater than this hydrogen charging time, at their respective stretching speed, the plastic remained basically unchanged. From the fracture observations, it can be seen that with the increase of hydrogen charging time, the fracture source of the sample moves from the center to the edge and the fracture mode transforms from transgranular to intergranular. The proportion of intergranular fracture increases with the increase of hydrogen charging time. In the shorter charging time, the fracture source moves from the edge to the center with the increase of the drawing speed. In conclusion, this is in good agreement with the reduction of hydrogen embrittlement susceptibility as the hydrogen charging time is shortened and the stretching speed is increased.