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用Fe-3％Si单晶试样对氢致解理断裂进行了研究。结果表明,Fe-3％Si单晶缺口试样在空气中拉伸时一般不发生解理,但在动态充氢条件下,即使室温慢加载也能产生解理断裂。对于Ⅰ+Ⅱ复合型试样,氢致裂纹并不沿断裂力学预示的开裂角扩展,而是沿解理面扩展,即氢促进了解理断裂。无论Ⅰ型还是复合型,氢致解理裂纹的da/dt—KⅠ曲线都由三个阶段组成,但Ⅰ型试样da/dt的平台值明显地比复合型的高。用各向异性断裂力学计算了作用在裂纹前各滑移系上的分切应立力,并配合断口观察确定了解理裂纹形核机理。研究了氢的促进作用。
Hydrogen induced cleavage was investigated using Fe-3% Si single crystal samples. The results show that the Fe-3% Si single crystal notched samples generally do not cleave when stretched in the air, but cleavage fracture can occur even under slow charge at dynamic charge. For the I + II composite samples, the hydrogen induced cracks do not extend along the crack initiation angle predicted by fracture mechanics, but extend along the cleavage plane, ie hydrogen promotes cleavage fracture. Both da / dt-KI curves of hydrogen-induced cleavage crack are composed of three phases, no matter the type I or the composite type, but the type I da / dt plateau value is significantly higher than the composite type. The anisotropy fracture mechanics was used to calculate the stand-off force acting on each slip system before the crack, and the nucleation mechanism of cleavage crack was confirmed with fracture observation. The promotion of hydrogen was studied.