充氚不锈钢微观组织及断裂特征
Fracture Mechanism of Stainless Steel Charging With Tritium
-
摘要: 采用力学拉伸实验测定充氚不锈钢的断裂强度值，采用拉伸断口进行SEM观察和正电子湮灭（PAT）分析，采用TEM动态拉伸实验观察和记录材料在微观断裂过程中的行为，通过对比分析氚对不锈钢断裂过程的影响。结果表明，高温充氚后，室温存放2 a，样品中氚衰变产生的氦累积已达约30 ppm；氚、氦使样品断裂强度降低，内部缺陷增多，正电子寿命变长。TEM观察未发现明显的氦泡组织；动态拉伸实验表明，充氚促进裂纹尖端位错的发射和增殖；HR-1、HR-2不锈钢微观断裂过程相似，可表述为氚致微裂纹的形核-形成微空洞-微空洞长大-空洞连接(断裂)。氚、氦使无位错区减小甚至消失。Abstract: Based on diffusion equation, the concentration of hydrogen isotopes and helium in the stainless steel film specimen aging at room temperature for two years was calculated and measured by finite diffusion method. The fracture strength was measured by tension test. The SEM and PAT were applied for the investigation of the fracture. The initiation and propagation of cracks were investigated in situ by tension in TEM at room temperature. The effect of tritium on the fracture of stainless steel was evaluated. The results show that the concentration of helium from the decay of tritium in the stainless steel aging at room temperature for two years is up to 30 ppm. The fracture strength decreases by the existence of helium and tritium. The increase of the defects makes the lifetime of positron annihilation longer. There are no helium bubbles by TEM. The tension process in TEM indicates that the tritium provokes the emission, propagation of dislocation in the cracks tip. The micro fracture process of HR-1 SS and HR-2 SS can be described that tritium cracks nucleate, blunt to microvoids and then incorporate into crazing tritium which results in the lessening or vanishing of the dislocation free zone (DFZ) for HR-2 SS.
-
Keywords:
- tritium ,
- helium ,
- concentration distribution ,
- fracture strength ,
- micro defect fracture
-
-
[1] 春雷. 核武器概论[M]. 北京：原子能出版社，2000：91. [2] 任大鹏，邹觉生，倪然夫，等. 氢氚对不锈钢力学性能的影响[J]. 兵器材料科学与工程，2002，25(1)：31-34.
REN Dapeng, ZOU Juesheng, NI Ranfu, et al. Effect of hydrogen and tritium on mechanical properties of stainless steel[J]. Ordnance Material Science and Engineering, 2002, 25(1): 31-34(in Chinese).[3] 任大鹏，邹觉生，倪然夫，等. 不锈钢充氚后的微观组织研究[J]. 机械工程材料，2002，26(8):15-17.
REN Dapeng, ZOU Jueshen, NI Ranfu, et al. TEM study of tritium effect in stainless steel[J]. Materials for Mechanical Engineering, 2002, 26(8): 15-17(in Chinese).[4] 向士凯，任大鹏，邹觉生，等. 充氚对不锈钢显微组织及拉伸性能的影响[J]. 金属学报，2001，37(4)：373-376.
XIANG Shikai, REN Dapeng, ZOU Juesheng, et al. Influence of charging tritium on the microstructures and tensile properties of stainless steels HR-1, HR-2 and 1Cr18Ni9Ti[J]. Acta Metallrugica Sinica, 2001, 37(4): 373-376(in Chinese).[5] 陈长安. 氚在不锈钢中的行为研究[D]. 北京：中国工程物理研究院，1998. [6] 褚武扬. 氢损伤和滞后断裂[M]. 北京：冶金工业出版社，1988：20. [7] 褚武扬. 氢损伤和滞后断裂[M]. 北京：冶金工业出版社，1988：513. [8] 王佩旋，宋加树. 材料中的氦及氚渗透[M]. 北京：国防工业出版社，2002：13.
计量
- 文章访问数: 678
- HTML全文浏览量: 0
- PDF下载量: 990
下载:
