摘要
为提高2205双相不锈钢的使用安全性,采用光学显微镜和力学性能测试等方法,研究了2205双相不锈钢在NaCl溶液中的疲劳裂纹扩展行为。结果表明:与空气中相比,2205双相不锈钢在NaCl溶液中的疲劳裂纹扩展门槛值有降低的趋势,近门槛区的裂纹扩展速率有所提高,并且裂纹扩展由近门槛区向稳态扩展区转变的临界ΔK提高;在稳态扩展阶段,NaCl溶液使裂纹扩展速率显著提高,导致疲劳寿命显著降低;当NaCl浓度在0.5%~26.6%范围内时,随着浓度的增大,稳态扩展阶段的Pairs方程参数m值呈增大趋势,C值呈减小趋势;NaCl溶液中力学和环境因素的交互作用,加速了疲劳裂纹扩展,材料一旦进入稳态扩展就更容易进入高速扩展区并最终发生断裂。
The fatigue crack-growth behavior of 2205 duplex stainless steel （DSS） in the air and different concentration of NaC1 solution was studied by a series of test methods, such as optical microscope and mechanical property test. Results showed that compared with the sample placed in the air, the sample placed in NaC1 solution had lower fatigue crack-growth threshold, and improved crack propagation rate in the near-threshold region. In addition, the critical AK of the crack propagation from the near- threshold region to the steady state expansion stage was improved. In the steady state expansion stage, NaC1 solution improved the crack propagation rate significantly, and therefore the corrosion fatigue life of the sample placed in NaC1 solution was reduced. When NaC1 concentration was in the range of 0.5%-26.6%, with the increase of concentration, the m value of steady-state expansion phase increased, and the C value decreased. The interaction between mechanics and environment accelerated the fatigue crack propagation in NaC1 solution. Once the material entered the steady-state expansion phase, it was easier to enter the high-speed expansion area and finally fracture.
出处
《材料保护》
CSCD
北大核心
2017年第9期27-30,共4页
Materials Protection
