高覆盖率下超声冲击处理改善AISI 304力学性能研究

Investigation on Mechanical Properties of AISI 304 Treated by Ultrasonic Impact Treatment under High Coverage Rate

以AISI304材料为例,实验研究了在高覆盖率下超声冲击处理后GNG/CG(Gradient nano-grained on the coarse-grained substrate)材料的力学性能,分析了覆盖率、应力状态、应变率对力学性能的影响。结果表明,随着覆盖率的增加,GNG/CG304不锈钢的屈服强度逐步提高,塑性降低,应变率敏感系数提高,双轴应力状态下变形能力提高。高覆盖率冲击处理得到的GNG/CG结构能够有效抑制NG层的局部塑性应变,从而在提高材料强度的同时,保持良好的塑性。

Using AISI 304 as an object, the mechanical properties of GNG/CG（Gradient nano-grained on the coarse-grained substrate） materials produced by ultrasonic impact treatment（UIT） with high coverage were experimentally investigated, and the effects of the coverage, stress states, strain rates on the mechanical properties of materials were also studied. The results showed that the yield strength was gradually enhanced with the increase of the coverage at the expense of plasticity. GNG/CG 304 possessed very high strain rate sensitivity coefficient, and biaxial stress state could enhance the ductility of GNG/CG materials. The GNG/CG structure processed by UIT with high coverage could suppress the strain localization of NG layer effectively, and could improve the mechanical performances of AISI 304 with a balance of strength and ductility.