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借助X射线衍射仪、透射电镜对1Cr18Ni9Ti不锈钢在超音速微粒轰击(SFPB)形变热处理过程中的纳米晶组织演化进行表征。研究结果表明,通过SFPB处理,1Cr18Ni9Ti钢表面获得了纳米组织,晶粒尺寸随着距表面距离的增加而增大,直至与基体粗晶相同;经SFPB处理30min后,表面晶粒尺寸趋于稳定,形成平均晶粒尺寸约16nm的随机取向的等轴状纳米晶。随着SFPB时间的增加,显微硬度显著增大,而试样的抗拉强度和屈服强度先升后降,延伸率降低;表面纳米化后拉伸试样断口为韧窝-微孔聚集型断裂,韧窝形成微孔,微孔相连而产生断裂。
The evolution of nanocrystalline structure of 1Cr18Ni9Ti stainless steel during the heat treatment by supersonic particle bombardment (SFPB) was characterized by X-ray diffraction and transmission electron microscopy. The results showed that the nano-structure was obtained on the surface of 1Cr18Ni9Ti steel by SFPB treatment, and the grain size increased with the increase of the distance from the surface until it was the same as that of the matrix. After SFPB treatment for 30min, the grain size tended to be stable To form randomly oriented equiaxed nanocrystals with an average grain size of about 16 nm. With the increase of SFPB time, the microhardness significantly increased, while the tensile strength and yield strength of the sample first increased and then decreased and the elongation decreased. The fracture surface of nanostructured tensile specimens was dimple-micropore aggregation Fracture dimples form micropores, micropores connected to produce fracture.