材料期刊网

利用离子能量为300 keV、束流密度为200 A/cm2、脉冲宽度为75 ns的混合离子束(70%H++30%C+)组成的强流脉冲离子束(HIPIB)对316L不锈钢进行了表面辐照处理, 辐照次数分别为1, 5, 10次. 采用SEM, XRD, TEM和EPMA分析辐照后试样表面形貌、表面层相组成和微观结构及元素分布的变化. 结果表明, HIPIB辐照使试样表面光滑化, 表面层晶粒细化、产生择优取向, 杂质元素选择性烧蚀, 电化学腐蚀性能明显提高. 由于HIPIB辐照引起的大应力和冲击波的影响, 辐照后在深度达100μm表层内显微硬度提高, 表面摩擦系数降低, 表面抗磨损性能显著改善.随着辐照次数的增加, 316L疲劳极限和蠕变断裂寿命延长, 稳态蠕变速率降低.

The surface of 316L stainless steel was treated by high-intensity pulsed ion beams (HIPIB) with ion energy (70% H+, 30% C+) E = 300 keV, current density J = 200 A/cm2, shot number N = 1, 5, 10, pulse duration τ = 75ns. The surface morphology and the phase structure in the near surface region of original and treated specimens were analyzed with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electron probe microanalysis (EPMA) was used to study the distribution of elements on the irradiated specimens. It is found that the HIPIB irradiation can smooth the surface of the targets, and the preferred orientation was present in the surface layer of the treated specimens. Otherwise, selective ablation of impurities occurred during the interaction between HIPIB and the targets. The microhardness was increased in a depth range of up to 100 μm due to extremely high stresses and shock waves induced by the bombardment, so as to the friction coefficient of the irradiated surfaces was reduced and the wear resistance of them was improved significantly. Under the cooperation of the smooth surface and the grain refinement with the selective ablation of impurities, the electrochemical corrosion resistance of 316L was enhanced markedly. HIPIB irradiation prolongs the fatigue limit and creep rupture life of 316L, simultaneity reduces the steady creep rate with increasing the shot number.