强流脉冲电子束FV520B钢表面改性组织及耐腐蚀性能

Surface Modification of FV520B Steel by High Current Pulsed Electron Beam

利用强流脉冲电子束进行FV520B钢表面改性,处理参数包括加速电压27 k V,能量密度5 J/cm2,脉冲次数1到25次。使用扫描电镜、电子探针和X射线衍射分析样品表层形貌、元素分布和相组织变化。经强流脉冲电子束改性后,样品表面形貌细密均匀,晶粒尺寸降至2μm以下,重熔层厚度约4μm并形成沿(200)择优方向的柱状凝固组织。样品表层深约10μm范围内的沉淀硬化颗粒得到有效溶解,成分分布均匀化。在3.5%(质量比)Na Cl溶液中测试电化学腐蚀性能,25次脉冲处理样品的腐蚀电位由原始样品的-0.213 V升至0.038 V,腐蚀速率降低约一个数量级。

The FV520 B steel surfaces were modified with high current pulsed electron beam. The impact of the modification conditions,including the acceleration voltage,energy density and pulse number of the electron beam on the microstructures,depth profile and corrosion rate of the modified surfaces was investigated with scanning electron microscope,electron probe micro-analysis,and X-ray diffraction. The results show that the surface modification significantly improves the microstructures and corrosion resistance. For example,modified at 27 kV,5 J / cm^2 and with 1- 30 pulses,the（ 200） preferentially orientated,uniformly distributed columnar grains,about 2 μm in size,in 4 μm thick remelted layer were observed on the compact,smooth surfaces,accompanied by the dissolution and homogeneous contents re-distribution of the initially precipitated particles in 10 μm thick surface layer. 25 pulses resulted in a positive corrosion potential shift in 3. 5%（ wt）. Na Cl solution from-0. 213 to 0. 038 V,reducing the corrosion rate by nearly one order of magnitude.