Influence of irradiation number of high current pulsed electron beam on the structure and properties of M50 steel

Various categories of defects after surface alloying induced by high current pulsed electron beam irradiation

“…3a ande. The diameter of these craters was much smaller than that of the craters described in some literatures [20,29]. This effect might be explained by the columnar crystal structure (Fig.…”

“…The parameters of electron gun are max accelerating voltage ∼40 kV, peak current ∼30 kA, pulse duration 2-5 s, beam diameter up to 100 mm, and energy density 1-20 J/cm 2 [23,24]. The working chamber was evacuated by a molecular pump to a pressure of 1 × 10 −3 Pa. During the irradiation, pulsed duration, energy density, the number of pulses, accelerating voltage, pressure and distance between sample and cathode of electron gun were important contributors to the effect of surface alloying [20,[25][26][27][28]. Irradiation of samples was carried out in argon at pressure of 4 × 10 −2 Pa.…”

“…However, it was common that crater-like defects and cracks were formed under irradiation [18][19][20][21]; while it might decrease the quality of surface alloying.…”

Investigation of microstructure and thermal stability of pulsed plasma processed chromium ferritic-martensitic steels

“…Hence, the optimization of surface structure has become a feasible and effective method of improving the overall properties of structural materials. Relatively novel methods such as ultrasonic treatment [1], electron and ion beams [2,3], pulsed laser and plasma irradiation [4,5] have been admitted as a promising methods for surface modification over the last few years. Such treatment results in the evolution of dislocation structure of the material, grain refinement and increase of the grain misorientation angles, etc., and eventually allow to create nanocrystalline materials.…”

“…Ultrafine grains and large density of grain boundaries of nanomaterials possess unique properties in particularly increased strength/hardness, enhanced diffusivity, improved toughness/ductility, corrosion and erosion resistance. Numerous papers have been focused on the investigation of the nanostructuring methods and unique properties of produced materials [1][2][3][4][5], though, their thermal stability for high temperature applications such as nuclear and fusion industry is far from being clarified. …”