Electron beam simulation of disruptions into stainless steel

摘要: Abstract The effects of repetitive pulsed heating and melt layer formation on type 304 stainless steel are reported. A line-source electron beam with pulse times 0.5 or 1.5 ms power densities up to 100 kW/cm 2 has been used for 1–40 cycles at 500°C substrate temperatures. Numerical calculations the temperature profiles their time evolution during also carried out. Significant metallurgical changes observed, both in layers adjacent heat-affected zone. Melt depths (10–20 μm) consistent resolidified regions exhibit columnar columnar-dendritic microstructure. Appreciable lateral motion within molten results very rough surfaces localized cracking occurs. Extensive slip deformation is seen zone, low-cycle fatigue crack initiation observed after only 20 pulses. Chemical result from preferential vaporization Mn correlate liquid phase. We suggest that loss high vapor pressure species such as early phases plasma device operation might provide a unique signature impurity introduction mechanism. Disruption melted compositions distinctly different more-nearly stochiometric ratios Mn/Cr/Ni expected sputter erosion.