Time resolved Bragg edge neutron radiography for observing martensitic phase transformation from austenitized super martensitic steel

Neutron Bragg edge imaging was applied for the visualization of a amp; 947; austenite to amp; 945; amp; 8242; martensite phase transformation. In the present study, a super martensitic stainless steel sample was heated until complete austenitization and was subsequently cooled down to room temperature. The martensitic phase transformation started at Ms 190 C. Using a monochromatic neutron beam with amp; 955; 0.390 nm, the transmitted intensity was significantly reduced during cooling below Ms, since the emerging martensitic phase has a higher attenuation coefficient than the austenitic phase at this wavelength. The phase transformation process was visualized by filming the transmission images from a scintillator screen with a CCD camera with a temporal resolution of 30 s and a spatial resolution of 100