Laser-melted surface layer of steel X165CrMoV12-1 and its tempering characteristics

The transformation of material treated by laser-melting needs to be elucidated in order to enhance the development of laser technology. The steel X165CrMoV12-1 was treated by laser-melting, resulting in a layer of undercooled austenite on the surface of the steel. Austenite has a strong stability. Although it contains high levels of carbon and chromium, the austenite transformed into lath martensite after tempering at 550°C. The transformation is thought to be caused by the matrix structure determined by austenite solidification.