A COMPREHENSIVE STUDY OF THE STRUCTURE AND PROPERTIES OF 03H17N12M2 STAINLESS STEEL PRODUCED BY SELECTIVE LASER MELTING

Abstract

Comprehensive studies of the physical and mechanical properties and structure of chromium-nickel austenitic stainless steel 03H17N12M2 (Russian analog of 316L steel) produced by selective laser melting have been carried out. The values of density, tensile strength, microhardness, shear modulus, nanohardness and Young's modulus were obtained, as well as the results of studying the structure and phase composition using scanning electron microscopy, electron backscatter diffraction, and X-ray diffraction. The obtained values of mechanical properties exceed the mechanical properties of steel 316L stainless steel of a similar composition, produced using both traditional technologies and selective laser melting. In order to conduct a more detailed analysis of the features of the material produced by the selective laser melting and to identify the features of the emerging structure depending on the volumetric energy density, additional studies were conducted, such as determining the proportion of low-angle boundaries, determining residual stresses and the proportion of elastic deformation during nanoidentation. It is shown that a change in the volumetric energy density in the considered range 45–130 J/mm³ has a negligible effect on the physical and mechanical properties of the material. However, the cooling rate during selective laser melting, which depends on the volumetric energy density, has a significant impact on the parameters of the emerging structure at the microlevel, such as the type of grain boundaries, the density and mobility of dislocations, etc., which can be an important factor when using the material.