ABSTRACT
A novel processing route is proposed to create a heterogeneous, multiphase structure in a medium Mn steel by incorporating partial quenching above the ambient, warm deformation, and partial recrystallization at high partitioning temperatures. The processing schedule was implemented in a Gleeble thermomechanical simulator and microstructures were examined by electron microscopy and X-ray diffraction. The hardness of the structures was measured as the preliminary mechanical property. Quenching of the reaustenitized sample to 120 °C provided a microstructure consisting of 73% martensite and balance (27%) untransformed austenite. Subsequent warm deformation at 500 °C enabled partially recrystallized ferrite and retained austenite during subsequent partitioning at 650 °C. The final microstructure consisted of a heterogeneous mixture of several phases and morphologies including lath-tempered martensite, partially recrystallized ferrite, lath and equiaxed austenite, and carbides. The volume fraction of retained austenite was 29% with a grain size of 200-300 nm and an estimated average stacking fault energy of 45 mJ/m2. The study indicates that desired novel microstructures can be imparted in these steels through suitable process design, whereby various hardening mechanisms, such as transformation-induced plasticity, bimodal grain size, phase boundary, strain partitioning, and precipitation hardening can be activated, resulting presumably in enhanced mechanical properties.
ABSTRACT
The data available in this article presents the microstructural information achieved via scanning electron microscopy and electron backscatter diffraction to evaluate the microstructure of maraging stainless steel 13Cr10Ni1.7Mo2Al0.4Mn0.4Si, in its as-built and heat-treated conditions, fabricated by laser powder bed fusion. In addition, the statistical analysis of the defects is included to indicate the quality of the additively manufactured metal. Furthermore, true stress-logarithmic strain diagrams of the material with different types of post-processing are available, indicating the strain hardening behavior of the material. These diagrams were achieved via quasi-static tensile tests performed in conjunction with the digital image correlation technique. Finally, the sample designs, additive manufacturing parameters, and the heat treatment procedure carried out on the material are also available in this paper to guide future research and ensure the repeatability of the data in this data article and its linked research paper. The research paper investigates the effects of processing and post-processing parameters on the microstructure, surface quality, residual stress, and mechanical properties of 13Cr10Ni1.7Mo2Al0.4Mn0.4Si (conventionally known as CX developed by EOS GmbH) processed by laser powder bed fusion [1].
