ABSTRACT

Microstructure optimization of steel for improved performance requires detailed knowledge of the thermal response of the materials. When designing heat treatments of new materials in-situ information about, for example, phase transformation, is pivotal. In this work, the use of two complimentary techniques for in-situ monitoring of thermal behavior of carbon and nitrogen containing steels, i.e., dilatometry and combined calorimetry and thermogravimetry is presented. To illustrate the importance of in-situ techniques for understanding materials behavior, 3 different examples are presented. The examples presented are 1) high carbon martensitic (stainless) steel overspray powders for additive manufacturing; 2) high temperature solution nitriding and the role of nitrogen on microstructure in conventional martensitic stainless steel; and 3) additively manufactured 17-4PH martensitic stainless steel and the role of nitrogen. It shows how in-situ techniques can be applied to record the heat treatment response of these generically different special materials. It is also emphasized how nitrogen can be actively used in steels, which can pave the way for more widespread use of nitrogen containing steels. In addition to in-situ techniques, light optical microscopy and X-ray diffraction analysis are used for characterization.  

Author(s): Qianchen Zeng, Ellen Troyanosky, Noah Kantor, Jianyu Liang, Thomas L. Christiansen

ISBN: 978-1-64353-169-4