The influence of solution annealing on microstructure and mechanical properties heat-resistant cast Steel HK30 modified by Niobium

  • Alen Delić TTU energetik d.o.o., 75000 Tuzla, Bosnia and Herzegovina
  • Mirsada Oruč University of Zenica, 72000 Zenica, Bosnia and Herzegovina
  • Milenko Rimac University of Zenica, 72000 Zenica, Bosnia and Herzegovina
  • Almaida Gigović-Gekić University of Zenica, 72000 Zenica, Bosnia and Herzegovina
  • Raza Sunulahpašić University of Zenica, 72000 Zenica, Bosnia and Herzegovina
Keywords: heat-resistant cast steel, solution annealing, mechanical properties, carbide

Abstract

In this paper, the room temperature mechanical properties, as well as the microstructure of HK 30 Nb steel, were tested in the initial as-cast and solution annealed condition. Results show that tensile properties after the solution annealing have a slightly lower value than as-cast samples. Microstructural analysis of samples after solution annealing showed dissolution of primary carbides present in the initial as-cast condition. The morphology and composition of carbides were changed during a solution annealing. Analysis of microstructure was done by optical microscopy (OM) and scanning electron microscope (SEM), whereas hardness and tensile tests were performed for characterization of mechanical properties.

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A.Delić: "Research of relations between the microstructure and the properties of the heat resistant austenitic steel HK30 modified by niobium in order to improve the properties at elevated temperatures", Doctoral dissertation, Faculty of Metallurgy and Technology, University of Zenica, 2018, 64-88.

Published
2019-10-16
Section
Technical papers