Influence of Solid Solution Temperature on the Microstructure Evaluation of 15-5PH Stainless Steel for Pipe Organ Rail Rod Applications

Chang Liu, Tian Liu

DOI: https://doi.org/10.64486/m.65.2.6
Online publication date: November 26, 2025

Abstract: This study investigates the effect of solid solution treatment temperature on the microstructure and mechanical properties of 15-5PH stainless steel, with the aim of optimizing its performance for precision mechanical components. Samples were solution-treated at 975 °C, 1000 °C, 1025 °C, and 1050 °C, followed by aging at 480 °C for 1 h. Microstructural observations revealed progressive grain coarsen-ing with increasing solution temperature. Mechanical testing showed that yield and tensile strengths increased with temperature up to 1025 °C, reaching maxi-mum values of 1390 MPa and 1286 MPa, respectively, due to enhanced dissolu-tion of strengthening phases prior to aging. In contrast, ductility and impact ener-gy decreased consistently with increasing temperature; the highest toughness was obtained at 975 °C (35.5 J), while the lowest values occurred at 1050 °C (6.5 J). The optimal combination of strength and ductility was achieved at 1025 °C, indicating this temperature as the most effective solution-treatment condition for the tested steel. These findings provide a basis for selecting heat-treatment parameters to enhance the performance and reliability of components manufactured from 15-5PH stainless steel.

Keywords: pipe organ rail bar machine; 15-5PH stainless steel; microstructure; mechanical properties

This article is published online first and will appear in Metalurgija, Vol. 65, Issue 2 (2026).