Microstructure and Mechanical Properties of an Austenitic Heat-Resistant Steel after Service at 570 °C and 25.4 MPa for 18 Years

Abstract

Microstructure and mechanical properties of an austenitic heat-resistant steel (12Cr18Ni12Ti) serviced in a supercritical power plant at 570 °C/25.4 MPa for 160,000 h were investigated. The results show that the hardness and the tensile strength did not decrease; however, the impact toughness was remarkably reduced. The TiC precipitate shows excellent thermostability; for example, it hardly grew up, and no big M23C6 carbides were found. However, large Fe, Cr-rich σ-phase was doomed to precipitate along grain boundary, which should be responsible for the reduced toughness. The growth of σ-phase was observed to have an interaction with the preexisted carbides.

Recent Advancements in Material Waste Recycling: Conventional, Direct Conversion, and Additive Manufacturing Techniques

“…Nickel-based super alloys are used in the development of aircraft exhaust valves and turbine rotors due to their high creep resistance at higher temperatures [12]. Research has been carried out on improving the microstructure and mechanical properties of stainless-steel alloys [13][14][15][16][17][18][19], aluminum alloys [20][21][22][23][24][25][26], titanium alloys [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41], and nickel-based super alloys [42,43] using different techniques like adding carbides [44][45][46][47], alloying elements [48][49][50][51], and heat treatments [20,21,42]. Conventional fabrication involves multiple processes and is time consuming.…”

Influence of Higher Stabilization Temperatures on the Microstructure and Mechanical Properties of Austenitic Stainless Steel 08Ch18N10T

“…Many research papers discuss the heat treatment of stabilized austenitic stainless steels. Publications have very often dealt with the HT of parts after welding [4][5][6][7], corrosion resistance (especially intercrystalline corrosion) [8][9][10][11], fatigue properties [12][13][14], or the mechanical properties of commercial steel AISI321 [15][16][17]. However, what is not very common in the literature is the issue of the HT of stabilized grades in order to increase their mechanical characteristics, especially the cold and hot yield strength (YS) and ultimate tensile strength (UTS) [18].…”