High temperature degradation of powder-processed Ni-based superalloy
Journal Title: Materials Engineering - Materialove inzinierstvo (MEMI) - Year 2015, Vol 22, Issue 2
Abstract
The aim of present work is to study the high temperature degradation of the powder-processed polycrystalline superalloy Ni-15Cr-18Co-4Al-3.5Ti-5Mo. This superalloy has been applied as material for grips of a creep machine. The material was exposed at 1100 °C for about 10 days at 10 MPa stress. During the creep test occurred unacceptable creep deformation of grips as well as severe surface oxidation with scales peeling off. Three types of the microstructure were observed in the studied alloy: (i) unexposed state; (ii) heat treated (annealing – 10 min/ 1200 °C) and (iii) after using as a part of the equipment of the creep machine during the creep test. It is shown that the microstructure degradation resulting from the revealed γ´ phase fcc Ni3(Al,Ti) particles preferentially created at the grain boundaries of the samples after performing creep tests affects mechanical properties of the alloy and represents a significant contribution to all degradation processes affecting performance and service life of the creep machine grips. Based on investigation and obtained results, the given material is not recommended to be used for grips of creep machine at temperatures above 1000 °C.
Authors and Affiliations
Natália Luptáková, Naděžda Pizúrová, Pavla Roupcová, Petr Dymáček
Keywords
Related Articles
- EP ID EP116805
- DOI -
- Views 108
- Downloads 0
HIGH STRAIN RATE BEHAVIOUR OF AN AZ31 + 0.5 Ca MAGNESIUM ALLOY
The paper reports behaviour of magnesium alloy AZ31 (nominal composition 3 % Al - 1 % Zn – balance Mg) with an addition of 0.5 wt. % Ca at high strain rates. Samples were prepared by the squeeze cast technology. Dynamic...
[sub][/sub][sub][/sub]PROPERTIES OF PLASMA AND HVOF SPRAYED COATINGS
The article compares the properties of plasma and HVOF thermally sprayed coatings obtained by blending the NiCrBSi and Fe2O3 powders. The deposition was performed by means of the Plancer PN-120 and the Diamond Jet guns f...
STRUCTURAL STABILITY OF HIGH NITROGEN AUSTENITIC STAINLESS STEEL
This paper deals with the structural stability of an austenitic stainless steel with high nitrogen content. The investigated steel was heat treated at 800°C using different annealing times. Investigation was carried out...
STRUCTURAL CHARACTERISTICS & DIELECTRIC PROPERTIES OF TANTALUM OXIDE DOPED BARIUM TITANATE BASED MATERIALS
In this research, the causal relationship between the dielectric properties and the structural characteristics of 0.5 & 1.0 mole % Ta2O5 doped BaTiO[sub]3[/sub] based ceramic materials were investigated under differe...
INFLUENCE OF GRAIN SIZE ON DUCTILITY OF MAGNESIUM ALLOYS
The paper give a brief overview on the effect of grain size on the yield strength and the elongation to fracture (ductility) of magnesium alloys. The yield stress, flow stress and fracture stress decrese with decreasing...