A Review of Haynes® 230 and Haynes 617 Alloys for High Temperature Gas Cooled Reactors

2007 ◽  
Author(s):  
Michael Katcher ◽  
Dwaine L. Klarstrom
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Grain Boundary ◽  
Creep Strength ◽  
Thermal Fatigue ◽  
Low Cycle Fatigue ◽  
Carbide Precipitation ◽  
Cooling Rates ◽  
High Temperature Gas

HAYNES 230 and 617 alloys are competing for use on Generation IV, high temperature gas cooled reactor components because of their good high temperature creep strength in the temperature range of 760°C and 982°C and resistance to attack in the gas cooled reactor environment. A review of the metallurgy affecting the properties in each alloy is provided. It is shown that the grain size and carbide precipitation developed during manufacture affect short term and long term ductility, fatigue life, and creep strength. For example, 230 alloy has a finer grained structure which promotes fatigue strength with a slight sacrifice in creep strength. The 617 alloy has a coarser grain structure which provides slightly higher creep resistance while sacrificing some fatigue strength. Thermal aging also introduces gamma prime precipitation to 617 alloy in addition to grain boundary carbides. This, along with grain boundary oxidation, reduces the low cycle fatigue strength of 617 alloy compared to 230 alloy. Independent studies have shown that 230 alloy possesses higher resistance to thermal fatigue than 617 alloy. However, welds of both base metals with similar weld composition have about the same thermal fatigue life. Cooling rates from solution annealing temperatures during processing affect the ductility and creep strength of these alloys with the highest cooling rates preferred for retention of ductility and creep strength. Slow cooling rates promote carbide precipitation in the grain boundaries which reduces ductility and creep strength.

A Review of Haynes® 230® and 617 Alloys for High Temperature Gas Cooled Reactors

2008 ◽  
Vol 595-598 ◽  
pp. 511-517 ◽  
Author(s):  
Michael Katcher ◽  
Dwaine L. Klarstrom
Keyword(s):  
High Temperature ◽  
Fatigue Strength ◽  
Grain Boundary ◽  
Creep Strength ◽  
Thermal Fatigue ◽  
Low Cycle Fatigue ◽  
Carbide Precipitation ◽  
Grain Structure ◽  
Cooling Rates ◽  
High Temperature Gas

HAYNES® 230® and 617 alloys are competing for use on Generation IV, high temperature gas cooled reactor components because of good high temperature creep strength in the temperature range between 760°C and 982°C and resistance to oxidation in the gas cooled reactor environment. A review of the metallurgy affecting the properties in each alloy will be discussed. Grain size and carbide precipitation developed during fabrication effect short term and long term ductility, fatigue, and creep. For example, 230 alloy has a finer grained structure which promotes fatigue strength with a slight sacrifice in creep strength. The 617 alloy has a coarser grain structure which provides slightly higher creep resistance while sacrificing some fatigue strength. Thermal aging also introduces gamma prime precipitation to the 617 alloy as well as grain boundary carbides, and this, in addition to grain boundary oxidation, reduces the low cycle fatigue strength of 617 alloy compared to 230 alloy. Independent studies have shown that 230 alloy possesses higher resistance to thermal fatigue than 617 alloy. However, welds of both base metals with similar weld composition have about the same thermal fatigue life. Cooling rates from solution annealing temperatures during processing effect the ductility and creep strength of these alloys with the highest cooling rates preferred for retention of ductility and creep strength. The reason; slow cooling rates promote carbide precipitation in the grain boundaries which reduces ductility and creep strength.

Assessment of Fatigue Life for High-Temperature Pipeline Welds Using X-Ray Diffraction Technique

2007 ◽  
Vol 353-358 ◽  
pp. 130-133
Author(s):  
Keun Bong Yoo ◽  
Jae Hoon Kim
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Power Plants ◽  
Low Cycle Fatigue ◽  
Diffraction Method ◽  
Life Assessment ◽  
Fatigue Properties ◽  
X Ray Diffraction ◽  
X Ray

The objective of this study is to examine the feasibility of the X-ray diffraction method for the fatigue life assessment of high-temperature steel pipes used for main steam pipelines, re-heater pipelines and headers etc. in power plants. In this study, X-ray diffraction tests were performed on the specimens simulated for low cycle fatigue damage, in order to estimate fatigue properties at the various stages of fatigue life. As a result of X-ray diffraction tests, it was confirmed that the full width at the half maximum (FWHM) decreased with an increase in the fatigue life ratio, and that the FWHM and the residual stress due to fatigue damage were algebraically linearly related to the fatigue life ratio. From this relationship, a direct assessment of the remaining fatigue life was feasible.

scholarly journals High Temperature Low-cycle Fatigue Properties and Grain Boundary Configuration in an Austenitic Heat Resisting Steel

1983 ◽  
Vol 69 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Masaru YAMAMOTO ◽  
Yasushi HORIUCHI ◽  
Ohmi MIYAGAWA ◽  
Dai FUJISHIRO
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue

Comparative Study of Microstructure and High Temperature Low Cycle Fatigue Behaviour of Nickel Base Superalloys Inconel 713LC and MAR-M247

2016 ◽  
Vol 713 ◽  
pp. 86-89 ◽  
Author(s):  
Ivo Šulák ◽  
Karel Obrtlík ◽  
Ladislav Čelko
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Strain Curve ◽  
Cyclic Stress ◽  
Fatigue Tests ◽  
Casting Defects ◽  
Cycle Fatigue ◽  
Stress Strain Curve ◽  
Nickel Base

The present work is focused on the study of microstructure and low cycle fatigue behavior of the first generation nickel-base superalloy IN 713LC (low carbon) and its promising second generation successor MAR-M247 HIP (hot isostatic pressing) at 900 °C. Microstructure of both alloys was studied by means of scanning electron microscopy (SEM). The microstructure of both materials is characterized by dendritic grains, carbides and casting defects. Size and morphology of precipitates and casting defects were evaluated. Fractographic observations have been made with the aim to reveal the fatigue crack initiation place and relation to the casting defects and material microstructure. Low cycle fatigue tests were conducted on cylindrical specimens in symmetrical push-pull cycle under strain control with constant total strain amplitude and strain rate at 900 °C in air. Hardening/softening curves, cyclic stress-strain curve and fatigue life data of both materials were obtained. Cyclic stress-strain curve of MAR M247 is shifted approximately to 120 MPa higher stress amplitudes in comparison with IN 713LC. Significantly higher fatigue life of MAR-M247 has been observed in Basquin representation. On the other hand IN 713LC shows prolonged lifetime compared with MAR-M247 in the Coffin-Manson representation. Results obtained from high temperature low cycle fatigue tests are discussed.

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