On the conjoint influence of broaching and heat treatment on bending fatigue behavior of Inconel 718

2016 ◽  
Vol 671 ◽  
pp. 158-169 ◽  
Author(s):  
Zhe Chen ◽  
Johan J. Moverare ◽  
Ru Lin Peng ◽  
Sten Johansson ◽  
David Gustafsson
Keyword(s):  
Heat Treatment ◽  
Inconel 718 ◽  
Fatigue Behavior ◽  
Bending Fatigue

Heat treatment effect on fatigue behavior of 3D-printed maraging steels

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tugce Tezel ◽  
Volkan Kovan
Keyword(s):  
Heat Treatment ◽  
Fatigue Test ◽  
Fatigue Behavior ◽  
Content Type ◽  
Bending Fatigue ◽  
Maraging Steels ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Service Conditions

Purpose This study aims to reveal that fatigue life is improved using heat treatment in the rotational bending fatigue test, which determines the fatigue behavior closest to service conditions. Design/methodology/approach It is essential to know the mechanical behavior of the parts produced by additive manufacturing under service conditions. In general, axial stress and plane bending tests are used by many researchers because they are practical: the service conditions cannot be sufficiently stimulated. For this reason, the rotating bending fatigue test, which represents the conditions closest to the service conditions of a load-bearing machine element, was chosen for the study. In this study, the rotational bending fatigue behavior of X3NiCoMoTi18-9–5 (MS1) maraging steel specimens produced by the selective laser melting (SLM) technique was experimentally investigated under various heat treatments conditions. Findings As a result of the study, MS1 produced by additive manufacturing is a material suitable for heat treatment that has enabled the heat treatment to affect fatigue strength positively. Cracks generally initiate from the outer surface of the sample. Fabrication defects have been determined to cause all cracks on the sample surface or regions close to the surface. Research limitations/implications While producing the test sample, printing was vertical to the print bed, and various heat treatments were applied. The rotating bending fatigue test was performed on four sample groups comprising as-fabricated, age-treated, solution-treated and solution + age-treated conditions. Originality/value Most literature studies have focused on the axial fatigue strength, printing orientation and heat treatment of maraging steels produced with Direct Metal Laser Sintering (DMLS); many studies have also investigated crack propagation behaviors. There are few studies in the literature covering conditions of rotating bending fatigue. However, the rotating bending loading state is the service condition closest to modern machine element operating conditions. To fill this gap in the literature, the rotating bending fatigue behavior of the alloy, which was maraging steel (X3NiCoMoTi18-9–5, 1.2709) produced by SLM, was investigated under a variety of heat treatment conditions in this study.

scholarly journals Influence of Heat Treatment on Cyclic Response of Nickel-Based Superalloy Inconel 718 up to Very-High Cycle Regime

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5358
Author(s):  
Mengxiong Zhao ◽  
Zhenhua Zhao ◽  
Lulu Liu ◽  
Gang Luo ◽  
Wei Chen
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Crack Initiation ◽  
Inconel 718 ◽  
Fatigue Behavior ◽  
Initiation Mechanism ◽  
Cyclic Response ◽  
Self Heating ◽  
Average Grain Size ◽  
Very High

Cyclic response and fatigue behavior are sensitive to the microstructure of material induced by heat treatment. In this paper, three sets of high-temperature superalloy Inconel 718 with different heat treatment, namely annealed, aged, and directly aged high quality (DAHQ), are compared. Difference in grain size distribution, phase, and precipitate, etc., were investigated using an optical camera and scanning electron microscopy. Yield and ultimate strength were found to increase obviously after aging heat treatment. Self-heating phenomenon at 20 kHz was attenuated as grain size decreased. There was a transition from cyclic hardening to softening. Very-high cycle fatigue (VHCF) behavior of Inconel 718 was tested using an ultrasonic fatigue device. Crack initiation duration occupied greater than 99% of the total fatigue life. It concluded that average grain size influences VHCF strength and crack initiation mechanism, and that self-heating phenomenon is not a decisive factor on VHCF strength for Inconel 718.

scholarly journals Bending Fatigue Behavior of 17-4 PH Gears Produced by Additive Manufacturing

2021 ◽  
Vol 11 (7) ◽  
pp. 3019
Author(s):  
Franco Concli ◽  
Luca Bonaiti ◽  
Riccardo Gerosa ◽  
Luca Cortese ◽  
Filippo Nalli ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Specific Resistance ◽  
Fatigue Behavior ◽  
Powder Bed ◽  
Bending Fatigue ◽  
Experimental Campaign ◽  
Single Tooth ◽  
Final Failure ◽  
Effective Design ◽  
Resistance Data

The introduction of Additive Manufacturing (AM) is changing the way in which components and machines can be designed and manufactured. Within this context, designers are taking advantage of the possibilities of producing parts via the addition of material, defining strategies, and exploring alternative design or optimization solutions (i.e., nonviable using subtractive technologies) of critical parts (e.g., gears and shafts). However, a safe and effective design requires specific resistance data that, due to the intrinsic modernity of additive technologies, are not always present in the literature. This paper presents the results of an experimental campaign performed on gear-samples made by 17-4 PH and produced via Laser Powder Bed Fusion (PBF-LB/M). The tests were executed using the Single Tooth Bending Fatigue (STBF) approach on a mechanical pulsator. The fatigue limit was determined using two different statistical approaches according to Dixon and Little. The obtained data were compared to those reported in the ISO standard for steels of similar performance. Additional analyses, i.e., Scanning Electron Microscopy SEM, were carried out to provide a further insight of the behavior 17-4PH AM material and in order to investigate the presence of possible defects in the tested gears, responsible for the final failure.

scholarly journals Effect of Heat Treatment Process on Microstructure and Fatigue Behavior of a Nickel-Base Superalloy

Materials ◽  
2015 ◽  
Vol 8 (9) ◽  
pp. 6179-6194 ◽  
Author(s):  
Peng Zhang ◽  
Qiang Zhu ◽  
Gang Chen ◽  
Heyong Qin ◽  
Chuanjie Wang
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Fatigue Behavior ◽  
Nickel Base Superalloy ◽  
Heat Treatment Process ◽  
Nickel Base ◽  
Base Superalloy

scholarly journals Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 266
Author(s):  
Wakshum M. Tucho ◽  
Vidar Hansen
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Additive Manufacturing ◽  
Inconel 718 ◽  
Solution Heat Treatment ◽  
Hold Time ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Annealing Twins ◽  
Complete Recrystallization

The widely adopted temperature for solid solution heat treatment (ST) for the conventionally fabricated Inconel 718 is 1100 °C for a hold time of 1 h or less. This ST scheme is, however, not enough to dissolve Laves and annihilate dislocations completely in samples fabricated with Laser metal powder bed fusion (L-PBF) additive manufacturing (AM)-Inconel 718. Despite this, the highest hardness obtained after aging for ST temperatures (970–1250 °C) is at 1100 °C/1 as we have ascertained in our previous studies. The unreleased residual stresses in the retained lattice defects potentially affect other properties of the material. Hence, this work aims to investigate if a longer hold time of ST at 1100 °C will lead to complete recrystallization while maintaining the hardness after aging or not. For this study, L-PBF-Inconel 718 samples were ST at 1100 °C at various hold times (1, 3, 6, 9, 16, or 24 h) and aged to study the effects on microstructure and hardness. In addition, a sample was directly aged to study the effects of bypassing ST. The samples (ST and aged) gain hardness by 43–49%. The high density of annealing twins evolved during 3 h of ST and only slightly varies for longer ST.

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