scholarly journals Testing and calculation of impact fatigue strength of Flap-X and SS 716 flapper valve steel grades

2019 ◽  
Vol 604 ◽  
pp. 012062
Author(s):  
Muhammad Waqas Tofique ◽  
Alexander Löf ◽  
Chris Millward ◽  
Zippl Günther
Keyword(s):  
Fatigue Strength ◽  
Impact Fatigue ◽  
Steel Grades ◽  
Valve Steel

scholarly journals M. W. Tofique, A. Löf, C. Millward, Z. Günther. Testing and calculation of impact fatigue strength of Flap-X and SS 716 flapper valve steel grades / trans from Engl. M. A. Fedorova

2021 ◽  
Vol 5 (3) ◽  
pp. 63-74
Author(s):  
M. A. Fedorova ◽  
Keyword(s):  
Fatigue Strength ◽  
Service Life ◽  
Fluid Pressure ◽  
Test Method ◽  
Impact Fatigue ◽  
Staircase Test ◽  
Reliable Service ◽  
Steel Grades ◽  
Valve Steel ◽  
The Impact

During the operation of reciprocating compressors, the flapper valve opens and closes under fluid pressure and flow. As it closes, it strikes against the valve seat, generating stresses and noise. This cycle of loading produces bending and impact fatigue stresses in the reed. This load pattern is repeated billions of times during the service life of a compressor and it defines the service life and reliability. The goal of this study was to calculate the impact fatigue strength of the Flap-X and the SS 716 grades and, to provide the compressor manufacturers with the information they can use to specify a steel grade to be used in their compressors, for reliable service. Impact fatigue tests were conducted on a custom-built impact fatigue test rig that used air pulses to produce movement of the reed valves manufactured by a major European compressor manufacturer Nidec Global appliance GmbH, at a frequency of 315 Hz and pulse width of 2,2 milliseconds. The testing was conducted according to the staircase test method detailed in the International Standard SS-ISO 12107:2012. The impact fatigue strength of the Flap-X and SS 716 steel valves was calculated in terms of the impact velocity according to the modified staircase test method in the standard. The test results and their statistical analysis showed that the impact fatigue strength of the Flap-X grade was higher compared to the SS 716 grade. The calculation and testing of the impact fatigue strength of the flapper valve steel grades could help the compressor designers to select the optimum material for their compressor designs, to provide reliable service. The higher impact fatigue strength of the Flap-X grade, lower failure rate and longer impact fatigue life will allow the compressor manufacturers to design thinner valves, as Flap-X can sustain higher impact fatigue stresses reliably for longer time and, at the same time help reduce noise, as thinner valves produce less noise for a given pressure and frequency.

Low-cycle impact fatigue strength of steel N18K9M5T with a biphase?+? structure

1981 ◽  
Vol 23 (4) ◽  
pp. 261-265 ◽  
Author(s):  
I. V. Pestov ◽  
A. Ya. Maloletnev ◽  
M. D. Perkas ◽  
A. F. Edneral
Keyword(s):  
Fatigue Strength ◽  
Impact Fatigue ◽  
Steel N18k9m5t ◽  
Biphase Structure

Impact Bending Fatigue Strength of Gear Teeth Case-Hardened by Nitriding and Carburizing

2000 ◽  
Author(s):  
Koji Maenosono ◽  
Akira Ishibashi ◽  
Keiji Sonoda
Keyword(s):  
Fatigue Strength ◽  
Power Transmission ◽  
Plasma Nitriding ◽  
Impact Fatigue ◽  
Gear Teeth ◽  
High Tension ◽  
High Fatigue ◽  
Alloy Steels ◽  
Almost All ◽  
The Impact

Abstract Almost all gears used for power transmission of automobiles have been case-hardened by carburizing. Recently, strict demand for reducing running noise and vibration from the power transmission gears requires, in most cases, an additional finishing operation such as grinding and/or honing after carburizing. Nitriding is conducted at a temperature of about 820 K which is lower than the transformation temperature, and thus quenching is not required, resulting in smaller heat treatment deterioration. However, nitrided gears hardly used in practice as for power transmission gears. In the present investigation, experiments were conducted, using test gears case-hardened by two different methods, carburizing and plasma-nitriding. Test results showed that the fatigue strength of carburized gears was higher than that of nitrided gears in most cases when the test gears were made from the same steel. However, the impact fatigue strengths of nitrided gears made from a high tension steel with additional alloy elements Mo and V were higher than those of carburized gears made from the carbon and alloy steels which have been, used as for gear material. The other high tension steel containing neither Mo nor V could not bring about a sufficiently high fatigue strength in comparison with the conventional carburized gears. It should be noted that the impact fatigue strength of carburized gears made from the high tension steel was higher than the ones made of conventional carburizing steel.

Consideration of Impact Fatigue Strength of Carburized Gears

2005 ◽  
Author(s):  
Naomi Miura ◽  
Takao Hayashi ◽  
Yoshio Okada ◽  
Shinichi Araki ◽  
Takashi Kano ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Impact Fatigue

601 Low Cycle Impact Fatigue Strength of Steel Smooth and Notched Specimens

2012 ◽  
Vol 2012.87 (0) ◽  
pp. _6-1_
Author(s):  
Ryuji TAGUCHI ◽  
Atsushi GONOKUCHI ◽  
Yoshitaka YAMAMOTO ◽  
Hiroaki HASHIMOTO ◽  
Isamu RIKU ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Impact Fatigue ◽  
Notched Specimens

138 An impact fatigue strength characteristics fornotch specimens of carbon steel

2008 ◽  
Vol 2008.43 (0) ◽  
pp. 77-78
Author(s):  
Kyohei YAMASHITA ◽  
Hitoshi WADA ◽  
Iwao KONDO ◽  
Katsuhiko MURASE
Keyword(s):  
Fatigue Strength ◽  
Carbon Steel ◽  
Strength Characteristics ◽  
Impact Fatigue

scholarly journals Comparison of fatigue characteristics of 38ХН3МФА and 40ХН high-tensile-strength steels based on test results

2020 ◽  
Vol 4 (394) ◽  
pp. 63-69
Author(s):  
Semyon D. Knoring ◽  
Victor V. Platonov ◽  
Nikolay G. Popov ◽  
Valery M. Shaposhnikov
Keyword(s):  
Fatigue Strength ◽  
Fresh Water ◽  
Strength Characteristics ◽  
Test Results ◽  
Cyclic Tests ◽  
40Kh Steel ◽  
Notched Specimens ◽  
Steel Grades ◽  
Fatigue Characteristics ◽  
Better Than

Object and purpose of research. The object of work is steel “38ХН3МФА”, planned for use in the propeller shafts manufacture of the lead-ship (project 10510), and less strong steel “40XH”, used in the propeller shafts manufacture for icebreakers of lower ice categories and lower power. The purpose of the study is to compare the fatigue strength of these steel grades. Materials and methods. Investigations of the fatigue strength characteristics of steels were carried out by cyclic tests of flat notched specimens in air and cylindrical specimens in fresh water. Main results. It is shown that lowest fatigue strength results correspond to external cyclic loading of specimens with stress concentrator (notch). But even in these conditions, fatigue strength of 38ХН3МФА steel is better than that of 40XH steel. As for the tests of smooth samples in fresh water, 38ХН3МФА steel also has a clear advantage over 40XH steel. Conclusion. The studies have shown that fatigue strength characteristics of 38ХН3МФА steel in the air and in corrosive environment exceed those of 40XH steel. Environmental sensitivity and stress concentration of 38ХН3МФА steel turned out to be higher than for 40KH steel.

Ermüdung von Schweißverbindungen höher- und hochfester warmgefertigter nahtloser Stahlbauhohlprofile MSH/Fatigue of Welded Connections at Hot Finished Higher Strength or High Strength Hollow Sections

Konstruktion ◽  
2018 ◽  
Vol 70 (01-02) ◽  
pp. 76-81
Author(s):  
Bernd Kranz ◽  
Jörg Herrmann ◽  
Ronny Baum ◽  
Boris Straetmans
Keyword(s):  
Fatigue Strength ◽  
Boundary Conditions ◽  
Fatigue Test ◽  
High Strength Steel ◽  
High Strength ◽  
Machine Construction ◽  
Hollow Section ◽  
Steel Grades ◽  
Additional Reference

Inhalt: Dauerfestigkeit geschweißter Hohlprofilkonstruktionen ist für viele Anwendungen im Maschinenbau relevant. Für Schweißverbindungen höher- und hochfester Hohl- profilwerkstoffe gibt es aber nur eine begrenzte Anzahl verfügbarer Angaben. Ziel der vorliegenden Untersuchung an drei höher- und hochfesten Werkstoffen ist die Ermittlung von Wöhlerlinien bei unterschiedlichen Verarbeitungsrandbedingungen. Konkret wurden dazu konventionelle MSG Schweißverbindungen an bauteilähnlichen Proben ohne und mit Nahtvorbereitung sowie mit Nahtvorbereitung und Vorwärmen hergestellt und Ermüdungsversuchen unterzogen. Konstrukteuren und Verarbeitern dienen diese als weitere Referenz zur optimalen Nutzung der vorgestellten Verbindungen und Werkstoffe.   Abtract: Fatigue strength of welded hollow section designs is relevant for many applications in machine construction. For welded connections of higher strength or high strength hollow sections only a limited amount of data is available. Objective of the present research on three higher strength or high strength steel grades is the determination of Wöhler curves for different boundary conditions for processing. In practice components of conventionally GMAW welded-connections had been manufactured, without weld preparation, with weld preparation and with weld preparation and preheating – subsequently a fatigue test was done. Results serve designers and manufacturers as additional reference for optimized use of the presented joints and steel grades.

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