FATIGUE STRENGTH OF TWO- AND FOUR-YEAR WEATHERED WELDMENTS OF WEATHERING STEELS AND STRUCTURAL STEEL

Abstract The article discusses the effect of large oxide impurities (a diameter larger than 10 μm in size) on the fatigue resistance of structural steel of high purity during rotary bending. The study was performed on 7 heats produced in an industrial plant. The heats were produced in 140 ton electric furnaces. All heats were desulfurized. The experimental material consisted of semi-finished products of high-grade, carbon structural steel with: manganese, chromium, nickel, molybdenum and boron. Steel sections with a diameter of 18 mm were hardened from austenitizing by 30 minutes in temperature 880°C and tempered at a temperature of 200, 300, 400, 500 and 600°C for 120 minutes and air-cooled. The experimental variants were compared in view of the heat treatment options. Fatigue tests were performed with the use of a rotary bending machine at a frequency of 6000 cpm. The results were statistical processed and presented in graphic form. This paper discusses the results of the relative volume of large impurities, the fatigue strength for various heat processing options.

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Effect of Vibration during Welding on the Fatigue Strength of Structural Steel Weldments

Solid State Phenomena - Advances in Nanomaterials and Processing ◽

10.4028/3-908451-31-0.1329 ◽

2007 ◽

pp. 1329-1332

Author(s):

Chin Hyung Lee ◽

Gab Chul Jang ◽

Hyun Chan Park ◽

Kyong Ho Chang

Keyword(s):

Fatigue Strength ◽

Structural Steel

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Influence of HAZ microstructure and stress concentration on fatigue strength of welded structural steel

Materials Letters ◽

10.1016/0167-577x(94)90252-6 ◽

1994 ◽

Vol 21 (5-6) ◽

pp. 415-423 ◽

Cited By ~ 4

Author(s):

Abdel-Monem El-Batahgy

Keyword(s):

Fatigue Strength ◽

Stress Concentration ◽

Structural Steel

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Multiaxial fatigue strength of common structural steel and the response of some estimation methods

International Journal of Fatigue ◽

10.1016/j.ijfatigue.2017.07.001 ◽

2017 ◽

Vol 104 ◽

pp. 27-42 ◽

Cited By ~ 11

Author(s):

Jan Papuga ◽

František Fojtík

Keyword(s):

Fatigue Strength ◽

Structural Steel ◽

Multiaxial Fatigue ◽

Estimation Methods

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Effect of Fine-Grained Microstructure Induced by Induction-Heating Fine Particle Peening Treatment on Fatigue Properties of Structural Steel (0.45%C)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.891-892.1482 ◽

2014 ◽

Vol 891-892 ◽

pp. 1482-1487

Author(s):

Kazue Murai ◽

Ryota Toyama ◽

Jun Komotori ◽

Kengo Fukazawa ◽

Yoshitaka Misaka ◽

...

Keyword(s):

Residual Stress ◽

Fatigue Strength ◽

Structural Steel ◽

Grain Refinement ◽

Induction Heating ◽

Fine Particle ◽

Optical Microscope ◽

Treatment Temperature ◽

Fatigue Properties ◽

Fine Grained

To improve the fatigue properties of structural steel, a novel surface modification process which combines high-frequency induction heating (IH) with fine particle peening (FPP) was developed. IH-FPP treatment was performed on the surface of structural steel specimens (0.45%C) at temperatures from 600 to 750 °C, with peening times of 60 and 120 s. To determine the characteristics of the treated surfaces, the microstructure was observed using an optical microscope and a scanning electron microscope. Vickers hardness and residual stress distributions were also measured. The characteristics of fine-grained microstructures were examined by electron backscatter diffraction. Furthermore, in order to investigate the effect of the grain refinement achieved by IH-FPP treatment, rotational bending fatigue tests were performed on treated specimens. Results showed that IH-FPP treatment created fine-grained microstructures beneath the surfaces of steel samples. The average ferrite grain size was 4.06 μm for a treatment temperature of 700 °C, and finally 0.76 μm for 600 °C . This was due to dynamic recrystallization in the processed region. IH-FPP treated specimens exhibited a higher fatigue strength than untreated specimens. As almost no compressive residual stress was measured in the treated or untreated specimens, the increase in fatigue strength resulting from IH-FPP treatment was due solely to grain refinement.

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