scholarly journals The Influence of Magnetic Field on Fatigue and Mechanical Properties of a 35CrMo Steel

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 542
Author(s):  
Qing Gu ◽  
Xiaxu Huang ◽  
Jiangtao Xi ◽  
Zhenfeng Gao

The influence of a magnetic field of 1.2–1.3 T on the variation of the fatigue behaviors and the mechanical properties of a 35CrMo steel after fatigue tests are investigated in this paper, in order to provide a basic guidance on the application in the similar environment of electrical machinery or vehicles. The microstructures of samples tested with and without magnetic fields are observed and analyzed by XRD, SEM, and TEM techniques. The fatigue life cycles are slightly increased by about 10–15% under magnetic field of 1.2–1.3 T according to the experimental results. A small increment of yield strength under fatigue life cycles of 10,000, 50,000, and 100,000 times is caused by the magnetic field, although the enhancement is only of 5–8 MPa. The dislocation density of the specimen is increased and the uniformity of dislocations is improved by magnetic fields applied during fatigue tests under the same load and cycles. The formation of micro-defects or micro-cracks will be postponed by the improvement in homogeneity of the material, leading to the increase of mechanical properties. The strengthening mechanisms such as deformation hardening and dislocation hardening effects are enhanced by the dislocation entangled structures and the higher density caused by magnetic field.

2018 ◽  
Vol 165 ◽  
pp. 21002 ◽  
Author(s):  
Antonio J. Abdalla ◽  
Douglas Santos ◽  
Getúlio Vasconcelos ◽  
Vladimir H. Baggio-Scheid ◽  
Deivid F. Silva

In this work 300M steel samples is used. This high-strength steel is used in aeronautic and aerospace industry and other structural applications. Initially the 300 M steel sample was submitted to a heat treatment to obtain a bainític structure. It was heated at 850 °C for 30 minutes and after that, cooled at 300 °C for 60 minutes. Afterwards two types of surface treatments have been employed: (a) using low-power laser CO2 (125 W) for introducing carbon into the surface and (b) plasma nitriding at a temperature of 500° C for 3 hours. After surface treatment, the metallographic preparation was carried out and the observations with optical and electronic microscopy have been made. The analysis of the coating showed an increase in the hardness of layer formed on the surface, mainly, among the nitriding layers. The mechanical properties were analyzed using tensile and fatigue tests. The results showed that the mechanical properties in tensile tests were strongly affected by the bainitic microstructure. The steel that received the nitriding surface by plasma treatment showed better fatigue behavior. The results are very promising because the layer formed on steel surface, in addition to improving the fatigue life, still improves protection against corrosion and wear.


2014 ◽  
Vol 790-791 ◽  
pp. 384-389
Author(s):  
Dirk Räbiger ◽  
Bernd Willers ◽  
Sven Eckert

This paper presents an experimental study which in a first stage is focused on obtaining quantitative information about the isothermal flow field exposed to various magnetic field configurations. Melt stirring has been realized by utilizing a rotating magnetic field. In a second step directional solidification of AlSi7 alloys from a water-cooled copper chill was carried out to verifythe effect of a certain flow field on the solidification process and on the resulting mechanical properties. The solidified structure was reviewed in comparison to an unaffected solidified ingot. Measurements of the phase distribution, the grain size, the hardness and the tensile strength were realized. Our results demonstrate the potential of magnetic fields to control the grain size, the formation of segregation freckles and the mechanical properties. In particular, time–modulated rotating fields show their capability to homogenize both the grain size distribution and the corresponding mechanical properties.


2014 ◽  
Vol 891-892 ◽  
pp. 1519-1524 ◽  
Author(s):  
Qian Chu Liu ◽  
Joe Elambasseril ◽  
Shou Jin Sun ◽  
Martin Leary ◽  
Milan Brandt ◽  
...  

Additive Manufacturing (AM) technologies are considered revolutionary because they could fundamentally change the way products are designed. Selective Laser Melting (SLM) is a metal based AM process with significant and growing potential for the manufacture of aerospace components. Traditionally a material needs to be listed in the Metallic Materials Properties Development and Standardization (MMPDS) handbook if it is to be considered certified. However, this requires a considerable amount of test data to be generated on the materials mechanical properties. Therefore, the MMPDS certification process does not lend itself easily to the certification of AM components as the final component can have similar mechanical properties to wrought alloys combined with the defects associated with traditional casting and welding technologies. These defects can substantially decrease the fatigue life of a fabricated component. The primary purpose of this investigation was to study the fatigue behaviour of as-built Ti-6Al-4V (Ti64) samples. Fatigue tests were performed on the Ti-6Al-4V specimens built using SLM with a variety of layer thicknesses and build (vertical or horizontal) directions. Fractography revealed the presence of a range of manufacturing defects located at or near the surface of the specimens. The experimental results indicated that Lack-of-Fusion (LOF) defects were primarily responsible for fatigue crack initiation. The reduction in fatigue life appeared to be affected by the location, size and shape of the LOF defect.


2020 ◽  
Vol 87 (8) ◽  
Author(s):  
Ali Shademani ◽  
Mu Chiao

Abstract Magnetic elastomers (MEs) respond to an applied magnetic field through magnetomechanical coupling, where the mechanical properties of the MEs change with magnetic field strength. These phenomena have been mostly studied under homogenous magnetic fields due to the simplicity. In this work, the effects of the magnetic field gradient on the mechanical properties and the response of the MEs was examined. MEs are made by embedding carbonyl iron microparticles (CI) into a polydimethylsiloxane (PDMS) matrix, which is later rendered porous. The influence of the CI concentration was investigated by manipulating four different samples with CI/PDMS weight ratios of 0.2, 0.6, 1.0, and 1.4. An analytical method was proposed to further understand the interactions of the magnetic field gradient and the material’s response. The proposed theory was later verified with experimental results from compression tests in the presence of different magnetic fields. The proposed theoretical framework and experimental methods can be used to improve the design of MEs in the future.


2013 ◽  
Vol 690-693 ◽  
pp. 2107-2111
Author(s):  
Cheng Wang ◽  
Zhi Lin Lai ◽  
Dong Sun ◽  
Liu Cheng Zhou ◽  
Zhi Bin An

The mechanical properties of 1Cr11Ni2W2MoV stainless steel after laser peening (LP) and ultrasonic shot peening (USP) were examined and compared. The stainless steel specimens were treated with the two different surface processing techniques. X-ray diffractometry (XRD), scanning electron microscope (SEM), microhardness tester were used to investigate microstructure and mechanical properties. Vibration fatigue tests of untreated, LPed and USPed samples were also conducted. The results indicated that LP treatment can improved the fatigue life of 1Cr11Ni2W2MoV stainless steel more effectively. The increases of the compressive residual stress depth and microhardness in surface layer after LP were greater than that of USP. The SEM studies showed that USP treatment had an advantage in microstructure refinement. The compressive residual stresses make great contributions to the superiority of LP in the improvement of fatigue life of 1Cr11Ni2W2MoV stainless steel to USP.


2018 ◽  
Vol 21 (1) ◽  
pp. 141 ◽  
Author(s):  
Hussain J. M. Alalkawi ◽  
Aseel A. Alhamdany ◽  
Marib R. Abdul Hassan

Improving fatigue life is one of the most important issues in mechanical design; an investigation has been conducted on Al 2017-T4. Group of samples have been machined and prepared, some of specimens have been treated using the ultrasonic impact treatment (UIT) with one line peening. The fatigue tests were carried out under constant and variable amplitude (R=-1) at ambient temperature, in order to find out the fatigue life S-N curve and strength after treatment. It has been found significant increasing in strength after it was treated by (UIT).  The fatigue strength is improved after treatment up to 4.16% at 107 cycles, enhancement are present with 24% and 18.78% for the cumulative fatigue lives low-high and high–low respectively.  These results also show a strong tendency of increasing of fatigue strength after application of (UIT) with increase in mechanical properties of material used.


2014 ◽  
Vol 224 ◽  
pp. 57-62
Author(s):  
Stanisław Mroziński ◽  
Grzegorz Golański ◽  
Jacek Słania

The paper presents the results of research on the microstructure and mechanical properties of 12HMF steel after long-term service. The investigated material was taken from a pipe after service at the temperature of 490°C, steam pressure of 8 MPa and service time of 419 988 hours. Performed research has shown that the 12HMF steel after service was characterized by ferritic-bainitic microstructure without any visible advanced processes of its degradation, a typical microstructure for this grade of steel. The tests of mechanical properties have proved that the examined steel after service was characterized by very low impact strength KV, and yield strength lower than the required minimum. Performed fatigue tests of constant amplitude, as well as the programmed ones, have shown that the investigated steel after service is characterized by cyclic softening without a clear period of stabilization of the parameters of hysteresis loop. Moreover, it has been proved that slight changes in the hysteresis loop parameters, as a function of the number of stress cycles, have a significant influence on the obtained material data used when calculating the life.


2020 ◽  
Vol 25 (2) ◽  
Author(s):  
José Aparecido Granato ◽  
João Antonio Pontes ◽  
Erika Peterson Gonçalves ◽  
Viliam Sinka

ABSTRACT Aluminum and its alloys are widely used in the aeronautics industry due to its high lightness and ductility, and it can add other elements, thus changing its characteristics. Fatigue is the major cause of failure of metal materials due to the dynamic and oscillating stresses of the finished materials. The objective of this work is to evaluate the effect of Shot Peening with coverage percentages 1blasting, 3 blasting and 10 blasting in fatigue life of aluminum alloy AA 7475-T351. Shot Peening is a cold surface treatment used to increase fatigue life of the alloy by inducing residual stresses of compression on the surface of the part. In the Shot Peening process, spherical steel grids of type S230 were used, in which the specimens were subjected to 1blasting, 3 blasting and 10 blasting coverage in two stress levels (42 Ksi and 50 Ksi). The results presented in the fatigue tests and electron scanning (SEM) showed the increase in the mechanical properties of all the samples, and those exposed to 1 blasting and 3 blasting presented better results.


2012 ◽  
Vol 726 ◽  
pp. 133-140 ◽  
Author(s):  
Stanisław Mroziński ◽  
Michał Piotrowski

The paper assessed the impact of the laser welding speed on the strength and fatigue properties of the aluminum layer found in multilayer pipes. The conducted experiment has shown that during the adjustment of the welding speed one has to take into account not only the results of static tests, but also the results of fatigue tests. The impact of the welding speed on fatigue life depends on the level of stress max. This level is slight in the area of the biggest stresses and increases along with the decrease in stresses.


Author(s):  
Sheng Bao ◽  
Zhengye Zhao ◽  
Qiang Luo ◽  
Yibin Gu

Abstract The objective of this research is to explore the correlation between piezomagnetic fields and cyclic loading in X80 pipeline steel. A series of stress-controlled fatigue tests were carried out, and the magnetic field variations were recorded simultaneously during the whole loading process. The results demonstrate that the fatigue life of the investigated steel can be divided into three stages. The reversal points that appear during the loading and unloading processes can be used as new parameters to reflect the fatigue state and estimate the fatigue life.


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