Thermal Fatigue Characteristics of Heat-Resisting Stainless Steel for Automotive Exhaust

2007 ◽  
Vol 539-543 ◽  
pp. 4944-4949 ◽  
Author(s):  
Tae Kwon Ha ◽  
Hwan Jin Sung
Keyword(s):  
Thermal Fatigue ◽  
Stainless Steels ◽  
Fatigue Property ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Automotive Exhaust ◽  
Load Relaxation ◽  
Temperature Ranges ◽  
Fatigue Characteristics ◽  
Efficiency And Reliability

Thermal fatigue is a complex phenomenon encountered in materials exposed to cyclically varying temperatures in the presence or absence of external load. Continually increasing working temperature and growing need for greater efficiency and reliability of automotive exhaust require immediate investigation into the thermal fatigue properties especially of high temperature stainless steels. In this study, thermal fatigue properties of 304 and 429EM stainless steels have been evaluated in the temperature ranges of 200-800oC and 200-900oC. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. Thermal fatigue property of STS 304 was superior to that of STS 429EM. Load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property.

scholarly journals Evaluation of Fatigue Characteristics of Aluminum Alloys and Mechanical Components Using Extreme Value Statistics and C-specimens

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1915
Author(s):  
Jungsub Lee ◽  
Sang-Youn Park ◽  
Byoung-Ho Choi
Keyword(s):  
Aluminum Alloys ◽  
Fem Analysis ◽  
Extreme Value ◽  
Fatigue Tests ◽  
Extreme Value Statistics ◽  
Fatigue Properties ◽  
Chemical Compositions ◽  
Cross Sectional ◽  
Fatigue Characteristics ◽  
Mechanical Components

In this study, the fatigue characteristics of aluminum alloys and mechanical components were investigated. To evaluate the effect of forging, fatigue specimens with the same chemical compositions were prepared from billets and forged mechanical components. To evaluate the cleanliness of the aluminum alloys, the cross-sectional area of specimens was observed, and the maximum inclusion sizes were obtained using extreme value statistics. Rotary bending fatigue tests were performed, and the fracture surfaces of the specimens were analyzed. The results show that the forging process not only elevated the fatigue strength but also reduced the scatter of the fatigue life of aluminum alloys. The fatigue characteristics of C-specimens were obtained to develop finite-element method (FEM) models. With the intrinsic fatigue properties and strain–life approach, the FEM analysis results agreed well with the test results.

scholarly journals Using Fatigue Characteristics to Analyse Test Results for 16Mo3 Steel under Tension-Compression and Oscillatory Bending Conditions

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1197 ◽  
Author(s):  
Andrzej Kurek
Keyword(s):  
Compression Test ◽  
Experimental Tests ◽  
Fatigue Tests ◽  
Test Method ◽  
Fatigue Properties ◽  
Test Results ◽  
Bending Tests ◽  
Fatigue Characteristics ◽  
Cost Efficient ◽  
Plastic Components

In this study, 16Mo3 steel was analysed for fatigue tests under tension-compression and oscillatory bending conditions. The analysis involved a comparison of fatigue test results obtained using the Manson-Coffin-Basquin, Langer and Kandil models and the models proposed by Kurek-Łagoda. It was observed that it is possible to substitute the basic tension-compression test performed in large testing machines with oscillatory bending tests carried out on a simple, modern test stand. The tests were performed under oscillatory bending on a prototype machine. The testing of 16Mo3 steel proved that the best-known Mason-Coffin-Basquin fatigue characteristic describes the results of all of the experimental tests very well, but the model can only be used when it is possible to divide strains into elastic and plastic components. It should be emphasised here that there is no such possibility in the case of tests performed under oscillatory bending conditions. It was proven that the proposed test method can substitute the tension-compression test very well and be a much more cost efficient way to obtain LCF material fatigue properties.

The Fatigue Property Research of Steel Q345 Butt Welded Joint

2014 ◽  
Vol 692 ◽  
pp. 424-427
Author(s):  
Wei Ping Ouyang ◽  
Liang Sheng Chen ◽  
Xiu Dong Xu
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Modeling ◽  
Significant Influence ◽  
Welded Joints ◽  
Welded Joint ◽  
Fatigue Property ◽  
Fracture Analysis ◽  
Fatigue Tests ◽  
Fatigue Properties

The fatigue property of the butt welded joint has significant influence to hoisting equipment’s design, manufacture and using safety for its extensive application. This paper conducted a study on the fatigue properties of a series of the most commonly used thickness steel Q345 butt welded joints. Through fatigue tests and fracture analysis, the fatigue pattern and fracture law of the joints were revealed. Combining with the finite element modeling, the all field stress distribution situation was obtained. This has profound reference significance to hoisting machinery research.

Fatigue Properties of Aluminium Alloys for Uniaxial Cyclic Loads

2014 ◽  
Vol 598 ◽  
pp. 13-19
Author(s):  
Ewelina Böhm ◽  
Tadeusz Łagoda
Keyword(s):  
Fatigue Strength ◽  
Chemical Composition ◽  
Aluminium Alloys ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cyclic Loads ◽  
Fatigue Characteristics

The paper presents an analysis of aluminium and its alloys in terms of fatigue strength. The paper contains information in terms of cyclic fatigue tests of aluminium alloys. On the basis of available literature data, Basquin fatigue characteristics have been designated. On their basis a comparison between chosen fatigue characteristics of aluminium alloys with different chemical composition and element percentage in the substance have been done.

Spectra Thermal Fatigue Tests Under Frequency Controlled Fluid Temperature Variation: Superposed Sinusoidal Temperature Fluctuation Tests

2008 ◽  
Author(s):  
Nobuchika Kawasaki ◽  
Hideki Takasho ◽  
Sumio Kobayashi ◽  
Shinichi Hasebe ◽  
Naoto Kasahara
Keyword(s):  
Fatigue Strength ◽  
Crack Initiation ◽  
Thermal Fatigue ◽  
Test Piece ◽  
Fatigue Tests ◽  
Fluid Temperature ◽  
Test Pieces ◽  
Temperature Waves ◽  
Temperature Ranges ◽  
Sinusoidal Temperature

To clarify frequency-dependent attenuation effects of fluid temperature fluctuation on fatigue strength, thermal fatigue strength tests subjected to superposed sinusoidal temperature fluctuations were performed by the SPECTRA test facility. Fluid temperature waves were generated by superposition of sinusoidal waves, where frequencies were 0.05, 0.2, and 0.5Hz. Two types of superposed waves were selected for the tests, dual and triple ones. The dual one was obtained by superposing two sinusoidal waves whose temperature ranges and frequencies are respectively 200 centigrade and 0.05Hz and 60 centigrade and 0.5Hz at the inlet of test piece. The triple one was the superposition of three sinusoidal waves whose temperature ranges and frequencies are respectively, 150 centigrade and 0.2Hz, 75 centigrade and 0.05Hz and 50 centigrade and 0.5Hz at the inlet of test piece. The longest periods were 20 seconds for both types of waves and it is the fundamental cycle for the thermal fatigue tests. For the dual case, 73,810 cycles fatigue test was performed while for the triple one 116,640 cycles were performed. After these fatigue tests, cylindrical test pieces were cut away from the test loop, and cracks were observed on the inner surface of the test pieces. For the dual wave case, crack initiation occurred from 400 to 600mm position from the inlet of test piece. For the triple wave case, crack initiation occurred from 400 to 600mm position from the inlet of test piece. The corresponded fluid temperature range to crack initiation is from 205 to 220 centigrade for the dual one and from 195 to 215 centigrade for the triple one. Fatigue lives at crack initiation positions were evaluated based on the test conditions. Adopting power spectrum density functions and frequency transfer functions, fatigue lives were predicted within a factor 3 as predicted for single sinusoidal temperature waves in the other tests. To confirm advantages of these functions, fatigue life estimations were compared with those obtained without using these functions. Based on the compared results, these functions are necessary to predict accurate fatigue lives.

Effect of Scratch Depths on Fatigue Properties of PMMA for Aircraft Canopies

2014 ◽  
Vol 687-691 ◽  
pp. 81-84 ◽  
Author(s):  
Xin Hong Shi ◽  
Mei Juan Shan
Keyword(s):  
Fatigue Limit ◽  
Polymethyl Methacrylate ◽  
Fatigue Property ◽  
Fatigue Tests ◽  
Experimental Results ◽  
Fatigue Properties ◽  
Scratch Depth

A series of fatigue tests is performed for polymethyl methacrylate (PMMA) specimens without scratches and with scratches. The scratch depth is set to be 0.2mm, 0.3mm and 0.4mm, respectively. Based on the experimental results, it can be deduced that contained fatigue limit of specimens with scratches significantly decreases compared to specimens without scratches. Besides, contained fatigue limit decreases gradually with scratch depth increasing from 0.0mm to 0.4mm. Consequently, it can be concluded that fatigue properties of PMMA will decrease when there exists scratch and for scratch depth from 0.0mm to 0.4mm, fatigue property decreases remarkably with deeper scratch.

Fatigue Properties and Design Criteria of a Gamma Titanium Aluminide Alloy

2011 ◽  
Vol 465 ◽  
pp. 531-534 ◽  
Author(s):  
Stefano Beretta ◽  
Mauro Filippini ◽  
Luca Patriarca ◽  
Giuseppe Pasquero ◽  
Silvia Sabbadini
Keyword(s):  
Titanium Aluminide ◽  
Electron Beam Melting ◽  
Room Temperature ◽  
Tial Alloy ◽  
High Cycle Fatigue ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Gamma Titanium Aluminide ◽  
Titanium Aluminide Alloy ◽  
Fatigue Characteristics

The fatigue properties of a Ti-48Al-2Cr-2Nb alloy obtained by electron beam melting (EBM) with a patented process has been examined by conducting high cycle fatigue tests performed at different loading ratios both at room temperature and at high temperatures, comparable to those experienced by the components during service. Some tests have been conducted in the superlong life regime well exceeding 10 million cycles, highlighting individual fatigue characteristics of the studied TiAl alloy.

Fatigue Properties of Austenitic Stainless Steels with Different Nitrogen

2004 ◽  
Vol 261-263 ◽  
pp. 1215-1220 ◽  
Author(s):  
Nobusuke Hattori ◽  
S. Nishida
Keyword(s):  
Fatigue Strength ◽  
Stainless Steels ◽  
Stress Amplitude ◽  
Austenitic Stainless Steels ◽  
Fatigue Tests ◽  
The Other ◽  
Fatigue Properties ◽  
Transformation Ratio ◽  
Other Hand ◽  
Knee Point

The fatigue properties of austenitic stainless steels become inevitably important when using in structural materials. The authors have performed fatigue tests to investigate the effect of nitrogen content on fatigue properties of typical austenitic stainless steels (SUS304) and two kinds of nitrogen-contained SUS304 (SUS304N and YUS170). The main results obtained in this study are as follows; (1) The knee point in S-N curves exists for SUS304 and SUS304N, but does not exist for YUS170. (2) The fatigue limit of SUS304N is higher than that of SUS304. On the other hand, the fatigue strength by 107 cycles of YUS170 is lower than those of SUS304 and SUS304N. (3) For SUS304, the transformation ratio increases with increase in stress amplitude. On the other hand, the transformation ratio of SUS304N is very small and that of YUS170 remains essentially zero.

Sign in / Sign up

Export Citation Format

Share Document