scholarly journals Microstructure and Fatigue Behavior of 2205/316L Stainless Steel Dissimilar Welded Joints

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 93
Author(s):  
Saúl Leonardo Hernández-Trujillo ◽  
Victor Hugo Lopez-Morelos ◽  
Marco Arturo García-Rentería ◽  
Rafael García-Hernández ◽  
Alberto Ruiz ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Welded Joints ◽  
316L Stainless Steel ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Base Material ◽  
Fatigue Tests ◽  
Solidification Mode ◽  
Tension And Compression ◽  
Weld Toe

The relation among microstructure and fatigue behavior of 2205/316L stainless steel dissimilar welded joints was investigated. Plates of 6.35 mm in thickness with a single-V joint configuration were gas metal arc welded (GMAW) in a single pass by feeding at 6 m/min an ER2209 filler wire with a heat input of 1.2 kJ/mm. Grain growth in the high temperature-heat affected zone (HT-HAZ) occurred mostly at the mid-height of the plates, delimiting the width of this region up to ~1.28 and ~0.73 mm of the 2205 and 316L plates, respectively. Dilution of the 316L plate with the ER2209 filler altered the solidification mode in this side of the weld and led to a significant content of austenite along the fusion line. Fatigue tests were performed using sinusoidal waveform at room temperature applying uniaxial cyclic loading, between constant stress limits within the elastic deformation of tension and compression (Δσ) with stress ratio R = −0.3. With stress ranges of 98% and 95% the fatigue specimens rapidly failed in much less than 106 cycles. The failure crack initiated at the surface of the 316L in the HT-HAZ near the weld toe. Surface analyses of unbroken specimens before and after fatigue testing revealed a significant increment in roughness of the 316L base material owing to the formation of intrusions and extrusions.

Effect of Weld Geometry on the Fatigue Behaviour of Umbilical Super Duplex Stainless Steel Tubes

2017 ◽  
Author(s):  
Hauwa Raji ◽  
Jamie Fletcher Woods
Keyword(s):  
Stainless Steel ◽  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Super Duplex Stainless Steel ◽  
Steel Tubes ◽  
Weld Geometry ◽  
Weld Profile ◽  
Weld Toe ◽  
Toe Angle

The fatigue behavior of welded components is complicated by many factors intrinsic to the nature of welded joints. The mechanical properties of the material, the welding process and position, the type and geometry of the weld and the residual stress distribution across the weld are a few factors affecting fatigue behavior. Published studies [1, 2] have shown that weld geometry is significantly important in determining the fatigue strength of the weld. For a given weld geometry, the fatigue strength is determined by the severity of the stress concentration at the weld toe or at weld defects and by the soundness of the weld metal. The effect of external weld geometry profile on the fatigue behavior of welded small bore super duplex umbilical steel tubes is investigated. Root cause analysis consisting of fractography, metallography and weld profile measurement is carried out on pairs of fatigue failure samples which were tested at the same stress range but failed at significantly different number of cycles. The samples are selected from Technip Umbilicals Ltd (TU) fatigue database. Following the failure analysis, weld geometric profile measurements are performed on fatigue test samples that were prepared for testing. The weld profile was measured in terms of the external weld cap height, weld width and external linear misalignment. Axial fatigue tests are carried out on these samples which are pre-strained before test to simulate the plastic bending cycles typically experienced during the manufacturing and installation processes prior to operational service. The fatigue tests results are interrogated together with the measured geometric data to identify trends and anomalies. Key weld geometric fatigue performance criteria are subsequently identified. For the welded super duplex stainless steel (SDSS) tubes studied, the height of the weld and the weld toe angle provided the best correlation with fatigue life — shorter lives were obtained from specimens with the highest weld aspect ratio (weld height to width) and lowest weld toe angle.

scholarly journals Effects of Surface Softening on the Mechanical Properties of an AISI 316L Stainless Steel under Cyclic Loading

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1788
Author(s):  
Tiehui Fang ◽  
Feng Cai
Keyword(s):  
Stainless Steel ◽  
316L Stainless Steel ◽  
Stress Amplitude ◽  
Fatigue Behavior ◽  
High Stress ◽  
Sample Surface ◽  
Fatigue Tests ◽  
Aisi 316L ◽  
Homogeneous Sample ◽  
Aisi 316L Stainless Steel

The effects of surface softening on fatigue behavior of AISI 316L stainless steel were investigated. Using cold-rolling and electromagnetic induction heating treatment, a gradient structure was fabricated on AISI 316L stainless steel within which the grain size decreased exponentially from micrometers to nanometers to mimic the surface softening. Stress-controlled fatigue tests were applied to both the gradient and homogeneous structures. Compared with the homogeneous sample, surface softening had no evident effect on fatigue behavior when the stress amplitude was greater than 400 MPa, but significantly deteriorated the fatigue behavior at stress amplitude ≤400 MPa. At high-stress amplitude, fatigue behavior is dominated by crack propagation. When the stress amplitude is lowered, strength reduction and stress concentration caused by surface softening accelerate crack initiation and propagation, resulting in an inferior fatigue behavior.

Fatigue Behavior Analysis of Cruciform Welded Joints by Infrared Thermographic Method

2011 ◽  
Vol 197-198 ◽  
pp. 1395-1399 ◽  
Author(s):  
Xing Lin Guo ◽  
Jun Ling Fan ◽  
Yan Guang Zhao
Keyword(s):  
Stainless Steel ◽  
Fatigue Limit ◽  
Welded Joints ◽  
Traditional Method ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Structural Components ◽  
Structural Evaluation ◽  
Fatigue Characteristics ◽  
Good Agreement

Fatigue tests were carried out at different stress levels on cruciform welded joints made from mastensitic stainless steel. The purpose of the present paper was to verify the validity of the thermographic method and to extend its capability on welded structural evaluation, considering the real operating situations. Due to limitations of the traditional fatigue test, the infrared thermographic technique was developed to predict and assess the fatigue limit and the entire S-N (Stress-Life) curve of cruciform welded joints. Through the comparison, the predictions of the fatigue behavior by the thermographic method (TM) manifested good agreement with the traditional method. The present research paper concludes that the TM as a promising method enables us to rapidly obtain reliable fatigue characteristics of welded structural components.

Corrosion fatigue behavior of Al-5Mg coated AISI 316L stainless steel in sodium chloride environments under bending load

2019 ◽  
Vol 66 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Mustafa Öcal ◽  
Recep Sadeler
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
316L Stainless Steel ◽  
Fatigue Behavior ◽  
Base Material ◽  
Ambient Air ◽  
Aisi 316L ◽  
Aisi 316L Stainless Steel ◽  
Content Type ◽  
Bending Load

Purpose The purpose of this study is to describe the environmentally assisted cracking (EAC) of AISI 316L stainless steel as bare and coated cases in several corrosion environments. The main purpose of this study is to extend the lifespan of 316L material under corrosive fatigue in sodium chloride environments. Design/methodology/approach Fatigue tests carried out by using a Schenk type plane bending fatigue machine made by Tokyokoki Co. A scanning electron microscope (SEM) was used to observe the fracture surfaces and tested specimen surfaces. The micro-Vickers hardness of specimens was measured by using a PC-controlled Buehler–Omnimet tester. Findings Under reciprocating bending condition (R = −1) the behavior of 316L SS bare samples and 316L SS coated with Al-5%Mg samples were investigated comparatively at room temperature in ambient air and in several corrosion solutions. The results obtained from the data showed that Al-5Mg coating procedure significantly stabilized the 316L SS even in the most aggressive environment 5 per cent NaCl solution as compared with bare samples. Originality/value Al-5Mg coating showed a stable structure under the corrosion liquids used in the experiments. The coating material served as a stable barrier between the base material and the corrosion fluid, thus ensuring a tightness even in long-term tests below the endurance limit.

Low Cycle Tension-Tension Fatigue Properties of 316L Stainless Steel Thin Sheets

2011 ◽  
Vol 138-139 ◽  
pp. 832-835
Author(s):  
Yong Jie Liu ◽  
Qing Yuan Wang ◽  
Ren Hui Tian ◽  
Xiao Zhao
Keyword(s):  
Stainless Steel ◽  
Room Temperature ◽  
316L Stainless Steel ◽  
Fatigue Testing ◽  
Fatigue Properties ◽  
Loading Frequency ◽  
Thin Sheets ◽  
Effect Factor ◽  
Mechanical Fatigue ◽  
Tensile Fatigue

In this paper, tensile fatigue properties of 316L stainless steel thin sheets with a thickness of 0.1 mm are studied. The tests are implemented by using micro mechanical fatigue testing sysytem (MMT-250N) at room temperature under tension-tension cyclic loading. The S-N curve of the thin sheets descends continuously at low cycle region. Cyclic σ-N curve and ε-N curve are obtained according to the classical macroscopical fatigue theory. The results agree well with the experimental fatigue data, showing that the traditional fatigue research methods are also suitable for description of MEMS fatigue in a certain extent. The effect factor of frequency was considered in this study and the results show that the fatiuge life and the fatigue strength are increased as loading frequency increasing.

Gigacycle Fatigue of Welded Joints of Structural Materials (A Review)

2016 ◽  
Vol 17 ◽  
pp. 14-30 ◽  
Author(s):  
Okechukwu P. Nwachukwu ◽  
Alexander V. Gridasov ◽  
Ekaterina A. Gridasova
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Testing Machine ◽  
Structural Materials ◽  
Fatigue Tests ◽  
Material Defects ◽  
Graphite Cast Iron ◽  
Ultrasonic Fatigue ◽  
Materials Used ◽  
Fatigue Failures

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.

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