A comparative evaluation of low-cycle fatigue behavior of type 316LN base metal, 316 weld metal, and 316LN/316 weld joint

1995 ◽  
Vol 26 (5) ◽  
pp. 1207-1219 ◽  
Author(s):  
M. Valsan ◽  
D. Sundararaman ◽  
K. Bhanu Sankara Rao ◽  
S. L. Mannan
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Weld Joint ◽  
Comparative Evaluation ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue

scholarly journals Prediction of the Ultra-Low-Cycle Fatigue Damage of Q345qC Steel and its Weld Joint

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4014 ◽  
Author(s):  
Qin Tian ◽  
Hanqing Zhuge ◽  
Xu Xie
Keyword(s):  
Finite Element ◽  
Crack Initiation ◽  
Plastic Strain ◽  
Weld Metal ◽  
Base Metal ◽  
Weld Joint ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Experimental Values ◽  
Strain Threshold

Based on the continuum damage mechanics model (CDM) for monotonic tension, a new CDM for ultra-low-cycle fatigue (ULCF) is put forward to predict ULCF damage of steel and its weld joint under strong earthquakes. The base metal, heat-affected zone and weld metal of Q345qC steel were considered as research objects, and the uniaxial plastic strain threshold of the CDM model was calibrated via tensile testing combined with finite element analysis of notched round bar specimens. ULCF tests of the base metal and weld specimens were carried out to analyse their fatigue life, fracture life and post-fracture path. Based on the calibrated uniaxial plastic strain threshold, the finite element models of base metal and weld specimens suitable for CDM model were established by ABAQUS. The calibration results of material parameters show that the weld metal has the lowest plastic strain threshold and the largest dispersion coefficient at the plastic strain threshold. Prediction results under cyclic loading with a large strain were compared with experimental values, and results showed that the predicted crack initiation and fracture lives of the base metal and weld specimens are lower than their corresponding experimental values. The predicted errors of crack initiation life and fracture life decrease with increasing strain level. The development law of the damage variable reveals exponential growth combined with a stepped pattern. The CDM model can also accurately predict the number of cycles to initial damage. Taking the results together, the CDM of the ULCF of the base metal and weld specimens could successfully predict post-fracture paths.

scholarly journals Low Cycle Fatigue Properties of Alloy 617 base Metal and Weld Joint at Room Temperature

2014 ◽  
Vol 3 ◽  
pp. 2201-2206 ◽  
Author(s):  
Seon-Jin Kim ◽  
Pil-Ho Choi ◽  
Rando Tungga Dewa ◽  
Woo-Gon Kim ◽  
Min-Hwan Kim
Keyword(s):  
Base Metal ◽  
Weld Joint ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Alloy 617

Low-Cycle Fatigue Properties of Steels and Their Weld Metals

1989 ◽  
Vol 111 (4) ◽  
pp. 431-437 ◽  
Author(s):  
Y. Z. Itoh ◽  
H. Kashiwaya
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Weld Metal ◽  
Arc Welding ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Steel Weld ◽  
Cycle Fatigue ◽  
Weld Metals ◽  
Metal Arc Welding

Completely reversed, strain-controlled, low-cycle fatigue behavior at room temperature is investigated for steels and their weld metals. Weld metal specimens were taken from multi-pass weld metal deposited by shield metal arc welding (SMAW) and gas metal arc welding (GMAW), such that their gage length consisted entirely of the weld metal. Results indicate that there is a trend toward reduction in the low-cycle fatigue life of weld metals as compared with the base metals. In low carbon steel weld metals, the tendency described above is explained in terms of local plastic strain concentration by lack of uniformity of the multi-pass weld metals. The weld metals do not have the same mechanical properties anywhere as confirmed by hardness distribution, and the fatigue crack grows preferentially through the temper softened region in the multi-pass welds. In Type 308 stainless steel weld metals, the ductility reduction causes reductions in low-cycle fatigue life. This study leads to the conclusion that fairly accurate estimates of the low-cycle fatigue life of weld metals can be obtained using Manson’s universal slope method. However, life estimates of the Type 304 stainless steel is difficult due to a lack of ductility caused by a deformation-induced martensitic transformation.

scholarly journals Understanding Low Cycle Fatigue Behavior of Alloy 617 Base Metal and Weldments at 900 °C

Metals ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 178 ◽  
Author(s):  
Rando Dewa ◽  
Seon Kim ◽  
Woo Kim ◽  
Eung Kim
Keyword(s):  
Base Metal ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Alloy 617

Study on Skirt-to-Shell Attachment of Coke Drum by Evaluation of Fatigue Strength of Weld Metal

2011 ◽  
Author(s):  
Yasuhiko Sasaki ◽  
Shinta Niimoto
Keyword(s):  
Fatigue Strength ◽  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Low Cycle Fatigue ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Fatigue Design ◽  
Inner Radius ◽  
Section Viii

A skirt-to-shell attachment of a coke drum experience severe thermal cyclic stresses, which cause failures due to low cycle fatigue. Various skirt attachment designs, therefore, have been proposed and implemented. A design where the skirt is attached by a weld build-up is most commonly used. A design where the skirt is attached to the drum shell by utilizing an integral machined plate or forging has been utilized in several projects. One of the advantages of the integral skirt attachment is that a large inner radius can be formed which allows reducing stress concentration compared with the weld build-up design. This advantage can be confirmed easily by FE-analysis in recent years [1] [2] [3]. Another major advantage of the integral skirt attachment is that the area of highest stress intensity is located at the base metal section, not at the weld metal or the heat affected zone which are generally thought to have lower fatigue strength. The fatigue design curve from ASME Section VIII Division 2 [9] is based on fatigue tests for the base metal. It is necessary to reveal differences of fatigue strength among these metals. This paper describes a comparison of fatigue strength of three metals: i) base metal ii) weld metal iii) heat affected zone provided by the low cycle fatigue test for 1 1/4Cr-1/2Mo materials. Our results indicate that the fatigue life of the base metal is about twice as long as that of the weld metal and about three times as long as the heat affected zone. Accordingly, the integral skirt attachment is more resistant to cracking than its welded counterpart from a fatigue strength viewpoint.

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