Influence of Parent Metal Strength on the Fatigue Strength of Parent Material with Machined and Thermally Cut Edges

The effect of oscillating movement amplitude and frequency of electrode wire swinging on forming of pad weld runs, the character of parent metal penetration, as well as structural and chemical inhomogeneityin the zone of intermixing padding weld with parent material has beentested while submerged arc surfacing using oscillating electrode. It has been stated that along with increasing frequency of electrode wire end oscillations and the same amplitude and surfacing speed, the weld runformation is improved, the width of the zone of padding weld intermixture with parent material is reduced and more dispersive structure with lower structural and chemical inhomogeneity in a padding weld is be- ing formed. More uniform fusion penetration into the parent material and alignment of fusion line can be observed. Those relations remain practically unchanged with increasing amplitude of oscillation.

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An Experimental Study on the Fatigue of Structural Steels with Various Welding Details

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.385-387.593 ◽

2008 ◽

Vol 385-387 ◽

pp. 593-596

Author(s):

Byeong Choon Goo

Keyword(s):

Experimental Data ◽

Fatigue Strength ◽

Structural Steel ◽

Fatigue Tests ◽

Structural Steels ◽

Parent Material ◽

Key Characteristics ◽

Load Carrying ◽

Weld Toe ◽

Ground Load

A structural steel should satisfy various properties under varied conditions. Fatigue strength is one of them. When structural steels are used in the form of welded joints, fatigue strength is one of the key characteristics that should be considered. In this study, comprehensive fatigue tests of a structural steel with yielding strength of about 350 MPa and tensile strength of about 520 MPa were carried out. First, a lot of specimens: parent material plates, butt welded specimens with reinforcement removed, as-welded plates, plates with weld toe ground, load-carrying cruciform, non load-carrying cruciform, plates with transverse fillet welded rib, etc were prepared and tested. S-N curves for the above specimens were compared and analyzed. Secondly, some life-size rectangular beams were fabricated by welding and tested. It is found that annealing is detrimental to fatigue strength rather than beneficial. The experimental data and results may be used usefully by engineers.

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Fatigue strength of normal and high strength steel joints improved by weld profiling

10.31224/osf.io/q4rtx ◽

2021 ◽

Author(s):

Moritz Braun ◽

Jonas Hensel ◽

Shi Song ◽

Sören Ehlers

Keyword(s):

Fatigue Strength ◽

High Strength ◽

Parent Material ◽

Smooth Transition ◽

Material Strength ◽

Treatment Techniques ◽

Fatigue Design ◽

Fatigue Strength Improvement ◽

Steel Joints ◽

Strength Improvement

While some post-weld treatment techniques increase the fatigue life mainly due to induced compressive residual stress others are trying to create a smooth transition at weld toes. One of the latter is weld profiling. This study investigates the effect of weld profiling for four different steel types from S355 to S900 including one duplex stainless-steel and performs a comparison with high frequency mechanical impact treatment. The observed fatigue strength improvement is significantly higher than typically assumed for such techniques and comparable to increases observed for HFMI treatment. The fatigue strength further increases with parent material strength and is only slightly below the estimated fatigue strength of the parent material. Finally, fatigue design curves are proposed for weld profiling that include an increasing fatigue strength improvement for higher strength materials, but that are still conservative for low weld quality.

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Increasing the fatigue strength and operational reliability of the critical elements of a steam turbine

Engineering ◽

10.32820/2079-1747-2018-21-91-97 ◽

2018 ◽

Vol 21 ◽

pp. 91-97

Author(s):

T. Fursova ◽

Keyword(s):

Fatigue Strength ◽

Steam Turbine ◽

Operational Reliability ◽

Critical Elements

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STOCHASTIC CALCULATION OF LIFETIME PREDICTION FOR COMPONENTS IN METAL STRUCTURES DUE TO THE GROWTH OF MICRODEFECTS

Cherepovets State University Bulletin ◽

10.23859/1994-0637-2020-4-97-6 ◽

2020 ◽

Vol 4 (97) ◽

pp. 69-76

Author(s):

IGOR N. SILVERSTOV

Keyword(s):

Fatigue Strength ◽

Fracture Mechanics ◽

Stochastic Approach ◽

Fatigue Curve ◽

Probability Of Failure ◽

Lifetime Prediction ◽

Statistical Distributions ◽

Metal Structures

A stochastic approach has been developed to evaluate fatigue strength using elements of the fracture mechanics. The article presents a method for determining the initial parameters of statistical distributions. It also considers the method for constructing a fatigue curve for a component of any size and configuration with any given probability of failure.

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