The Evolution and Determination of Mechanical Properties During the Manufacturing Process of High Strength Spirally Welded Pipe

2006 ◽  
Author(s):  
Xiande Chen ◽  
Laurie Collins ◽  
Fathi Hamad ◽  
Dengqi Bai
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Manufacturing Process ◽  
High Strength ◽  
Ring Expansion ◽  
Test Methods ◽  
Pipe Axis ◽  
Seam Welding ◽  
Welded Pipe

During the development of high strength and high toughness spirally welded pipe with improved weld heat affected zone toughness, the evolution of the mechanical properties were studied by testing at different stages of the manufacturing process. The mechanical properties were measured in the as-welded condition after the spiral seam welding, after the hydrostatic test and after the aging cycle simulating the external pipe coating process. The tensile properties of the pipe body in the transverse-to-pipe-axis (TPA) orientation, as required by the CSA Z245.1 and API 5L standards, were determined using different test methods and different specimen geometries, such as flattened strip specimen, non-flattened round-bar specimen and ring-expansion specimen. The investigation results provided some insights into the development of the mechanical properties of the final pipe products and the methods for more realistically and reliably determining the tensile properties of the pipe along the circumferential direction.

ALLEGHENY LUDLUM TYPE 205

Alloy Digest ◽  
1997 ◽  
Vol 46 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Magnetic Permeability ◽  
Cold Working ◽  
High Strength ◽  
Heat Treating ◽  
Austenitic Steels

Abstract Allegheny Stainless Type 205 is a chromium-manganese nitrogen austenitic high strength stainless steel that maintains its low magnetic permeability even after large amounts of cold working. Annealed Type 205 has higher mechanical properties than any of the conventional austenitic steels-and for any given strength level, the ductility of Type 205 is comparable to that of Type 301. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SS-640. Producer or source: Allegheny Ludlum Corporation. Originally published March 1996, revised October 1997.

Application of Small Punch Test to Evaluate Tensile Properties of SA213T22 Grade Boiler Steel

2015 ◽  
Vol 830-831 ◽  
pp. 191-194
Author(s):  
M. Venkateswara Rao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tensile Properties ◽  
Test Methods ◽  
Uniaxial Tensile ◽  
Test Results ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test ◽  
Aging Phenomena

Conventional tensile test methods are used for service exposed high temperature boiler tubes to evaluate the deterioration in mechanical properties such as tensile strength, yield strength and percentage elongation. The mechanical properties are required to be evaluated periodically as the boiler components undergo material degradation due to aging phenomena. The aging phenomena occurs due to continuous exposure of tubes to high temperature & pressure steam prevailing inside the tubes and high temperature exposure to corrosive combustible gases from the external surfaces within the boiler.A recent developed new technique called small punch testing has been used to evaluate the tensile properties of SA 213T22 grade steel predominantly exists in super-heater and re-heater sections of boiler. The small punch tests have been carried out on the miniature disk shaped specimens of diameter of 8.0 mm and 0.5 mm thickness extracted from both the new and service exposed tubes. Conventional uniaxial tensile tests on standard specimens from the same tube material have also been performed for comparison. The service exposed tubes showed considerable loss in mechanical properties in both the conventional and small punch test results. Correlations of tensile properties have been obtained based on the comparative analysis of both small punch and uniaxial tensile test results. Further, the study showed that an appropriate empirical relation could be generated for new and service exposed materials between both the techniques. Conventional test methods require large quantity of material removal for test samples from in-service components whereas small punch test method needs only a miniature sample extraction. This small punch test technique could also be extended to evaluate the thicker section boiler components such as pipelines and headers in the boiler as a part of remaining life assessment study. Also this technique could be a useful tool to any metallic component where large quantity of sample removal may be difficult or may not be feasible.

Microstructural, surface and fatigue analysis of stress peened leaf springs

2015 ◽  
Vol 6 (5) ◽  
pp. 589-604 ◽  
Author(s):  
Georgios Savaidis ◽  
Stylianos Karditsas ◽  
Alexander Savaidis ◽  
Roselita Fragoudakis
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fatigue Life ◽  
Manufacturing Process ◽  
Treatment Process ◽  
High Strength ◽  
Content Type ◽  
Leaf Springs ◽  
Life Analysis ◽  
Fatigue Life Analysis

Purpose – The purpose of this paper is to investigate the fatigue and failure of commercial vehicle serial stress-peened leaf springs, emphasizing the technological impact of the material, the thermal treatment and the stress-peening process on the microstructure, the mechanical properties and the fatigue life. Theoretical fatigue analysis determines the influence of each individual technological parameter. Design engineers can assess the effectiveness of each manufacturing process step qualitatively and quantitatively, and derive conclusions regarding its improvement in terms of mechanical properties and fatigue life. Design/methodology/approach – Two different batches of 51CrV4 were examined to account for potential batch influences. Both specimen batches were subjected to the same heat treatment and stress-peening process. Investigations of their microstructure, hardness and residual stress state on the surface’ areas show the effect of the manufacturing process on the mechanical properties. Wöhler curves have been experimentally determined for the design of high-performance leaf springs. Theoretical fatigue analyses reveal the influence of every above mentioned technological factor on the fatigue life of the specimens. Therewith, the effectiveness and potential for further improvement of the manufacturing process steps are assessed. Findings – Microstructural analysis and hardness measurements quantify the decarburization and the degradation of the specimens’ surface properties. The stress-peening process causes significant compressive residual stresses which improve the fatigue life. On the other hand, it also leads to pronounced surface roughness, which reduces the fatigue life. The theoretical fatigue life analysis assesses the mutual effect of these two parameters. Both parameters cancel each other out in regards to the final effect on fatigue life. The sensitivity of the material and the potential for further improvement of both heat treatment and stress peening is appointed. Research limitations/implications – All quantitative values given here are strictly valid for the present leaf spring batches and should not be widely applied. The results of the present study indicate the sensitivity of high-strength spring steel used here to the various technological factors resulting from the heat treatment and the stress-peening process. In addition, it can be concluded that further research is necessary to improve the two processes (heat treatment process and the stress peening) under serial production conditions. Practical implications – The microstructure investigations in conjunction with the hardness measurements reveal the significant decrease of the mechanical properties of the highly stressed (failure-critical) tensile surface. Therewith, the potential for improvement of the heat treatment process, e.g. in more neutral and controlled atmosphere, can be derived. In addition, significant potential for improvement of the serially applied stress-peening process is revealed. Originality/value – The paper shows a systematic procedure to assess every individual manufacturing factor affecting the microstructure, the surface properties and finally, the fatigue life of leaf springs. An essential result is the quantification of the surface decarburization and its influence on the mechanical properties. The methodology proposed and applied within the theoretical fatigue life analysis to quantify the effect of technological factors on the fatigue life of leaf springs can be extended to any engineering component made of high-strength steel.

Determination of Tensile Properties of Power Plant Steels by Testing of Miniature Specimens

2013 ◽  
Author(s):  
Ivan Klevtsov ◽  
Andrei Dedov
Keyword(s):  
Mechanical Properties ◽  
Power Plant ◽  
Flat Plate ◽  
Tensile Properties ◽  
Standard Size ◽  
Term Operation ◽  
University Of Technology ◽  
Miniature Specimens

Long-term operation of the power plant components in the conditions of the creep leads to the degradation of the short-term mechanical properties of the material. Therefore, in order to predict the degree of the metal degradation and integrity of the component the determination of the mechanical properties of the actual component in service material is required. Since the standard tests requiring a significant volume of sample material cannot be applied the technique of the tensile testing of miniature flat plate specimens has been developed in Tallinn University of Technology and described in this paper. The results of the tests of miniature flat plate specimens have been compared with testing results of cylindrical specimens with standard size and at the same time the comparison has shown a good agreement of the results. The data analysis has also shown the high repeatability of the tests results of miniature specimens. Thus, the developed technique of the miniature flat plate specimens testing could be considered as accurate and reliable method and could be definitely used for evaluation of the tensile properties of the metal.

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