Materials Engineers Group Ltd.

Tyrawa Wołoska, Poland

Materials Engineers Group Ltd.

Tyrawa Wołoska, Poland
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Jurcius A.,Vilnius Gediminas Technical University | Valiulis A.V.,Vilnius Gediminas Technical University | Cernasejus O.,Vilnius Gediminas Technical University | Kurzydlowski K.J.,Warsaw University of Technology | And 2 more authors.
Journal of Vibroengineering | Year: 2010

The welding process can join two similar materials with a bond that has mechanical properties comparable to the original material. Unfortunately, this process induces residual stresses in the weldment, which, if left untreated, can cause distortion of the part, premature fatigue failure or cracking along the weld. A post-weld heat treatment is the traditional method of relieving these stresses, but is costly and a time consuming process. Heat treatment is required for weldments, which have heavy fatigue loading since the post-weld heat treatment reduces the residual stresses in the weldment and generates more uniform mechanical properties. Vibratory stress relief (VSR) techniques could be used to substitute the heat treatment for these types of weldments and save time and money. The purpose of this paper is to provide a brief overview of the generation, measurement, and reduction of residual stresses. Residual stresses in the weld bead were measured by means of X-ray diffraction, ultrasonic technique and hole drilling methods. In addition, welded specimens were subjected to mechanical testing with purpose of determination of VSR effect on weld and heat-affected zone metal. © Vibromechanika. Journal of Vibroengineering.


Skindaras R.,AB ORLEN Lietuva | Valiulis A.V.,VGTU | Spychalski W.L.,Materials Engineers Group Ltd
Mechanika | Year: 2013

In the petrochemical industries cast steel tube coil sheets with high chromium and nickel content are used. The operation range of these alloys are 533 to 1150°C. A paramount for these alloys are: - corrosion and scaling resistance at high temperatures; - dimensional stability, i.e. resistance to warping, cracking and thermal fatigue; - resistance to plastic flow, i.e. creep strength. Tube coil sheet of furnace resulting in aggregate failures have been considered. Life span of the studied specimens obtained from tube coil sheet was 3 years. After a few years of exploitation several hollow cracks on the heater tubesheet were identified. Preoxidation of the tubes surface are possible and it has not only favourable effects: during cooling cracks may form in the oxide layer. The aim of the performed research was to characterize the microstructure and mechanical properties of the investigated alloy after ageing at the temperature of 900°C. The high temperature determine elements diffusion in the structure, emergence of chromium and niobium carbides and other precipitates and cause the changes in the mechanical properties.


Malesa M.,Warsaw University of Technology | Malowany K.,Warsaw University of Technology | Pawlicki J.,Warsaw University of Technology | Kujawinska M.,Warsaw University of Technology | And 4 more authors.
Engineering Failure Analysis | Year: 2016

Although Digital Image Correlation (DIC) provides capabilities of scaling a field-of-view (FOV), dimensions of some industrial installations in many cases are too big to be measured with DIC based on a single camera pair. In this paper we present two strategies of spatial stitching of data obtained with multi-camera DIC systems that can be used for engineering failure analysis, namely strategy for the case when there are overlapping FOVs of 3D DIC setups and strategy for the case when 3D DIC setups are distributed and not necessarily have overlapping FOVs. Data obtained with the presented methodologies can be used to verify or update FEM models of the investigated objects. Two practical applications of the multi-camera DIC system are described in order to show its feasibility in engineering failure analysis. © 2016.


Malesa M.,Warsaw University of Technology | Kujawinska M.,Warsaw University of Technology | Malowany K.,Warsaw University of Technology | Lusa T.,Materials Engineers Group Ltd.
Procedia Engineering | Year: 2015

A multi-camera Digital Image Correlation (DIC) systems have been developed to match the specific requirements for measurements posed by building and petrochemical industries. The two most important issues are connected with considerable dimensions of objects and a time line of the measurements. Although DIC provides capabilities of scaling a field-of-view (FOV), dimensions of industrial installations in many cases are too big to be measured with DIC based on a single camera pair. In this paper we present two strategies that can be used for spatial stitching of the data obtained with multi-camera DIC systems, namely a strategy for the case when there are overlapping FOVs of 3D DIC setups and a strategy for the case when 3D DIC setups are distributed and not necessarily have overlapping FOVs. Two practical applications of the multi-camera DIC system are described in order to show its feasibility in industry. © 2015 Published by Elsevier Ltd.

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