Effect of welding processes and conditions on the microstructure, mechanical properties and corrosion resistance of duplex stainless steel weldments—A review

At present aluminium-magnesium alloys are widely used in various engineering applications due to its light weight and superior properties. Joining is considered as one of the most complex phenomenon in various precision industries like aerospace, railway, automotive and marine structures because inflexible tolerances are required during different product assembly. The friction stir welding (FSW) of aluminium-magnesium of various grade has incited substantial scientific and industrial importance since it has a potency to transform the product with a good quality joint. The fabrication of such alloys is a challenging task through conventional fusion welding due to its various metallurgical concerns. Therefore, the present work is intended to summarize the recent progress in FSW of aluminium-magnesium alloys. Particular attention has been paid to microstructural evolution, phase transformation, recrystallization mechanism, material flow behaviour and how the process parameters influence the various mechanical properties and associated defects during FSW. Various experimental and numerical simulation results have been mentioned for weld property comparison. Finally, this work not only points out the prominent conclusions of the preceding research but also recommends the upcoming guidance concerning to fabrication of aluminium-magnesium alloys through FSW.

Recent research progress in solid state friction-stir welding of aluminium–magnesium alloys: a critical review

The paper critically assesses the research progress towards aluminium–magnesium dissimilar friction stir welding (FSW). First, the theoretical requirements are explored through the understanding of joining mechanism and heat generation in aluminium–magnesium FSW. Next, the observed trends in microstructural characterisation and mechanical properties are analysed. Finally, the effects of welding parameters and how it influences process variables and materials responses are discussed in detail, and several suggestions are made based on these discussions.

Review of research progress on aluminium–magnesium dissimilar friction stir welding

In this work, a functionally graded material (FGM) part was fabricated by depositing a Cu-based alloy on top of a high strength low alloy (HSLA) steel by twin-wire and arc additive manufacturing (T-WAAM). Copper and steel parts are of interest in many industries since they can combine high thermal/electrical conductivity, wear resistance with excellent mechanical properties. However, mixing copper with steel is difficult due to mismatches in the coefficient of thermal expansion, in the melting temperature, and crystal structure. Moreover, the existence of a miscibility gap during solidification, when the melt is undercooled, causes serious phase separation and segregation during solidification which greatly affects the mechanical properties. Copper and steel control samples and the functionally graded material specimen were fabricated and investigated using optical microscopy, scanning electron microscopy, and high energy synchrotron X-ray diffraction. Retained δ-ferrite was found in a Cu matrix at the interface region due to regions with mixed composition. A smooth gradient of hardness and electric conductivity along the FGM sample height was obtained. An ultimate tensile strength of 690 MPa and an elongation at fracture of 16.6% were measured in the FGM part. 

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Steel-copper functionally graded material produced by twin-wire and arc additive manufacturing (T-WAAM)

Steel-copper functionally graded material produced by twin-wire and arc additive manufacturing

In the present study, dissimilar alloys such as Mg-AZ31B and Al-AA6061 were joined by friction stir welding using different rotational (560, 710, 860 and 1010 rpm) and transverse speeds (16 and 25 ...

Effect of friction stir welding process parameters on Mg-AZ31B/Al-AA6061 joints

Dissimilar welding behavior of 22% Cr series stainless steel with 316L and its corrosion resistance in modified aggressive environment

There are many industrial situations particularly in petro-chemical, marine, power plant and other such industries where the use of dissimilar metal weldments is necessary, mainly due to economic benefits and also sometimes to improve the performance of the component. Both austenitic stainless steels and duplex stainless steels have received much attention in recent days due to their superior anti-corrosive and mechanical properties. Further, the use of shielded metal arc welding (SMAW) process is inevitable in engineering industries. In the present work, microstructure, mechanical and intergranular corrosion behavior of dissimilar 2205 duplex stainless steel and 316L austenitic stainless steel fabricated by SMAW process using E2209 electrode by taking two different heat input (0.45–0.60 kJ/mm) was investigated. The microstructures were characterized by using optical microscopy and scanning electron microscopy (SEM), while the localized chemical information was obtained by an energy dispersive spectrometer attached to the SEM. Double loop electrochemical potentiokinetic reactivation test was performed to quantitatively assessing the intergranular corrosion based on degree of sensitization. The effect of weld dilution on mechanical properties (i.e. tensile/hardness properties) was also studied. The ferrite content was experimentally measured by using ferritoscope and it was observed that the weld joint achieved the required ferrite content for both the heat inputs. Higher ferrite content (results of faster cooling rate) increased the hardness and tensile strength of low heat input as compared to high heat input. While, high heat input improved the corrosion resistance due to formation of higher austenitic phases. Higher impact energy was observed in E2209 weld metal than that of the base metals. No welding defects were observed and recommended for industrial use.

Microstructure, Mechanical and Intergranular Corrosion Behavior of Dissimilar DSS 2205 and ASS 316L Shielded Metal Arc Welds

In recent years, the development and use of composite materials are gaining importance in the field of aerospace, automobile, marine and other industrial applications because of their potential properties such as higher specific strength and better corrosion and fatigue properties than most metals. The ever-increasing temperatures on earth surface and the use of non-biodegradable materials for industrial applications lead to increase in global warming which forced the researchers to work on green composites that suite the properties and reliability of the metals, alloys, composites. The increase in use of polymers which are not biodegradable increases air and water pollution. Development of green composites helps to maintain ecological balance. The review of this article focuses on discussing the green matrix material and modifications needed for fibers to improve the properties of green composites.

Jagesvar Verma

Papers

Effect of welding processes and conditions on the microstructure, mechanical properties and corrosion resistance of duplex stainless steel weldments—A review

Effect of friction stir welding process parameters on Mg-AZ31B/Al-AA6061 joints

Dissimilar welding behavior of 22% Cr series stainless steel with 316L and its corrosion resistance in modified aggressive environment

Microstructure, Mechanical and Intergranular Corrosion Behavior of Dissimilar DSS 2205 and ASS 316L Shielded Metal Arc Welds

Potential biodegradable matrices and fiber treatment for green composites: A review