Microstructure variation effects influence on characteristics and mechanical properties of Monel 400 and low alloy steel (ASTM 387-Gr.11) GTAW dissimilar joint

Abstract

Monel 400 with low alloy steel dissimilar joints are widely used in oil industry, petrochemical and nuclear engineering, this kind of applications needs welding joints with good mechanical properties, stable magnetic permeability and good weldability. Difference in mechanical, chemical and physical properties between these unique alloys makes such joint difficult and joints mechanical properties and microstructure will be different from parent metals. In this study, GTAW process has been employed with ERNiCrFe-3 electrode to produce dissimilar welding joints with specifies welding procedure parameters, SEM/EDS microstructure analysis, microstructure optical test, Vickers microhardness and tensile test used to study microstructure details and its impacts on welding joint mechanical properties. Research results according to welding zone microstructure analyses shown formation of Widmanstatten ferrite structures and second phase particles with fine graine structure in low alloy steel side the formation of transion zone (TZ). Moreover, clearly fusion line (FL) clearly marked in Monel 400 side while weld metal solidification microstructure with (MGBs) and (SGBs) respectively and interdendritic microstructure observed in weld zone center. Weldment mechanical and microstructure examination indicated the ability to produce like this dissimilar joint with requirement of design criteria and indicated that the failure in like this joint excepted to be in low alloy steel side. The result and microstructure analyses of this research is very important to understanding the variation in welding zone and HAZ microstructure and its impact in weldment mechanical properties and establish the base to produced best welding procedure according to welding zone microstructure properties.

Microstructure, Mechanical Properties, and Heat Distribution ANSYS model of CP Copper and 316 Stainless Steel Torch Brazing

“…Low-silver-content flux-coated torch brazing filler wire was used with 20% silver brazing filler. Base metal tubes and flux-coated low silver brazing commercial filler chemical compositions with filler melting temperatures are listed in Tables (1)(2)(3). A mixture of propane and oxygen was used as brazing fuel to generate the required brazing temperatures between 780 °C and 810 °C to melt the low silver contain filler.…”

“…The copper penetrating phenomenon has essential acts in austenitic stainless-steel embrittlement. This crack type can be found in grain boundaries between the stainless-steel interface and the joining fusion zone (FZ) [2,3]. According to earlier research, molten liquid copper diminished stainless-steel strength by up to 35% and decreased elongation by up to 73% [4].…”

Comparison of the accuracy of OES and EDX tests on nickel dissolving in brass casting

“…The yield strength of the alloy gives an increase of up to 51 % and hardness of up to 30 % [13]. Nickelbased materials have superior mechanical properties while adding other elements [14]. Nickel element is a good material for improving mechanical properties, especially strength in brass alloys.…”

Microstructure and Mechanical Properties Assessments of 304 Austenitic Stainless Steel and Monel 400 Dissimilar GTAW Weldment

“…Monel 400 and AISI 304 dissimilar weldments highly required in applications must accommodate for corrosive environment with moderate strength demanded at high temperatures. These dissimilar weldments extensively used with food industry equipment, oil gasification equipment, feed water plants in boilers and petrochemical facilities [3][4][5].…”