Stainless steel is a widely used material in various industries such as aerospace, chemical processing and transportation. Tungsten Inert Gas (TIG) or Gas Tungsten Arc Welding (GTAW) process is ext...

A novel perception toward welding of stainless steel by activated TIG welding: a review

Special attention is required when joining two materials with distinct chemical, physical and thermal properties in order to make the joint bond robust and rigid. The goal of this study was to see how significantly different tungsten inert gas (TIG) welding process parameters (welding current, gas flow rate, root gap, and filler materials) affect mechanical properties (tensile, hardness, and flexural strength), as well as the bead width and microstructural properties, of dissimilar welds In comparison to SS 316 and AISI 1020 low-carbon steel. TIG welding parameters were optimized in this study using a Taguchi-based desirability function analysis (DFA). From the experimental results, it was observed that welded samples employing ER-309L filler wires had a microstructure consisting of a delta ferrite network in an austenite matrix. The tensile strength experimental results revealed that welding current, followed by GFR, was a highly influential parameter on tensile strength. Weld metals had higher hardness and flexural strength than stainless steel and carbon steel base metals. This was supported by the fact that the results of our tests had hardness ratings greater than a base for the FZ and HAZ, and that no crack was observed in the weld metal following U-shape flexural bending. Welding current has a significant impact on the bead width of welded specimens, followed by root gap. Furthermore, the dissimilar welded sample responses were optimized with a composite desirability percentage improvement of 22.90% by using a parametric setting of (A2B4C4D2). Finally, the validation of the experiment was validated by our confirmation test results, which agreed with the predictive optimum parameter settings.

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Experimental Investigation and Parametric Optimization of the Tungsten Inert Gas Welding Process Parameters of Dissimilar Metals

Effect of weld defects on the mechanical properties of stainless-steel weldments on large cruise ship

This paper made efforts on investigating low-temperature mechanical properties of new constructional stainless steel (SS) QN1906Mo. Forty-two tensile coupons were firstly tensioned at four low temperatures of 30, -30, -60, and -80 °C. Environment for testing low temperatures was realized through an insulation chamber with injecting LNG. The test results reported low-temperature mechanical properties of SS QN1906Mo materials and welds. Test results showed that decreasing the temperature from 30 to -80 °C did not affect the ductility and elastic Young’s modulus of SS QN1906Mo material, but significantly increased yield and ultimate strengths of SS QN1906Mo material by 37% and 35%. Decreasing the temperature from 30 to -80 °C also exhibited equivalent increments in yield or ultimate for weld coupons to those material coupons but with much larger scatters due to the air voids in the weld coupons. Finally, this paper developed constitutive models to describe stress–strain laws of SS QN1906Mo at varying T range of -80 ∼ 30 °C, which were proved their capabilities. • Stainless steel (SS) QN1906Mo exhibited ductile failure mode at low temperatures ( T ). • Decreasing T from 30 to -80 ℃ did not affect elastic modulus of SS QN1906Mo. • Low temperatures significantly increase yield/ultimate strengths of SS QN1906Mo. • SS QN1906Mo provides larger yield and ultimate strength than SS 316L. • Developed constitutive models described well stress–strain behaviours of SS QN1906Mo at low temperatures. 

P. Anbarasu

Papers

Investigation of filler material influence on hardness of TIG welded joints