Investigation on un-peened and laser shock peened dissimilar weldments of Inconel 600 and AISI 316L fabricated using activated-TIG welding technique

The joining of Inconel 600 and AISI 316L plates using compound flux of 50% SiO2 + 50% TiO2 by activated tungsten inert gas (ATIG) welding process has been addressed in this article. The various mechanical and metallurgical studies were performed on the un-peened ATIG (UP-ATIG) dissimilar weldment. The results portrayed that the tensile failure of UP-ATIG weldment had occurred at the weld zone because of the presence of coarse grains and intermetallic phases. Laser shock peening (LSP) carried out on the UP-ATIG dissimilar weldment divulged that the laser peened ATIG (LP-ATIG) weldment possesses higher tensile strength (630.33 +/- 28.02 MPa) than the UP-ATIG weldment (573.11 +/- 41.11 MPa) due to the presence of compressive residual (CR) stresses induced by LSP. The residual stress measurements revealed that the UP-ATIG weldment possesses tensile residual (TR) stresses and the LP-ATIG weldment encompasses CR stresses in the weld zone. Potentiodynamic polarization test results show that the corrosion resistance of the LP-ATIG weldment is slightly higher (I-corr = 0.19 +/- 0.02 mA/cm(2)) than the UP-ATIG weldment (I-corr = 0.21 +/- 0.05 mA/cm(2)).