The Effects of TIG Welding Rod Compositions on Phase Distributions and Corrosion Properties of Dissimilar 304L and 420 Stainless Steel Welds

Authors : Mustafa Gökhan Murat, Aziz Barış Başyiğit

Pages : 134-147

Doi:10.29137/umagd.616829

View : 30 | Download : 7

Publication Date : 2020-01-31

Article Type : Research

Abstract :304L austenitic and 420 martensitic stainless steels are demanded in wide range of industries. 304L alloy exhibits good resistance to oxidizing medias up to 760°C and they also maintain superior impact properties at cryogenic temperatures while 420 alloy provides the strength values close to tool steels in with satisfactory corrosion properties in ambient atmospheres.   In this work; 420 plate is TIG (Tungsten Inert Gas) welded with 304L plate with both thicknesses of 3 mm. Welding operation is applied by two passes under pure argon gas also with shielding the weld root. 3 types of TIG welding rods; ER312, ER316L and ER2209 are used in TIG welding for ensuring 3 different weld metal compositions. The effects of TIG welding rod type on weld metal phase ratios with microstructural and corrosion properties are investigated. Microstructural inspections and corrosion (weight loss) tests are applied to all joints after welding operations.   The sample joined by ER312 TIG rod transformed the weld metal into dendritic microstructure and the sample joined by ER2209 TIG rod resulted in globular type of weld metal microstructure. The specimen that welded by ER316L type TIG welding rod resulted in the best corrosion test values among all welded samples.
Keywords : 420 and 304L stainless steels, TIG welding, phase analysis, corrosion of stainless steels