WSEAS Transactions on Applied and Theoretical Mechanics
Print ISSN: 1991-8747, E-ISSN: 2224-3429
Volume 9, 2014
Influence of Heat Input on Mechanical Properties and Microstructure of Austenitic 202 Grade Stainless Steel Weldments
Authors: ,
Abstract: Present research work investigates the effect of heat input (controlled by welding current, welding voltage and welding speed) on tensile strength, micro-hardness and microstructure of austenitic 202 grade stainless steel weldments produced by shielded metal arc welding (SMAW). The base material used in the present investigation was Cr-Mn SS and 308L SS solid electrode was used as the filler material. From the experimental results it was found that the increase in heat input affects the micro-constituents of base metal, and heat affected zone (HAZ). Tensile strength decreases with increase in heat input and from scanning electron microscopy of tensile test fractured surfaces exhibited ductile & brittle failure. From micro hardness data values it was observed that hardness of material increases with increase in heat input in weld pool and decreases in HAZ zone. Optical microscopy shows that smaller dendrite sizes and lesser inter-dendritic spacing were observed in the fusion zone at low heat input. And long dendrite sizes and large inter-dendritic spacing were observed in the fusion zone of the joint welded at high heat input. Further it was observed from the optical micrographs that the extent of grain coarsening in the HAZ increases with increase in heat input.
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Keywords: Austenitic stainless steel, Heat affected zone, Micro-hardness, Shielded metal arc welding, Ductile facture, Ultimate tensile strength
Pages: 222-228
WSEAS Transactions on Applied and Theoretical Mechanics, ISSN / E-ISSN: 1991-8747 / 2224-3429, Volume 9, 2014, Art. #20