Abstract
The study has compared the effect of gas metal arc welding techniques on some mechanical properties of duplex stainless steel. The samples after welded were given post weld heat treatment (quenching in engine and neem oil). After the analyses, it was established that duplex stainless steel can be weld successfully using gas metal arc welding process (GMAW). Both Lubricating oil and neem oil can serve as quenching medium for post welding heat treatment of duplex stainless steel. The results of the studies also show that welding and heat treatment really affect the mechanical properties of the alloy; the control strength was 811.47 MN/m2 while that of the welded samples ranged from 177.07 to 257.32 MN/m2. The control impact energy was 162.70 J, while that of the welded samples ranged from 38.64 J to 56.20 J. The research also shows that the stress relief heat treatment gives better strength (A3 = 331 MN/m2) compared to those that were quenched in lubricating oil (A2 = 329 MN/m2) and neem oil (A1 = 222 MN/m2), but the reverse is the case in terms of toughness.
Highlights
A large number of failures in industries are either directly or indirectly attributed to welds because of the inhomogeneity within the weldment, stress concentration, residual stress, inclusion of impurities etc. which invariably make it the weakest region [1]
Duplex stainless steel was the main material used for this research work which was sourced locally at Jos building materials market in Nigeria, while its chemical composition was determined at National Metallurgical Center Jos using the XFR test
The results shows that samples that underwent stress relief treatment after welding has higher tensile strength, next to those treated in lubricating oil, while those treated in neem oil has the lowest in their group
Summary
A large number of failures in industries are either directly or indirectly attributed to welds because of the inhomogeneity within the weldment, stress concentration, residual stress, inclusion of impurities etc. which invariably make it the weakest region [1]. Duplex stainless steels are mostly selected because of their combination of high strength and corrosion resistance Their full potential is used in locations where the material comes into contact with salt water or where high concentrations of chlorides are present in the ambient air or where de-icing salts are of a concern. With all their afore-mentioned favorable properties, the duplex stainless steels still fail mostly at the weld points which can be as a result of the welding process, process variables used and the welding environmental contamination. This work will look at the effect of stress relief, full annealing, normalizing, and hardening heat treatment methods on the mechanical properties of duplex stainless steel
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
