The effects of corrosion behavior of duplex stainless steel weld metals with nitrogen additions were discussed. The addition of nitrogen to the weld metal was achieved through shelding gas and the resultant weld metals were assessed for their microstructural features and corrosion behavior. Metal/film interface was detected using Auger electron and X-ray photoelectron analysis. The results show that shielding gas mixture can help in obtaining quality welds with desired phase balance and corrosion resistance.

Suresh Krishnamoorthy Seshadri

Electrolytes

Fabrication

Grain boundaries

Metallography

microstructure

nitrogen

pH effects

Pitting

Stainless steel

Welding

X ray photoelectron spectroscopy

AUTOGENOUS WELDING

SHIELDING GAS MIXTURE

Corrosion resistance

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Corrosion behaviour of duplex stainless steel weld metals with nitrogen additions

Corrosion Engineering Science and Technology

The gas tungsten arc (GTA) welding process is widely employed for fabricating duplex stainless steel (DSS) components. The microstructural phase balance is disturbed in DSS welds owing to the thermal cycles associated with welding and the desired phase balance is generally achieved either through control of heal input or by altering the composition. In GTA welding, the phase balance is obtained either via the use of nickel fortified fillers or by introduction of nitrogen. Control of ferrite in the welds is essential, since metastable ferrite may transform to secondary austenite during multiple pass welding. The present work describes the influence of nitrogen on the phase balance of DSS welds and also its controlling effect on the secondary austenite formation in multiple pass welds. It was observed that neither the nitrogen addition nor the secondary austenite formation influenced the hardness of the welds, but formation of secondary austenite led to a deterioration in corrosion resistance. The corrosion resistance of welds containing secondary austenite (SA) was observed to be inferior to that of SA free weld metals. © 2004 IoM Communications Ltd.

Science and Technology of Welding and Joining

Effect of nitrogen addition on formation of secondary austenite in duplex stainless steel weld metals and resultant properties

Duplex Stainless Steels

Applications

Corrosion Resistance Properties

Corrosion Engineering, Science and Technology

Corrosion news and views

Journal of Materials Engineering and Performance

Influence of nitrogen in the shielding gas on corrosion resistance of duplex stainless steel welds

Materials Science Forum

Low Cycle Fatigue of High Nitrogen Duplex Stainless Steels

Journal	Corrosion Engineering Science and Technology
ISSN	1478422X
Open Access	No