The possible solidification modes of austenitic stainless steels joints according to different chemical compositions and cooling rates

Abstract

The microstructures of four welded joints of austenitic stainless steel were studied to better understand the effect of different cooling rates on the volume fraction of δ-ferrite phase, in overlay deposits obtained by SMAW process. The weld pads were carried out using E316L and E347 electrodes and adjusting welding parameters to provide high and low heat. The weld pads produced were submitted to different cooling rates, being one produced by applying higher heat input and cooling in air, and another by applying lower heat input and cooling in water. Complementary techniques of microstructural analysis were applied, such as optical emission spectrometry, optical microscopy, and quantitative image analysis. There was an increase in the volume fraction of δ-ferrite in the weld pads, executed using the welding electrode E347, as the cooling rate increased. On the other hand, it was observed the opposite effect in the weld pads manufactured with the E316L welding electrode. The results suggest that the solidification mode of E347 is ferritic-austenitic and it is austenitic-ferritic in the case of E316L.

Keywords:

• Solidification mode
• ferrite number
• chemical composition

SUBJECT CLASSIFICATION CODES:

• include these here if the journal requires them

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico [304741/2020-5 and 307044/2023-8]; Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco [APQ-0964-3.03/21].