Type 316L(N) stainless steel is one of the major structural materials for the sodium cooled fast breeder reactor (FBR) at Kalpakkam. Spin arc welding also known as rotating arc welding is a variant of gas metal arc welding process.

In this process, the arc is rotating during deposition of filler material. This process has simple edge preparation with high productivity hence this can be used to join plates of higher thickness. In the present work, 316LN plates of 12 mm thick were used in the preparation of weldments in 1G position.

The parameters were optimized to obtain weldments that are visually acceptable as well as X-ray radiographic qualified weldments. Feritscope measurement shows that the weld has delta ferrite content in the range of 4.5 FN - 5 FN. The tensile properties are: UTS: 595 MPa; YS: 380 MPa. The weld has higher strength than other zones of weldment as indicated by Vickers microhardness survey.

By varying the arc rotation, it is possible to obtain the higher productivity in plates of equivalent thickness. The distortion of weldments after the welding was found to be minimum due to narrow groove as well as square edge preparation.

The average impact energy of the welds found to be 160 Joules at room temperature. Further studies show that this process offers the scope to improve the productivity of 20 mm thick plates.

This article is shared by B. Arivazhagan, V. Lakshmanan and P. Sathiya.