Revisiting fundamental welding concepts to improve additive manufacturing: From theory to practice

Dissimilar welding of AISI 310 austenitic stainless steel to nickel-based alloy Inconel 657

Joining of Inconel 718 and 316 Stainless Steel using electron beam melting additive manufacturing technology

Characterization of microstructures and mechanical properties of Inconel 617/310 stainless steel dissimilar welds

For joining type 316LN austenitic stainless steel to modified 9Cr–1Mo steel for power plant application, a trimetallic configuration using an insert piece (such as alloy 800) of intermediate thermal coefficient of expansion (CTE) has been sometimes suggested for bridging the wide gap in CTE between the two steels. Two joints are thus involved and this paper is concerned with the weld between 316LN and alloy 800. These welds were produced using three types of filler materials: austenitic stainless steels corresponding to 316, 16Cr–8Ni–2Mo, and the nickel-base Inconel 182 1 . The weld fusion zones and the interfaces with the base materials were characterised in detail using light and transmission electron microscopy. The 316 and Inconel 182 weld metals solidified dendritically, while the 16–8–2 (16%Cr–8%Ni–2%Mo) weld metal showed a predominantly cellular substructure. The Inconel weld metal contained a large number of inclusions when deposited from flux-coated electrodes, but was relatively inclusion-free under inert gas-shielded welding. Long-term elevated-temperature aging of the weld metals resulted in embrittling sigma phase precipitation in the austenitic stainless steel weld metals, but the nickel-base welds showed no visible precipitation, demonstrating their superior metallurgical stability for high-temperature service.

M Sireesha

Papers

A comparative evaluation of welding consumables for dissimilar welds between 316LN austenitic stainless steel and Alloy 800