Inconel alloy 690 is a high-chromium nickel alloy having excellent resistance to many corrosive aqueous media & high temperature atmospheres.

The superior stress cracking resistance of this alloy caused it to supersede Inconel alloy 600 in nuclear application. The tube to tubesheet (TTS) joint is one of the most critical in any heat exchanger since it acts as thinnest pressure boundary joint.

Alloy 690 has demonstrated excellent weldability for TTS joints when welded in controlled environment using consumable with restricted chemistry, however very limited information is available on TTS weld quality of alloy 690 material with various welding technique.

Present work describes alloy 690 TTS joint evaluation made with machine & manual welding process, with & without filler, and fresh & repair welding. These joints successfully cleared dye penetrant test, radiography examination and helium leak test.

This article is shared by Abhishek Dasadia, Hardik Shah and Ritesh Patel