Prevent Cracking in Deposition of Carbon Steel on Inconel 625

Abstract

Welding procedure of clad steel including deposition of carbon steel on nickel base alloy usually gives unaccepted mechanical properties. Cracks were formed along type II boundary in nickel base alloy pass and a martensitic layer was formed in carbon steel pass. In this paper, cracks along type II boundary were prevented by lowering the martensitic start temperature (TMs) of the martensitic layer. Decreasing of TMs was obtained by two methods: Dilution method and Grain refining method. Three levels of TMs (approximately 350, 200, and 50⁰C) are obtained. The results showed that: cracks along type II boundary were prevented at TMs lower than 200⁰C; however type II boundary itself was prevented at TMs lower than 50𠜌. Also post weld heat treatment was necessary to achieve accepted impact properties.