Weld Mold 4625 description: Weld Mold 4625 is used for overlaying steel, welding various nickel base alloys, and dissimilar joints involving various nickel base alloys, carbon steels, low alloy steels, and stainless steels. 4625 is used for the welding of Inconel alloy 601, 625 and 690, and Incoloy 800 HT. It is also used for welding of corrosion resistant steels. Nickel steels can also be welded and as overlayment on various steels. 4625 has high strength over various temperature ranges and excellent corrosion resistance such as pitting and crevice corrosion.