Abstract: Accordingly, the present invention provides a weld filler composition for joining different alloy steel pieces with substantially different chromium content, such as joining low alloy ferritic steel to high alloy ferritic steel, low alloy ferritic steel to austenitic stainless steel, or high alloy ferritic steel to austenitic stainless steel, and a method using the same. In one embodiment, the present invention provides a composition for a weld filler comprising nickel, iron, and chromium, which collectively comprise at least 50% by weight of the weld filler; niobium, carbon, manganese, molybdenum, and silicon, which collectively comprise no more than 50% by weight of the weld filler, and a niobium to carbon ratio of approximately 20 or less.

Abstract: A method for fabricating a valve includes hardened valve seats and a conventional valve stem which mates with the hardened valve seat. A valve seat support ring is attached to the body of the valve and to the hardened valve seat. HIP bonding is utilized to bond the hardened valve seat to the valve seat support ring. Conventional techniques, such as welding are used to attach the valve seat support ring to the body of the valve.