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.