Abstract: This invention related to a high carbon and high molybdenum/tungsten martenisitic type iron base alloy with excellent hot hardness and wear resistance for making valve seat insert. The alloy comprises of 2.05-3.60 wt % carbon, 0.1-3.0 wt % silicon, 0-2.0 wt % manganese, 3.0-10.0 wt % chromium, 11.0-25.0 wt % molybdenum and tungsten, 0.1-6.5 wt % nickel, 0-8.0 wt % vanadium, 0-6.0 wt % niobium, 0-8.0 wt % cobalt, and the balance being iron with impurities.

Abstract: This invention related to a novel iron base alloy using residual austenite to improve wear resistance for valve seat insert material for internal combustion engines. The residual austenite is stable even after heat treatment and liquid nitrogen chilling. The alloy comprises of 2.0-4.0 wt % carbon, 1.0-3.0 wt % silicon, 0-4.0 wt % manganese, 3.0-9.0 wt % chromium, 5.0-15.0 wt % molybdenum, 3.0-15.0 wt % nickel, 0-6.0 wt % vanadium, 0-4.0 wt % niobium, 0-6.0 wt % cobalt, and the balance being iron with impurities.

Abstract: A unique austenitic iron base alloy for wear and corrosion resistant applications, characterized by its excellent sulfuric acid corrosion resistance and good sliding wear resistance, is useful for valve seat insert applications when corrosion resistance is required. The alloy comprises 0.7-2.4 wt % carbon, 1.5-4 wt % silicon, 3-9 wt % chromium, less than 6 wt % manganese, 5-20 wt % molybdenum and tungsten combined, with the tungsten comprising not more than ? of the total, 0-4 wt % niobium and vanadium combined, 0-1.5 wt % titanium, 0.01-0.5 wt % aluminum, 12-25 wt % nickel, 0-3 wt % copper, and at least 45 wt % iron.