Cast iron high-nickel

The ecological and economic consequences of recovering 4500 lbs. per month of a 32% ferro-nickel alloy are impressive. This material can be saleable feedstock to industries producing wrought stainless steel, stainless steel castings, and high-nickel cast irons. Instead of a cost and liability, we now have a profit center. 

HIgh-nIckel austenitic oast Irons. High-nickel austenitic cast irons contain large percentages of nickel and copper and are fairly resistant to acids. When nickel levels exceed 18%, austenitic cast irons are nearly immune to alkalies or caustics, although SCC can occur. High-nickel cast irons can be nodularized to yield ductile irons. 

The greatest use of cubic boron nitride is as an abrasive under the name Bora2on, in the form of small crystals, 1—500 p.m in si2e. Usually these crystals are incorporated in abrasive wheels and used to grind hard ferrous and nickel-based alloys, ranging from high speed steel tools and chilled cast-iron to gas turbine parts. The extreme hardness of the crystals and their resistance to attack by air and hot metal make the wheels very durable, and close tolerances can be maintained on the workpieces. 

Another group of cast-iron alloys are called Ni-Resist, These materials are related to gray cast iron in that they have high carbon contents (3 percent), with fine graphite flakes distributed throughout the structure. Nickel contents range from 13.5 to 36 percent, and some have 6.5 percent Cu. 

Corrosion resistance of nickel allovs is superior to that of cast irons but less than that of pure nickel. There is uttle attack from neutral or alkaline solutions. Oxidizing acids such as nitric are highly detrimental. Cold, concentrated sulfuric acid can be handled. 

Cast irons are iron with high levels of carbon. Heat treatments and alloying element additions produce gray cast iron, malleable iron, ductile iron, spheroidal cast iron and other grades. The mechanical properties vary significantly. Nickel-containing cast irons have improved hardness and corrosion resistance. Copper or molybdenum additions improve strength. 

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