High Nickel Alloys
Home / HIGH NICKEL ALLOYS
Home / HIGH NICKEL ALLOYS
Nickel 200 Alloy is a commercially pure nickel (99.6%) that exhibits good corrosion resistance and has rather low electrical resistivity. It’s used in caustic solutions, food handling equipment, and general corrosion-resistant parts and structures. Because it contains magnetic and mechanical properties, it can be used in devices that require magnetic actuated parts.
Nickel 201 Alloy is similar to Nickel 200 Alloy and is a low carbon modification of the 200 Alloy. It has a low annealed hardness and very low work-hardening rate. Those who use Nickel 201 Alloy find it desirable in deep drawing, spinning, and coining. It addition, it can be applied to corrosion-resistant equipment including but not limited to: caustic evaporators, spun anodes, and laboratory crucibles.
Monel 400 is a nickel-copper alloy that is resistant to sea water and steam at high temperatures as well as to salt and caustic solutions. It is a solid solution alloy that can only be hardened by cold working. This nickel alloy exhibits characteristics like good corrosion resistance, good weldability and high strength. A low corrosion rate in rapidly flowing brackish or seawater combined with excellent resistance to stress-corrosion cracking in most freshwaters, and its resistance to a variety of corrosive conditions led to its wide use in marine applications and other non-oxidizing chloride solutions. This nickel alloy is particularly resistant to hydrochloric and hydrofluoric acids when they are de-aerated. As would be expected from its high copper content, alloy 400 is rapidly attacked by nitric acid and ammonia systems.
Monel 400 has great mechanical properties at subzero temperatures, can be used in temperatures up to 1000° F, and its melting point is 2370-2460° F.
Monel K500 is a precipitation-hardenable nickel-copper alloy that combines the excellent corrosion resistance characteristic of Monel 400 with the added advantage of greater strength and hardness. These amplified properties, strength and hardness, are obtained by adding aluminum and titanium to the nickel-copper base and by a thermal processing used to effect precipitation, typically called age hardening or aging. Monel K-500 has a greater tendency toward stress-corrosion cracking in some environments than Monel 400. Alloy K-500 has approximately three times the yield strength and double the tensile strength when compared with alloy 400. It can be further strengthened by cold working prior to precipitation hardening.
The strength of this nickel steel alloy is maintained to 1200° F but stays ductile and tough down to temperatures of 400° F. Its melting range is 2400-2460° F.
Hastelloy C276 is a nickel-molybdenum-chromium superalloy with an addition of tungsten designed to have excellent corrosion resistance in a wide range of severe environments. The high nickel and molybdenum contents make the nickel steel alloy especially resistant to pitting and crevice corrosion in reducing environments while chromium conveys resistance to oxidizing media. The low carbon content minimizes carbide precipitation during welding to maintain corrosion resistance in as-welded structures. This nickel alloy is resistant to the formation of grain boundary precipitates in the weld heat-affected zone, thus making it suitable for most chemical process application in an as welded condition.
Hastelloy C22 is a versatile austenitic nickel-chromium-molybdenum-tungsten alloy with enhanced resistance to pitting, crevice corrosion and stress corrosion cracking. The high chromium content provides good resistance to oxidizing media while the molybdenum and tungsten content give good resistance to reducing media. This nickel steel alloy also has excellent resistance to oxidizing aqueous media including wet chlorine and mixtures containing nitric acid or oxidizing acids with chlorine ions. Other corrosives Hastelloy C-22 has resistance to are oxidizing acid chlorides, wet chlorine, formic and acetic acids, ferric and cupric chlorides, sea water, brine and many mixed or contaminated chemical solutions, both organic and inorganic. This nickel alloy also offers optimum resistance to environments where reducing and oxidizing conditions are encountered in process streams. This is beneficial in multi- purpose plants where such “upset” conditions occur frequently.
This nickel alloy resists the formation of grain-boundary precipitates in the weld heat-affected zone, thus making it suitable for most chemical process applications in the as-welded condition.
Inconel 600 is a nickel-chromium alloy used for applications that require corrosion and high temperature resistance. This nickel alloy was designed for service temperatures from cryogenic to elevated temperatures in the range of 2000° F. It is non-magnetic, has excellent mechanical properties, and presents the desirable combination of high strength and good weldability under a wide range of temperatures. The high nickel content in Inconel 600 enables it to retain considerable resistance under reducing conditions, makes it resistant to corrosion by a number of organic and inorganic compounds, gives it excellent resistance to chloride-ion stress-corrosion cracking and also provides excellent resistance to alkaline solutions. Typical applications of this nickel alloy include the chemical, pulp and paper, aerospace, nuclear engineering and heat treating industries.
Inconel 601 is a nickel-chromium alloy used for applications that require resistance to corrosion and heat. This nickel alloy stands out due to its resistance to high temperature oxidation, remaining highly resistant to oxidation through 2200° F. Alloy 601 develops a tightly adherent oxide scale which resists spalling even under conditions of severe thermal cycling. This nickel alloy has good high temperature strength, and retains its ductility after long service exposure. It has good resistance to aqueous corrosion, high mechanical strength, and is readily formed, machined and welded.
Inconel 625 is a corrosion and oxidation resistant nickel alloy that is used both for its high strength and outstanding aqueous corrosion resistance. Its outstanding strength and toughness is due to the addition of niobium which acts with the molybdenum to stiffen the alloy’s matrix. Alloy 625 has excellent fatigue strength and stress-corrosion cracking resistance to chloride ions. This nickel alloy has excellent weldability. This alloy resists a wide range of severely corrosive environments and is especially resistant to pitting and crevice corrosion.
Incoloy 825 is a nickel-iron-chromium alloy with additions of molybdenum, copper and titanium. This nickel steel alloy’s chemical composition is designed to provide exceptional resistance to many corrosive environments. It is similar to alloy 800 but has improved resistance to aqueous corrosion. It has excellent resistance to both reducing and oxidizing acids, to stress-corrosion cracking, and to localized attack such as pitting and crevice corrosion. Alloy 825 is especially resistant to sulfuric and phosphoric acids. This nickel steel alloy is used for chemical processing, pollution-control equipment, oil and gas well piping, nuclear fuel reprocessing, acid production, and pickling equipment.
Alloy 904L is a super austenitic stainless steel that is designed for moderate to high corrosion resistance in a wide range of process environments. The combination of high chromium and nickel content, coupled with additions of molybdenum and copper, assure good to excellent corrosion resistance. With its highly alloyed chemistry—25% nickel and 4.5% molybdenum, 904L provides good chloride stress corrosion cracking resistance, pitting and general corrosion resistance superior to 316L and 317L molybdenum enhanced stainless steels. Alloy 904L was originally developed to withstand environments containing dilute sulfuric acid. It also offers good resistance to other inorganic acids such as hot phosphoric acid as well as most organic acids. Alloy 904L is easily welded and processed by standard shop fabrication practices.
Alloy 20, is a nickel-iron-chromium austenitic alloy that was developed for maximum resistance to acid attack, specifically sulfuric acid. This superalloy has excellent resistance to general corrosion, pitting, and crevice corrosion in chemicals containing chlorides and sulfuric, phosphoric, and nitric acids. It also contains niobium for stabilization against sensitization and resultant intergranular corrosion. Carpenter 20 combines excellent corrosion resistance with elevated mechanical properties and relatively easy fabrication.
Grade 1 has very good weld ability. Being substantially single-phase material, the micro structure of the alpha phase is not affected greatly by thermal treatments or welding temperatures. Therefore, themechanical properties of a correctly welded joint are equal to, or exceed those of the parent metal and show good ductility.
Grade 2 has very good weld ability. Being substantially single phase material, the micro structure of the alpha phase is not affected greatly by thermal treatments or welding temperatures. Therefore, the mechanical properties of a correctly welded joint are equal to, or exceed those of the parent metal and show good ductility. Compressor blades, discs and rings for jet engines, aircraft components, pressure vessels, rocket engine cases, offshore pressure vessels.
Since the two-phase micro ctructure of alpha-beta titanium alloys responds to thermal treatment, the temperatures encountered during the welding cycle can affect the material being welded.