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Stellite is a type of cemented carbide that can resist various forms of wear and corrosion, as well as high-temperature oxidation. These are what are commonly referred to as cobalt-chromium-tungsten (molybdenum) alloys or cobalt-based alloys; Stellite alloys were invented by the American Elwood Hayness in 1907. Tai Li alloy is a type of alloy whose main component is cobalt, and it contains a considerable amount of nickel, chromium, and tungsten, as well as small amounts of molybdenum, niobium, tantalum, titanium, lanthanum, and other alloying elements; occasionally, iron is also present in such alloys. Depending on their composition, they can be made into welding wires; the powder can be used for hardfacing, thermal spraying, spray welding, and other processes, and they can also be used to produce cast and forged parts as well as powder metallurgy components. Classified by their application areas, Stellite alloys can be divided into Stellite wear-resistant alloys, Stellite high-temperature resistant alloys, and Stellite alloys resistant to wear and aqueous corrosion. Under normal operating conditions, materials are usually required to have resistance to wear and high temperatures, or to wear and corrosion; in some cases, they are even expected to resist all three of these factors at the same time. It is precisely in such complex operating conditions that the advantages of Stellite alloys become evident. Typical grades and microstructures: The typical grades of Stellite alloys include Stellite1, Stellite4, Stellite6, Stellite8, Stellite12, Stellite20, Stellite31, Stellite100, etc. In our country, research on Stellite superalloys has been conducted in a relatively thorough and in-depth manner (the main domestic research institutions and organizations involved in this field include the Iron and Steel Research Institute and Beijing Rongpin Technology Co., Ltd.). Unlike other superalloys, Stellite superalloys are not strengthened by ordered precipitate phases that are firmly bonded to the matrix; instead, they are composed of an austenitic fcc matrix that has been strengthened by solid solution, along with a small amount of carbides dispersed within the matrix. The casting of Stellite superalloys relies to a large extent on carbide strengthening. Pure cobalt crystals have a hexagonal close-packed (hcp) crystal structure below 417°C, and transform to an fcc structure at higher temperatures. To prevent such a transformation in Stellite superalloys during use, all Stellite alloys are actually nickel-alloyed in order to stabilize their microstructure within the range from room temperature to the melting point. Stellite alloys exhibit a flat fracture stress-temperature relationship, but they show superior resistance to thermal corrosion at temperatures above 1000°C compared to other materials at such high temperatures; this is likely due to their high chromium content, which is a characteristic of these alloys. The Incoloy series of alloys is divided into three types: Incoloy 800, Incoloy 800H, and Incoloy 800AT. These are nickel-iron-chromium alloys that resist high-temperature oxidation and carburization. This alloy contains 32% nickel, which enables it to resist stress corrosion cracking caused by chlorides and makes it insensitive to the precipitation of the σ-phase. This alloy exhibits excellent resistance to uniform corrosion. In the solution-treated state, 800H and 800AT alloys exhibit excellent resistance to creep and stress cracking. The three aforementioned different 800 alloys have been included as structural materials in ASME Boiler and Pressure Vessel Code, Volume I: Power Station Boilers, Volume III: Nuclear Power Boilers, and Volume VIII: Non-Fire Pressure Vessels. The 800 and 800H, 800AT alloys have the same chemical composition except for their different carbon contents; in addition, the 800AT alloy also contains 1% aluminum and titanium. 800 alloy is generally used in temperature environments of around 593°C. 800H and 800AT alloys are typically used in environments at around 593°C where higher resistance to creep and stress cracking is required.