Nickel-based alloy is a kind of alloy with comprehensive properties such as high strength and certain anti-oxidation and corrosion resistance under 650 ~ 1000 ℃ high temperature. In accordance with the main performance and subdivided into nickel-based heat-resistant alloys, nickel-based corrosion resistant alloys, nickel-based wear-resistant alloys, nickel-based precision alloys and nickel-based shape memory alloys. Superalloy According to the different matrix, divided into: iron-based superalloy, nickel-based superalloy and cobalt-based superalloy. Nickel-based superalloy which is also called as nickel alloy for short.
Nickel-based corrosion resistant alloy with more austenitic tissue. In solution and aging treatment, the alloy austenite matrix and the grain boundary there are intermetallic phases and metal carbonitride exist, all kinds of corrosion resistant alloys by composition and its characteristics are as follows:
Ni-Cu alloy corrosion resistance in reducing medium is better than nickel, and corrosion resistance in the oxidizing medium is better than copper, it is in the absence of oxygen and oxidant conditions, is resistant to high temperature fluorine gas, hydrogen fluoride and hydrofluorocarbon The best acid material (see metal corrosion).
Ni-Cr alloy is nickel-based heat-resistant alloy; mainly used in oxidizing media conditions. High temperature oxidation and sulfur, vanadium and other gases, the corrosion resistance increases with the increase of chromium content. Such alloys also have better resistance to hydroxide (such as NaOH, KOH) corrosion and stress corrosion resistance.
Ni-Mo alloy is mainly used in the conditions of reducing media corrosion. It is the best corrosion resistant hydrochloric acid alloy, but in the presence of oxygen and oxidants, the corrosion resistance will be significantly reduced.
Ni-Cr-Mo (W) alloy combines the above-mentioned Ni-Cr alloy, Ni-Mo alloy performance. Mainly in the oxidation – reduction mixed media conditions. These alloys are highly resistant to corrosion in high temperature hydrogen fluoride gas in hydrochloric and hydrofluoric acid solutions containing oxygen and oxidants, and in wet chlorine at room temperature.
Ni-Cr-Mo-Cu alloy has both nitric acid and sulfuric acid corrosion resistance, in some oxidation-reduction mixed acid also has good corrosion resistance.
Nickel-based alloys in many areas, such as:
1, the ocean: marine environment marine structures, desalination, mariculture, sea water heat exchange.
2, the field of environmental protection: thermal power flue gas desulfurization equipment, wastewater treatment.
3, the energy field: atomic power generation, comprehensive utilization of coal, tidal power generation.
4, petrochemical areas: oil refining, chemical and chemical equipment.
5, food areas: salt, soy sauce brewing. In many of these areas, ordinary stainless steel 304 is not competent, in these special areas, special stainless steel is indispensable, but also can not be replaced. In recent years, with the rapid economic development, more and more projects require higher grades of stainless steel as the level of industrial fields continues to increase. With various industries on the growth of the demand for nickel-based alloys. In 2011, China's nickel-based alloy market reached 23.07 billion yuan, an increase of 19.47%. Therefore, the industry development level is in a steady upward trend.
Post time: Nov-10-2017