Nikkelipohjainen seos
Nickel-based alloy refers to a type of alloy that has comprehensive properties such as high strength and certain resistance to oxidation and corrosion at high temperatures of 650~1000°C. According to the main properties, they are further divided 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. High-temperature alloys are divided into iron-based high-temperature alloys, nickel-based high-temperature alloys and cobalt-based high-temperature alloys according to different substrates. Among them, nickel-based high-temperature alloys are referred to as nickel-based alloys.
Corrosion resistant alloy
The main alloying elements are copper, chromium and molybdenum. It has good comprehensive performance and can resist various acid corrosion and stress corrosion. The earliest application (produced in the United States in 1905) is nickel-copper (Ni-Cu) alloy, also known as Monel alloy (Monel alloy Ni 70 Cu30); in addition, there are nickel-chromium (Ni-Cr) alloy (that is, nickel-based heat-resistant alloy , hot corrosion-resistant alloys among corrosion-resistant alloys), nickel-molybdenum (Ni-Mo) alloys (mainly refers to Hastelloy B series, domestic professional corrosion-resistant alloy production companies include Beijing Iron and Steel Research Institute, Baoti Group Rare Metal Materials companies, etc.), nickel-chromium-molybdenum (Ni-Cr-Mo) alloy (mainly refers to Hastelloy C series, domestic professional corrosion-resistant alloy production companies include Beijing Iron and Steel Research Institute, Beijing Rongpin Technology Co., Ltd., Baoti Group Rare Metal Materials Company, etc.) etc. At the same time, pure nickel is also a typical representative of nickel-based corrosion-resistant alloys. These nickel-based corrosion-resistant alloys are mainly used to manufacture parts for various corrosion-resistant environments such as petroleum, chemical industry, electric power, etc.
Nickel-based corrosion-resistant alloys mostly have an austenitic structure. In the solid solution and aging treatment state, there are intermetallic phases and metal carbonitrides on the austenite matrix and grain boundaries of the alloy. Various corrosion-resistant alloys are classified according to their composition and their characteristics are as follows:
The corrosion resistance of Ni-Cu alloy is better than that of nickel in reducing media, and its corrosion resistance is better than copper in oxidizing media. It is resistant to high temperature fluorine gas, hydrogen fluoride and hydrogen fluoride in the absence of oxygen and oxidant. The best material for acids (see Metal Corrosion).
Ni-Cr alloy is a nickel-based heat-resistant alloy; it is mainly used under oxidizing media conditions. Resistant to high temperature oxidation and corrosion from gases containing sulfur, vanadium and other gases, its corrosion resistance increases with the increase in chromium content. This type of alloy also has good resistance to hydroxide (such as NaOH, KOH) corrosion and stress corrosion resistance.
Ni-Mo alloy is mainly used under conditions of reducing medium corrosion. It is the best alloy to resist hydrochloric acid corrosion, but in the presence of oxygen and oxidants, the corrosion resistance will decrease significantly.
Ni-Cr-Mo(W) alloy has the properties of the above-mentioned Ni-Cr alloy and Ni-Mo alloy. Mainly used under oxidation-reduction mixed media conditions. This type of alloy has good corrosion resistance in high-temperature hydrogen fluoride gas, in hydrochloric acid and hydrofluoric acid solutions containing oxygen and oxidants, and in wet chlorine gas at room temperature.
Ni-Cr-Mo-Cu alloy is resistant to both nitric acid and sulfuric acid corrosion, and also has good corrosion resistance in some oxidation-reduction mixed acids.
Application areas
Nickel-based alloys are used in many fields, such as:
1. Ocean: Marine structures in the marine environment, seawater desalination, seawater aquaculture, seawater heat exchange, etc.
2. Environmental protection field: flue gas desulfurization equipment for thermal power generation, wastewater treatment, etc.
3. Energy field: atomic power generation, comprehensive utilization of coal, wave power generation, etc.
4. Petrochemical industry: oil refining, chemical and chemical equipment, etc.
5. Food field: salt production, soy sauce brewing, etc. In many of the above fields, ordinary stainless steel 304 is not competent. In these special fields, special stainless steel is indispensable and cannot be replaced.
Wear resistant alloy
The main alloying elements are chromium, molybdenum, and tungsten, and also contain small amounts of niobium, tantalum, and indium. In addition to its wear resistance, it also has good anti-oxidation, corrosion resistance and welding properties. It can be used to manufacture wear-resistant parts, and can also be used as a coating material to cover the surface of other base materials through surfacing and spraying processes.
Nickel-based alloy powders include self-fluxing alloy powder and non-self-fluxing alloy powder.
Non-self-fluxing nickel-based powder refers to nickel-based alloy powder that does not contain B, Si or has low B and Si content. This type of powder is widely used in plasma arc spray coatings, flame spray coatings and plasma surface strengthening. Mainly include: Ni-Cr alloy powder, Ni-Cr-Mo alloy powder, Ni-Cr-Fe alloy powder, Ni-Cu alloy powder, Ni-P and Ni-Cr-P alloy powder, Ni-Cr-Mo-Fe Alloy powder, Ni-Cr-Mo-Si high wear-resistant alloy powder, Ni-Cr-Fe-Al alloy powder, Ni-Cr-Fe-Al-B-Si alloy powder, Ni-Cr-Si alloy powder, Ni- Cr-W-based wear-resistant and corrosion-resistant alloy powder, etc.
Adding appropriate amounts of B and Si to nickel alloy powder forms nickel-based self-fluxing alloy powder. The so-called self-fluxing alloy powder, also known as eutectic alloy and hard facing alloy, is a series of powders formed by adding alloy elements (mainly boron and silicon) that can form low melting point eutectics to nickel, cobalt, and iron-based alloys. Material. Commonly used nickel-based self-fluxing alloy powders include Ni-B-Si alloy powder, Ni-Cr-B-Si alloy powder, Ni-Cr-B-Si-Mo, Ni-Cr-B-Si-Mo-Cu, High molybdenum nickel-based self-fluxing alloy powder, high chromium molybdenum nickel-based self-fluxing alloy powder, Ni-Cr-W-C-based self-fluxing alloy powder, high copper self-fluxing alloy powder, tungsten carbide dispersion nickel-based self-fluxing alloy powder Alloy powder, etc.
The role of various elements in alloys:
●The role of boron and silicon elements: significantly lower the melting point of the alloy, expand the solid-liquidus temperature zone, and form a low-melting eutectic; deoxidation reduction and slagging functions; hardening and strengthening effects on the coating; and improvement of operating process performance
●The role of copper element: improve corrosion resistance to non-oxidizing acids
●The role of chromium element: solid solution strengthening and passivation; improving corrosion resistance and high temperature oxidation resistance; excess chromium easily forms chromium carbide and chromium boride hard phases with carbon and boron to improve alloy hardness and wear resistance sex
●The role of molybdenum element: its large atomic radius causes large distortion of the crystal lattice after solid solution, significantly strengthens the alloy matrix, improves the high-temperature strength and red hardness of the matrix; it can cut and reduce the network structure in the coating; and improves gas resistance Erosion and erosion ability.
precision alloy
Including nickel-based soft magnetic alloy, nickel-based precision resistance alloy and nickel-based electrothermal alloy, etc. The most commonly used soft magnetic alloy is Permalloy, which contains about 80% nickel. It has high maximum magnetic permeability and initial magnetic permeability and low coercive force. It is an important iron core material in the electronics industry. The main alloying elements of nickel-based precision resistance alloy are chromium, aluminum, and copper. This alloy has high resistivity, low temperature coefficient of resistivity and good corrosion resistance, and is used to make resistors. Nickel-based electric heating alloy is a nickel alloy containing 20% chromium. It has good anti-oxidation and anti-corrosion properties and can be used for a long time at temperatures of 1000~1100°C.
Memory Alloy
Nickel alloy containing 50(at)%titanium.html> titanium. Its recovery temperature is 70°C and its shape memory effect is good. A small change in the proportion of nickel-titanium components can change the recovery temperature within the range of 30 to 100°C. It is mostly used to manufacture automatic opening structural parts used in spacecraft, self-exciting fasteners used in the aerospace industry, artificial heart motors used in biomedicine, etc.
Representative materials of nickel-based alloys include:
1. Incoloy alloy, such as Incoloy800, the main component is; 32Ni-21Cr-Ti, Al; it is a heat-resistant alloy;
2. Inconel alloy, such as Inconel600, the main component is; 73Ni-15Cr-Ti, Al; it is a heat-resistant alloy;
3. Hastelloy alloy, such as Hastelloy C-276, the main component is; 56Ni-16Cr-16Mo-4W; it is a corrosion-resistant alloy;
4. Monel alloy, that is, Monel alloy, such as Monel 400, the main component is; 65Ni-34Cu; it is a corrosion-resistant alloy;
Product Usage
aerospace industry
Maintains good mechanical strength at extremely high temperatures
Aircraft engines, gas turbines, engine valves
energy industry
Good resistance to high temperature vulcanization and high temperature oxidation
Furnace parts, insulation, heat treatment industry, oil and gas industry
petrochemical industry
Resistant to corrosion by aqueous solutions (acid, alkali, chloride ions)
Desalination plants, petrochemical transmission pipelines
Electronics/Optoelectronics General Industry
Generally resistant to corrosion or high temperature environments with low degree of resistance
Battery cases, lead frames, computer monitor grilles
