Introduction to Nickel and Nickel Alloys

Nickel and nickel alloys are an important type of strategic materials, possessing excellent properties such as extremely good corrosion resistance, high strength at high temperatures, excellent processing properties, as well as special electromagnetic and memory-like functional properties. Their processed materials are high-value-added products and are one of the hot research metals at home and abroad. Nickel alloys are a class of alloys prepared by adding alloying elements to pure nickel. According to the nickel content, they are divided into two types: those with nickel as the base (Ni content ≥ 50%), and containing other alloying elements are called nickel-based alloys; when the Ni content is 30% - 50% and Fe + Ni ≥ 60%, they are called iron-nickel-based alloys.

Nickel alloys can be classified according to their application purposes as:

high-temperature alloys, corrosion-resistant alloys, memory alloys, wear-resistant alloys and precision alloys. Nickel alloys possess excellent corrosion resistance, high-temperature strength, and oxidation resistance. Some special alloys also have memory properties, excellent electromagnetism and other special functional properties, thus being widely used in industrial fields such as military aerospace, aerospace navigation, electrical and electronic engineering, petrochemicals, new energy, etc.

Nickel and nickel alloys exhibit excellent corrosion resistance in many media. Different types can play an indispensable role in reducing/oxidizing acids, bases, salts, chloride ions and other media. They are currently the most complete and versatile corrosion-resistant alloy material system. According to their corrosion resistance, their main classifications and applications are as follows: Ni is used for strong alkalis, Ni-Cu for reducing acids, Ni-Mo for reducing acids, Ni-Fe-Cr for oxidizing acids, Ni-Cr-Si for super oxidizing acids, and Ni-Cr-Mo for strong alkalis and all acids.  

Development Requirements

The chemical industry typically uses pure nickel in areas such as corrosion-resistant structural components for chemical equipment, precision instruments, electronic tubes, and radio equipment parts. High-purity nickel N4 has a large demand in industries like electrolysis and electroplating, mainly in wide-width medium-thick plates. Ultra-pure nickel is applied in battery and other related fields. Pure nickel with a thickness of 0.5mm to 0.6mm and N10276 cold-rolled thin plates have a significant demand in the manufacturing of plate heat exchangers. Iron-nickel corrosion-resistant alloys N08020 and N08028, as well as other sheet materials, are widely used in the preparation of oil and gas transmission pipelines. N08825 and pipeline steel composite pipes have a large demand in the petroleum industry. Nickel-based corrosion-resistant alloys N06600, N04400, N06625, and N10276 have excellent corrosion resistance and a large market demand. Previously, a large amount of these were imported, but now there is a gradual process of domestic production. Equipment manufacturing aims to reduce costs, minimize welds, and enhance safety. In this industry, the main demand is for wide-width medium-thick plates, with a thickness greater than 6mm, a width greater than 1800mm, and a length of more than 5000mm.

Demand in the field of electrical and electronic engineering

The functional materials of nickel alloys for electronics and electrical applications are an important aspect of the application of nickel alloys, mainly used in household appliances, IT manufacturing, information products, and electrical product manufacturing, etc. For example, the demand for nickel alloy strips used in color TV manufacturing is very large, and the domestic production rate is less than 10%, which provides an opportunity for the development of nickel-based precision alloys. However, it requires high technical capabilities and equipment strength.

Demand in the nuclear power and new energy field

Nickel-based superalloys have excellent high-temperature resistance, corrosion resistance, or certain specific environmental adaptability. In 2018, there were 7 nuclear power units in China that officially entered commercial operation. Although the annual new capacity of the nuclear power industry has significant fluctuations, it still maintains a growth trend in the long term. In the nuclear power equipment manufacturing industry, superalloy materials have an irreplaceable role due to their excellent characteristics such as high-temperature resistance and high strength, and are mainly used in the nuclear island where nuclear reactions are carried out. The components in nuclear power equipment that mainly use superalloys include fuel assemblies, control rods, pressure vessels, evaporators, and high-temperature gas furnace heat exchangers, etc. These components need to withstand temperatures of 600°C to 800°C during operation and require high creep strength, and must use superalloy materials.

Demand in the aerospace field

At present, the nickel-based superalloys urgently needed in China's aerospace field are far behind those of foreign countries. The turbine blades used in engines of large aircraft projects, aviation projects, and military aircraft urgently need high-performance superalloys. After several generations of development, the advanced aviation engines of foreign countries have all adopted single crystal superalloys to manufacture single crystal turbine blades, which is a very difficult technology. There are many defects in the manufacturing of blades in domestic production. The research on single crystal superalloy materials and blade manufacturing in China is weak, and the manufacturing technology of aerospace superalloys has become a key factor restricting the development of related industries in China.

Demand in the medical field

Titanium-nickel shape memory alloys are widely used in areas such as human heart stents and dental orthodontics. At the same time, emerging industries such as aerospace, automobiles, and robots have also shown a rapid growth trend in demand for shape memory alloys.