Silicon steel sheet
Silicon steel is commonly known as silicon steel sheet or silicon steel sheet. It is an indispensable low-carbon ferrosilicon soft magnetic alloy in the power, electronics and military industries. It is also the metal functional material with the largest output. Its output accounts for about 1% of the world's steel output. It is a ferrosilicon alloy with a silicon content of 0.8%-4.8%, which is hot and cold rolled into a silicon steel sheet with a thickness of less than 1mm. ·Adding silicon can increase the resistivity and maximum permeability of iron, reduce coercivity, core loss (iron loss) and magnetic aging. It is mainly used as the core of various motors, generators and transformers.
Silicon steel sheet classification
Silicon steel sheets can be divided into low silicon and high silicon according to their silicon content.
1. Low silicon wafer
Low silicon wafers contain less than 2.8% silicon, which has certain mechanical strength and is mainly used to manufacture motors, commonly known as silicon steel sheets for motors;
2. High silicon wafer
The silicon content of high silicon wafer is 2.8%-4.8%. It has good magnetic properties but is relatively brittle. It is mainly used to make transformer cores, commonly known as transformer silicon steel sheets. There is no strict boundary between the two in actual use, and high-silicon wafers are often used to manufacture large motors.
Classified by production process
can be divided into two types: hot rolled and cold rolled
Cold rolling can be divided into two types: non-oriented grain and grain orientation: cold-rolled sheets have uniform thickness, good surface quality, and high magnetic properties. Therefore, with the development of industry, hot-rolled sheets have a tendency to be replaced by cold-rolled sheets.
Cold rolled silicon steel sheet
Cold-rolled silicon steel sheet is divided into two kinds of steel strips: non-oriented grain and grain oriented.
Non-oriented grain cold-rolled strips are usually used as iron cores for motors or welding transformers; grain-oriented cold-rolled strips are used as iron cores for power transformers, pulse transformers, magnetic amplifiers, etc. The cold-rolled oriented thin silicon steel strip is made of 0.30 or 0.35mm thick oriented silicon steel strip, which is then pickled, cold rolled and annealed.
The cold-rolled non-oriented silicon steel sheet is the hot-rolled steel billet or continuous casting billet into a coil with a thickness of about 2.3mm. Cold-rolled electrical steel strip has the characteristics of flat surface, uniform thickness, high stacking coefficient, good punching performance, etc., and has higher magnetic induction and lower iron loss than hot-rolled electrical steel strip.
Using cold strip instead of hot rolled strip to manufacture motors or transformers, its weight and volume can be reduced by 0%-25%. If cold-rolled oriented tape is used, the performance is better. Using it instead of hot-rolled or low-grade cold-rolled tape can reduce transformer power consumption by 45%-50%, and transformer performance is more reliable.
Definition of non-oriented silicon steel sheet
Non-oriented silicon steel sheet is a silicon steel sheet with a non-oriented deformation texture crystalline structure formed according to a certain production process.
Oriented silicon steel sheet
In the early 1920s, William (Williams) studied single crystals in ferrosilicon and found that um=1400000 in the {100} direction of the easy axis of magnetization. He believed that it should be excellent in the {100} axis in the polycrystalline plate. Performance.
In 1926, the Japanese Honda Mao discovered that the crystallographic direction of iron is the easiest to magnetize, or the direction of the crystal grain cube edge is the easiest to magnetize direction.
In 1934, the American NPGoss successfully developed oriented silicon steel sheets in the laboratory. He used a combination of cold rolling and high temperature heat treatment to make the crystal grains in the silicon steel sheets arranged in an orderly manner along the rolling direction. magnetic.
In 1935, Goss published an article in "TransAmer.Soc.Metals", introduced the research results, and applied for a British patent (No. 442211).
In the same year, Armco of the United States began industrial production of cold-rolled oriented silicon steel sheets. In the 1940s, both Armco and Allegheny produced high-quality oriented silicon steel sheets for transformers. Armco's brand name is Tran-cor (Westinghouse called Hipersil); Allegeny's brand name is Silicon (GE Company called Corosil).
In 1953, Japan tried to produce cold-rolled oriented silicon steel sheets.
In 1958, Japan introduced Armco's patented technology to start the industrial production of cold-rolled oriented silicon steel sheets, and on this basis, continuous improvements have made the performance of Japanese cold-rolled silicon steel sheets reach the highest level in the world.
The single-oriented silicon steel sheet has low magnetic permeability in the direction perpendicular to the rolling direction. In order to overcome this shortcoming, the German vacuum melting company invented the dual-oriented silicon steel sheet in the 1940s.
In 1957, GE and Westinghouse in the United States also produced dual-oriented silicon steel sheets almost simultaneously. In the 1960s, the Kawasaki and Yawata factories in Japan also successfully developed dual-oriented silicon steel sheets. Its magnetic properties in the rolling direction and the vertical direction are similar to those of the single-oriented silicon steel sheet in the rolling direction. The crystal grains of this silicon steel sheet are cubic.
In 1968, Japan's Nippon Steel Plant began to industrially produce high-permeability oriented silicon steel sheets. Its commercial name is "Orientcore Hi-B", or "Hi-B" for short; in 1972, large-lattice high-permeability oriented silicon steel was developed In 1981, a small-lattice high-permeability oriented silicon steel sheet was further developed; in 1982, Japan began to produce surface laser irradiation treatment (ZDKH) high-permeability oriented silicon steel sheet, which further reduced iron loss.
In 1988, Japan developed a high-permeability oriented silicon steel sheet using mechanical methods to form the micro-stress method (ADMH). Views on the development of grain-oriented silicon steel sheet from Nippon Steel Corporation. In the 1950s, the performance of single-oriented silicon steel sheets in several countries. ·Between 1955 and 1975, the quality of oriented silicon steel sheet and non-oriented silicon steel sheet in Japan changed. From 1880 to 1970, the declining curve of core steel sheet iron loss.
Non oriented silicon steel
