Silicon steel , also known as electrical steel , is an extremely low carbon ferrosilicon alloy material with a silicon content of 0.5% to 4.5%. It has the characteristics of high permeability, low coercivity and large resistivity, so the hysteresis loss and eddy current loss are small. Silicon steel is mainly used as magnetic material in motors , transformers , electrical appliances and electrical instruments . In order to meet the needs of punching and shearing processing when manufacturing electrical appliances, silicon steel also requires a certain plasticity. In order to improve the magnetic susceptibility and reduce the hysteresis loss, the harmful impurity content is required to be as low as possible, and the plate shape is required to be flat and the surface quality is good. 12

According to the different production process, silicon steel can be divided into hot-rolled silicon steel  and cold-rolled silicon steel. Hot rolled silicon steel can be divided into hot rolled low silicon steel and hot rolled high silicon steel , respectively, used in the manufacture of household motors and micro-motors and transformer manufacturing. Cold-rolled silicon steel is divided into non-oriented silicon steel  and oriented silicon steel , non-oriented silicon steel is mainly used in the manufacture of motors and generators, and oriented silicon steel is mainly used in the manufacture of transformer core. 3

Unoriented silicon steel is a ferrosilicon alloy with very low carbon content, and its grains are randomly oriented in deformed and annealed steel plates. It is commonly used in the manufacture of electric motors and generators. 4

The development prospects of silicon steel are considerable, and the national policy encourages and supports the development of silicon steel. In recent years, the output of high-grade unoriented silicon steel for new energy vehicles  has grown fastest, showing the wide application of silicon steel in power, electronics and military industries.

Carbon structural steel plate is steel where the main alloying constituent is carbon, is a low carbon steel that exhibits good strength coupled with formability. It is easy to machine and fabricate and can besecurely welded. The steel can be galvanized to provide increased corrosion resistance.

AISI 4142 steel is ultra-high strength steel, with high strength and toughness, hardenability is also good, no obvious tempering brittleness, high fatigue limit and resistance to multiple shocks after tempering treatment, low temperature impact toughness is good. The steel is suitable for manufacturing large and medium-sized plastic molds requiring certain strength and toughness. High strength, hardenability, good toughness, small deformation during quenching, high creep strength and lasting strength at high temperature. It is used to manufacture forgings requiring higher strength and larger tempering cross-section than 35CrMo steel, such as large gear for locomotive traction, supercharger transmission gear, pressure vessel gear, rear shaft, connecting rod and spring clamp with great load, and can also be used for drilling pipe joints and fishing tools in oil deep Wells below 2000m, and can be used for bending machine molds.

ASTM 4140 is the standard steel number of GB in China, 40Cr steel is one of the most widely used steel in the machinery manufacturing industry. It has good comprehensive mechanical properties, good low temperature impact toughness and low notch sensitivity after tempering. Steel hardenability is good, water quenching can be quenched to 28 ~ 60mm, oil quenching can be quenched to 15 ~ 40mm. In addition to tempering treatment, this steel is also suitable for cyaniding and high-frequency quenching treatment. When the hardness is 174 ~ 229HB, the relative machinability is 60%. The steel is suitable for making medium-sized plastic molds and shaft accessories.

SA387Gr12CL2 steel is a pearlitic heat-resistant steel with high thermal strength (δb≥440MPa) and oxidation resistance at high temperatures, and has a certain ability to resist hydrogen corrosion. Due to the high content of Cr, C and other alloying elements in the steel, the hardening tendency of the steel is obvious.