45 Beneficial effects of ferrosilicon powder: According to the current standards in my country, ship plate steel is usually divided into general-strength hull steel plates and high-strength hull steel plates. High-strength hull steel plates can be divided into three strength grades: 32Kg, 36Kg, and 40Kg according to the yield point, and four quality grades of AH, DH, EH, and FH. Among them, the commonly used three grades are AH, DH, and EH. With the rapid development of the shipbuilding industry, the requirements for ship plate grades are getting higher and higher, and the demand for FH grade high-strength hull steel plates is also increasing. This grade of high-strength hull steel plates requires high strength and good low-temperature impact toughness.
Application of 45 ferrosilicon powder in my country: At present, there are many steel mills in China producing 36 steel plate, which usually adopts TMCP production process. A certain strengthening effect is achieved without adverse effects on the structure of the steel, and the steel plate has a lower brittle transition temperature and good welding performance. Therefore, the steel plate has extremely strict requirements on welding materials, not only requiring good strength and toughness matching of the weld metal, but also requiring a certain low-temperature impact toughness, requiring KV2 (-60°C)>27J. In the development process of welding materials, on the basis of meeting the minimum requirements, a certain allowance for low temperature impact toughness must be reserved.
The deposited metal of the electrode contains the following chemical compositions by weight: c < 0.12%, Si < 0.80%, Mn < 1.25%, Ni 2.00~2.75%, S < 0.030%, P < 0.030%, and the rest are Fe, which have High toughness KV2 (-60 ℃) ^ 27J.In order to improve the low temperature impact toughness of the weld deposit metal, 45 ferrosilicon powder strictly controls the impurity elements such as sulfur, phosphorus, oxygen, nitrogen in the deposited metal; The addition of rare earth elements further achieves the effect of removing sulfur, phosphorus and refining grains, thereby further improving the low temperature impact toughness of the deposited metal.
45 Ferrosilicon powder: The main function is deoxidation and alloying. If the content is too small, the deoxidation of the weld metal will be insufficient; if the content is too large, the strength of the weld metal will be too high, and at the same time, the low temperature impact toughness of the weld metal will be reduced. 45 ferrosilicon powder (complies with GB/T2272-2009), the content of 45 ferrosilicon powder is between 4 and 6.