The Role of Alloy Element Si in Stainless Steel
The Role of Silicon in Stainless Steel
CHONGQING WORLD STEEL CO.,LTD
1、 The Effect of Silicon on the Microstructure and Heat Treatment of Steel
1) As an alloying element in steel, Si generally has a mass fraction of not less than 0.4% and exists as a solid solution in ferrite or austenitic stainless steel, which can reduce the austenite phase zone.
2) Increase annealing, normalizing, and quenching temperatures to improve hardenability in hypoeutectoid steel.
3) Silicon does not form carbides and can strongly promote the graphitization of carbon. In medium and high carbon steels with high silicon content, if they do not contain strong carbide forming elements, graphitization can easily occur at a certain temperature.
4) In carburized steel, silicon can reduce the thickness of the carburized layer and the concentration of carbon.
5) Silicon has a good deoxygenation effect on molten steel.
Stainless steel 310S is a heat-resistant and high-temperature resistant stainless steel, which has been well promoted. 310S seamless stainless steel pipe / tubes are also used on the rollers of annealing furnaces, and the Si content of 314 is better than 310S. Therefore, the heat resistance of 314 stainless steel seamless pipe is higher,
2、 The Effect of Silicon on the Mechanical Properties of Steel
1) Improving the hardness and strength of ferrite and austenite has a stronger effect than manganese, nickel, chromium, tungsten, aluminum, vanadium, etc; Significantly improve the elastic limit, yield strength, and yield strength ratio of steel, and increase fatigue strength.
2) When the mass fraction of silicon exceeds 3%, the plasticity and toughness of steel significantly decrease.
3) Forming a banded structure in the steel, resulting in lower transverse performance than longitudinal performance.
4) Improve the wear resistance of steel.
3、 The Influence of Silicon on the Physics, Chemistry, and Processing Technology of Steel
1) Reduce the density, thermal conductivity, conductivity, and resistance temperature coefficient of steel.
2) The eddy current loss of silicon steel sheets is significantly lower than that of pure iron, and the coercivity, magnetic resistance, and hysteresis losses are lower. The permeability and magnetic induction strength are higher.
3) Improve the oxidation resistance of steel at high temperatures.
4) Deteriorates the weldability of steel.
5) Steel with a mass fraction of silicon exceeding 2.5% has difficulty in plastic processing.
4、 Application of Silicon in Steel
1) In ordinary low alloy steel, it can increase strength, improve local corrosion resistance, and in quenched and tempered steel, it can improve hardenability and resistance to tempering. It is one of the main alloy components in the multi element alloy structure.
2) SiMn or SiMnB steel with a mass fraction of 0.5% -2.8% silicon is widely used as high load spring materials, and strong carbides such as tungsten, vanadium, molybdenum, niobium, and chromium are added to form elements.
3) Silicon steel sheet is a low-carbon steel and ultra-low-carbon steel with a mass fraction of 1.0% -4.5% silicon, used for motors and transformers
4) In stainless steel and corrosion-resistant steel, it is combined with molybdenum, tungsten, chromium, aluminum, titanium, nitrogen, etc. to improve corrosion resistance and high-temperature oxidation resistance. The statue made of stainless steel and corrosion-resistant steel is as durable as new.
TP 310S (old grade 0Cr25Ni20/new grade 06Cr25Ni20 in CHINA ) is an austenitic chromium nickel stainless steel with excellent oxidation resistance and corrosion resistance. Due to the high percentage of chromium and nickel, 310S has much better creep strength and can operate continuously at high temperatures, with good high temperature resistance.
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AISI 310S / EN 1.4845 is an austenitic stainless steel with excellent heat resistance and strength at high temperatures. The anti scaling ability in air is 1050 ° C (for higher temperatures, we recommend material AISI 314/EN 1.4841). This stainless steel grade is very suitable for welding, forging, and cold forming. Typical application areas are equipment engineering, furnace construction, or chemical industry.
310S It has good oxidation resistance, corrosion resistance, acid and alkali resistance, and high temperature resistance. High temperature resistant steel pipes are specially used for manufacturing electric furnace tubes and other occasions
AISI310S Physical Characteristics:
Magnetization: None
Density (kg/dm ³)： 7,9
Thermal conductivity (maximum 20 ° C): 15
Room temperature electronic resistance (Ω mm ²/ m) : 0,85
