441 stainless steel: Corrosion resistance at high temperatures

Chemical composition and element analysis:

441 stainless steel is a ferritic stainless steel known for its excellent high-temperature corrosion resistance. The following are the main chemical components of 441 stainless steel:

Carbon (C) : ≤0.030%, ensuring the purity of the material.

Silicon (Si) : ≤1.00%, helps to maintain suitable processing properties.

Manganese (Mn) : ≤1.00%, has a limited effect on mechanical properties.

Phosphorus (P) : ≤0.040%, to ensure the high quality of the material.

Sulfur (S) : ≤0.015%, improved corrosion resistance.

Chromium (Cr) : 17.50~18.50%, providing excellent corrosion resistance.

Nickel (Ni) : Allowed, ≥0.60%, helps to improve corrosion resistance.

Molybdenum (Mo) : Not provided.

Nitrogen (N) : Not provided.

Copper (Cu) : Not provided.

Other elements: Titanium (Ti) : 0.10~0.60, niobium (Nb) : ≥0.30+3C.

Physical properties:

Density (20 ° C) : 7.7 kg/dm³, making 441 stainless steel with high strength and rigidity under the same weight.

Melting point: Not provided, but in general, ferritic stainless steel has a low melting point and is easy to process and form.

Specific heat capacity (0~100℃) : 0.46kg /(kg·K), indicating that 441 stainless steel has good thermal conductivity.

Thermal conductivity (100℃) : 35.1W /(m·K), indicating that it can still maintain stable thermal conductivity at high temperatures.

Resistivity (20℃) : 0.6Ω ·mm²/m, which is conducive to reducing the loss when the current passes through.

The longitudinal elastic modulus (20℃) : 200 GPa, indicating that 441 stainless steel has good tensile strength and ductility.

Magnetism: Yes, it indicates that it contains a certain amount of iron and may have a certain magnetism.

Mechanical properties: the delivery state is solid solution treatment of bar and solid solution pickling of plate, so that it has good corrosion resistance and mechanical properties. Tensile strength (RM/MPa) : 430 MPa, extension strength (Rp0.2/MPa) : 250 MPa, elongation (A/%) : 18% and other indicators show high strength and toughness. Section shrinkage (Z/%) : not provided, but usually the section shrinkage of ferritic stainless steel is low, which is conducive to maintaining the stability of the overall structure.

Heat treatment: hardness annealing hardness (HBW) ≤217, hardness HRB≤96, indicating that after proper heat treatment, 441 stainless steel can obtain lower hardness and good toughness. Heating temperature: 800~1050℃, suitable for a variety of application scenarios. Heating method: Fast cooling, can quickly cool the material from the high temperature state to room temperature, to avoid too long holding time to cause the grain growth and performance decline of the material.

Application analysis:

441 stainless steel is known for its excellent high-temperature corrosion resistance and is mainly used in the following fields:

Exhaust system: 441 stainless steel is widely used in automotive exhaust manifold and front pipe and other components. Its high temperature resistance can reach about 750-950 degrees Celsius, making it the main raw material for manufacturing exhaust systems. With the improvement of emission standards, more and more automobile manufacturers are choosing 441 stainless steel to meet the challenges of high temperature and corrosion. In addition, 441 stainless steel can also be used in other high-temperature environment equipment and pipelines, such as boilers, petrochemical equipment, power equipment and so on.

To sum up, 441 stainless steel is favored for its stability and corrosion resistance in high temperature environments, which is especially suitable for automotive exhaust systems to ensure the reliability and durability of emission systems under harsh conditions.